Hello! Log in or Register   |  Help  |  Donate  |  Buy Shirts  See all banner ads | Advertise on TheSamba.com  
TheSamba.com
 
Second Bus and First Engine Drop. Need guidance!
Page: Previous  1, 2, 3, 4, 5, 6, 7, 8, 9, 10  Next
Forum Index -> Bay Window Bus Share: Facebook Twitter
Reply to topic
Print View
Quick sort: Show newest posts on top | Show oldest posts on top View previous topic :: View next topic  
Author Message
whatdoesthisbuttondo?
Samba Member


Joined: April 05, 2012
Posts: 225
Location: Victoria
whatdoesthisbuttondo? is offline 

PostPosted: Thu Jul 28, 2016 3:32 pm    Post subject: Re: Second Bus and First Engine Drop. Need guidance! Reply with quote

Mmmk, been having issues getting this engine tuned. initial start up idle is up to 2000, hit accelerator, drops to about 1200.

Running into problems with left carb. Followed amskeptics instructions to a T. In pulling the right cut off to set the mixture the left carb totally dies.

- left carb have vacuum signal
- central idling circuit is disengaged
- vacuum hose off
- idling at about 1200. I believe it should be lower...
- throttle stop screws set
- both carbs synched with snail at 2500 and at idle.
- both right and left mixture solenoids working.

Have been having issues with popping and backfiring from muffler which suggests lean running in general . The fact that the left carb dies, when left to its own devices to idle, means its likely running very lean. mixture screw is 2.5 tuns out. opening it way out another couple turns, it still dies when pulling right cut off.

Other than taking carb apart to check passages (did this last year to unclog check ball) do I have other things I can check? Carbs recently rebuilt. fuel filter clean.

Thx!
_________________
1973 Campervan. Stock 1700. Dual Solex carbs. Pertronix electronic points on distributor (stock, not a 009). Engine rebuilt in October 2016.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
busdaddy
Samba Member


Joined: February 12, 2004
Posts: 38240
Location: Surrey B.C. Canada, Land of the giant flying moose!
busdaddy is offline 

PostPosted: Thu Jul 28, 2016 3:35 pm    Post subject: Re: Second Bus and First Engine Drop. Need guidance! Reply with quote

Start by removing the left idle solenoid and seeing if you can blow through it while it's energised by a small jumper wire (you'll have to ground it as well).
Or just swap it with the right one and see if the problem moves with it.
_________________
Rust NEVER sleeps and stock never goes out of style.

Wanted, OG paint 1971 Niagara blue decklid.

Stop dead photo links! Post your photos to The Samba Gallery!
Back to top
View user's profile Send private message Gallery Classifieds Feedback
whatdoesthisbuttondo?
Samba Member


Joined: April 05, 2012
Posts: 225
Location: Victoria
whatdoesthisbuttondo? is offline 

PostPosted: Thu Jul 28, 2016 3:52 pm    Post subject: Re: Second Bus and First Engine Drop. Need guidance! Reply with quote

OKie.. just got back in, problem has morphed. Will go try blowing through that solenoid but something strange happenning now.

battery getting low, but at about 12v from + side to body.

Now the left idle solenoid and CIC solenoid are not clicking over when energized. right solenoid is. all three are getting 8.5v when grounded to body or to respective carb, key tunrned in ignition.

both are coming from plus side of coil, wiring is intact.

Engine also not turning over, but have lights. Hasn't turned over since engine died when pulling right idle solenoid wire.
_________________
1973 Campervan. Stock 1700. Dual Solex carbs. Pertronix electronic points on distributor (stock, not a 009). Engine rebuilt in October 2016.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
whatdoesthisbuttondo?
Samba Member


Joined: April 05, 2012
Posts: 225
Location: Victoria
whatdoesthisbuttondo? is offline 

PostPosted: Thu Jul 28, 2016 4:01 pm    Post subject: Re: Second Bus and First Engine Drop. Need guidance! Reply with quote

Checked right idle solenoid in left carb. I can hear it clicking over.

Left idle solenoid and CIC solenoid still not clicking over. Is there a way these could have both been totally damaged? the CIC was brand new (and not cheap). And both were working half an hour ago...
_________________
1973 Campervan. Stock 1700. Dual Solex carbs. Pertronix electronic points on distributor (stock, not a 009). Engine rebuilt in October 2016.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
busdaddy
Samba Member


Joined: February 12, 2004
Posts: 38240
Location: Surrey B.C. Canada, Land of the giant flying moose!
busdaddy is offline 

PostPosted: Thu Jul 28, 2016 4:19 pm    Post subject: Re: Second Bus and First Engine Drop. Need guidance! Reply with quote

12 volts may not be enough to pull them in, I've seen some that didn't click until you revved the engine and the alternator started charging, once clicked they stayed open.
_________________
Rust NEVER sleeps and stock never goes out of style.

Wanted, OG paint 1971 Niagara blue decklid.

Stop dead photo links! Post your photos to The Samba Gallery!
Back to top
View user's profile Send private message Gallery Classifieds Feedback
whatdoesthisbuttondo?
Samba Member


Joined: April 05, 2012
Posts: 225
Location: Victoria
whatdoesthisbuttondo? is offline 

PostPosted: Thu Jul 28, 2016 10:41 pm    Post subject: Re: Second Bus and First Engine Drop. Need guidance! Reply with quote

Yes, I believe you're right- I need to get a full charge before any more troubleshooting Smile
_________________
1973 Campervan. Stock 1700. Dual Solex carbs. Pertronix electronic points on distributor (stock, not a 009). Engine rebuilt in October 2016.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
whatdoesthisbuttondo?
Samba Member


Joined: April 05, 2012
Posts: 225
Location: Victoria
whatdoesthisbuttondo? is offline 

PostPosted: Mon Aug 08, 2016 9:15 am    Post subject: Re: Second Bus and First Engine Drop. Need guidance! Reply with quote

Alrighty, well the weirdness was mostly low battery sympotoms. Just enough juice to work some solenoids, but not others etc.

Hard to get these carbs working right, however. On cold start up, rpm is immediate 2000 which is good, after a blip on the gas pedal to kick in central idling, rpm drops to about 600 and staggers along. Then once I get driving, within a couple minutes the idling kicks up to almost 2000. Then after a bit more driving (5 min), the idle drops back to 800-900 or a bit under. Lots of popping when letting off gas or coasting downhill.

Had to use this past week of nice weather to get the interior out and look into rust issues. Pics soon.
_________________
1973 Campervan. Stock 1700. Dual Solex carbs. Pertronix electronic points on distributor (stock, not a 009). Engine rebuilt in October 2016.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
whatdoesthisbuttondo?
Samba Member


Joined: April 05, 2012
Posts: 225
Location: Victoria
whatdoesthisbuttondo? is offline 

PostPosted: Mon Aug 08, 2016 12:56 pm    Post subject: Re: Second Bus and First Engine Drop. Need guidance! Reply with quote

Hopefully going to veer away from engines for a while. Going to pull the 2 L out of the other bus and rebuild it nicely with new heads, pistons, cylinders etc. The Camper Special kits are tempting too, but oh so expensive...

I had a lot of fun gutting the bus last week to do some inside-out maintenance of the floor and interior. A bit of a rabbit hole but I am almost ready to get everything back in and do some camper wiring/ set up that I wont have to revisit for a few years.

I did establish that the main bodywork on the front and back was done prior to 1978 (lots of datable stuff, soon to go in 'things found cleaning' thread, overlay cabinets/interior, which overlay bondo work in the back- principle of superposition comes in handy).

Here we are with everything out, as is.

Image may have been reduced in size. Click image to view fullscreen.


A bit of exploring shows some different types of rust, some pitting, and some of these surface tendrils that extend way out as water traveled under the paint (not unlike an esker). You have to chase these with your stripping disk.

Image may have been reduced in size. Click image to view fullscreen.


Here is the worst of the rust, originating from a bad seal on the shore power, and a bit from someone leaving the rear window open. Here it leaves a passage into the space between the middle and outer rocker. Good to seal it now.

Image may have been reduced in size. Click image to view fullscreen.


Here is floor stripped and por 15 metal prep process finished. Worked well on thin rust and pitting, not so good on deeper rust. I also hate the idea of rinsing with water afterwards prior to por 15. Seems like flash rust could be an issue.

Image may have been reduced in size. Click image to view fullscreen.


Por 15 is pretty hard to get right I find. Here is the floor I did 3 or 4 years ago. Has been sitting in a humid environment exposed, but I think the deeper rust is just not dealt with and grows until it splits the thin POR. Not a permanent fix but better than leaving it.

Image may have been reduced in size. Click image to view fullscreen.


Varnished the inside of all panels, and all sub floor pieces.
Image may have been reduced in size. Click image to view fullscreen.


Pulled out the original curtain, very crispy. Yellow stripes down the original..
Image may have been reduced in size. Click image to view fullscreen.


While the cabinet etc is out, it was the right time to replace the seal and deal with sliding door issues. Always a bit gnarly under the seals.
Image may have been reduced in size. Click image to view fullscreen.


Removed a bunch of rust. Found a pinhole.
Image may have been reduced in size. Click image to view fullscreen.


Welded up and POR 15, phosphoric acid hopefully did its thing to convert. Despite rinsing panel below right away, still streaks/lightens paint. Luckily this thing needs a paint job anyways. Touched up a few rust spots overall and it looks a bit better.
Image may have been reduced in size. Click image to view fullscreen.



Image may have been reduced in size. Click image to view fullscreen.


Image may have been reduced in size. Click image to view fullscreen.


Image may have been reduced in size. Click image to view fullscreen.


Poor old bus in the background. Leaning strongly towards just using it as a parts bus. The hours and proper space for the metal work needed are just not there. It has been unbelievably useful however and many parts are getting a good home.

Image may have been reduced in size. Click image to view fullscreen.


more to come.
_________________
1973 Campervan. Stock 1700. Dual Solex carbs. Pertronix electronic points on distributor (stock, not a 009). Engine rebuilt in October 2016.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
whatdoesthisbuttondo?
Samba Member


Joined: April 05, 2012
Posts: 225
Location: Victoria
whatdoesthisbuttondo? is offline 

PostPosted: Tue Feb 14, 2017 2:05 pm    Post subject: Re: Second Bus and First Engine Drop. Need guidance! Reply with quote

Hey all, been lying low and daily driving and the bus has been running fairly well!

Had an issue during a trip this weekend however and ended up towing back home which was luckily within my tow coverage.

Here is the sequence of events and a bit of detail...

Was running great in wind and snow and rain on a remote highway with a lot of short, steep hills. On the way back however, just finished going up a long hill, driving in third at 3500-4000 for 4 or 5 minutes, temps got hottest they had been, about 380C (typically they had been between 200-300).

Headed down the other side, starting to coast in 3rd and BANG, big backfire, not little popps, but full on. Then about 10 more over the next few hundred meters until the motor stalled out and died. Coasted on the shoulder in 2nd to the bottom of the hill and pulled out.

Power good. Gas squirting into carbs. Smoke from right carb where it had been backfiring.

Distributor rotor spinning freely, which was worrisome. Distributor appeared to be seated OK but I didn't check it. It hadn't rotated from when I timed it a couple weeks ago.

Towed the bus home, took out the distributor this morning to check. Once out, rotor spins through the distributor body fine, rotates at the other end, but a bit of newish-looking wear on the lower end.

Looked down the hole into the case, top of distributor drive gear pinion looked normal. Pulled the pinion, looked fine, teeth OK and what I could see of the brass drive gear looked normal. Washer retrieved.

Any thoughts of where I go from here?

Much appreciated!
_________________
1973 Campervan. Stock 1700. Dual Solex carbs. Pertronix electronic points on distributor (stock, not a 009). Engine rebuilt in October 2016.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
timvw7476
Samba Member


Joined: June 03, 2013
Posts: 1022
Location: seattle
timvw7476 is offline 

PostPosted: Tue Feb 14, 2017 6:12 pm    Post subject: Re: Second Bus and First Engine Drop. Need guidance! Reply with quote

When you type: "power good", I'm taking that to mean 12V+ DC to the
instruments & engine, right?
If that is the case, & the engine still rotates, it's time to check compression.
With the story you told it sounds like a valve or valve seat drop descending a steep grade. Time for some cylinder head decisions.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
busdaddy
Samba Member


Joined: February 12, 2004
Posts: 38240
Location: Surrey B.C. Canada, Land of the giant flying moose!
busdaddy is offline 

PostPosted: Tue Feb 14, 2017 6:16 pm    Post subject: Re: Second Bus and First Engine Drop. Need guidance! Reply with quote

whatdoesthisbuttondo? wrote:
Distributor rotor spinning freely, which was worrisome. Distributor appeared to be seated OK but I didn't check it. It hadn't rotated from when I timed it a couple weeks ago.

Sounds to me like you found the problem, is the clamp bent so it doesn't fully seat down in the drive?
_________________
Rust NEVER sleeps and stock never goes out of style.

Wanted, OG paint 1971 Niagara blue decklid.

Stop dead photo links! Post your photos to The Samba Gallery!
Back to top
View user's profile Send private message Gallery Classifieds Feedback
whatdoesthisbuttondo?
Samba Member


Joined: April 05, 2012
Posts: 225
Location: Victoria
whatdoesthisbuttondo? is offline 

PostPosted: Wed Feb 15, 2017 9:00 am    Post subject: Re: Second Bus and First Engine Drop. Need guidance! Reply with quote

Thanks fellas.

Tim, yes 12V to engine. The heads were redone quite recently with new valves and guides, I hope a dropped seat is not the case.

Checked the clamp, its a little twisted across the opening, but that may have been from trying to get it out around the tin.

I have another clamp I will try this weekend and hope it seats OK. Then Ill adjust valves and see if they have changed since last tune up.

Two questions,

1. Is there any way that a backfire could knock the distributor up?

2. Anything special I need to know about getting the pinion gear to mesh back to the drive gear properly once I get the engine to TDC?

Thx
_________________
1973 Campervan. Stock 1700. Dual Solex carbs. Pertronix electronic points on distributor (stock, not a 009). Engine rebuilt in October 2016.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
busdaddy
Samba Member


Joined: February 12, 2004
Posts: 38240
Location: Surrey B.C. Canada, Land of the giant flying moose!
busdaddy is offline 

PostPosted: Wed Feb 15, 2017 10:21 am    Post subject: Re: Second Bus and First Engine Drop. Need guidance! Reply with quote

whatdoesthisbuttondo? wrote:
1. Is there any way that a backfire could knock the distributor up?

No, but a skipping drive could easily cause a backfire. When you get it all bolted down again grab the rotor and pull up as you attempt to twist, you should only feel the few degrees of advance and not be able to rotate it further.

As for the drive it usually takes a couple of stabs before it seats where you want it to, some really sticky grease on the washer helps keep it from falling off in the process.
_________________
Rust NEVER sleeps and stock never goes out of style.

Wanted, OG paint 1971 Niagara blue decklid.

Stop dead photo links! Post your photos to The Samba Gallery!
Back to top
View user's profile Send private message Gallery Classifieds Feedback
whatdoesthisbuttondo?
Samba Member


Joined: April 05, 2012
Posts: 225
Location: Victoria
whatdoesthisbuttondo? is offline 

PostPosted: Tue Jun 20, 2017 11:05 am    Post subject: Re: Second Bus and First Engine Drop. Need guidance! Reply with quote

Follow up to the issue I had with the distributor, all seems to be well after re-installing. Grease on the washer is a great trick, worked well.

Been working on a few things, got the aux fan working again, but the motor was getting super hot and the positive lead was getting smoking hot. Glad I caught that while doing a carb tune up, disconnected for now while I figure out whats going on. If its the electrical the fuse that's in there should have blown; might be the motor itself is on its way out. Changed out some gas lines that were starting to split after 3 months (1/4 inch made in USA stuff, must have been a bad batch, rest are good). Also noticed right carb brass nipple could be pulled out by hand when warm Shocked . Had been running a safety wire to it regardless but was sketchy- took a light punch to the aluminum around the nipple to make it stay put.

Followed Colins carb tuning procedure, been through it a half dozen times now and its almost starting to make sense Laughing . Im going to re-write it for myself with a summary half page version, there are far less actual adjustments than it looks. Great write up though.

Bus runs fantastic while warm and after tuning it had never run better. still a bit of popping coming down hills but minimal. Took slack out of the accelerator and its very responsive.

Couple of issues:

1. Has a very hard time starting now when cold, cranks for ages and only idles at 500 until chokes open. we had adjusted the right choke a bit as it wasn't closing all the way- sticking with a quarter inch gap.

2. when coming to a stop, rpms drop to 500 and then quickly climb back up again. We had the dashpot off for tuning, as I understand it the function is to regulate rpm drop when coming off the accelerator. pretty sure it went back on there OK though.

picked up some NGK BP6et spark plugs, will put those in and mess around a bit more with the chokes, but open to other ideas for tuning so I can get it started and running well from cold... During the procedure nothing needed adjusting wildly out of the 2 1/2 turns out that are the normal starting point for most of the screws. Im finding these carbs finicky, but maybe its just inexperience.

Dreaming of building a 2.1L and might go for some different carbs...
_________________
1973 Campervan. Stock 1700. Dual Solex carbs. Pertronix electronic points on distributor (stock, not a 009). Engine rebuilt in October 2016.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Wildthings
Samba Member


Joined: March 13, 2005
Posts: 35320

Wildthings is offline 

PostPosted: Tue Jun 20, 2017 12:19 pm    Post subject: Re: Second Bus and First Engine Drop. Need guidance! Reply with quote

whatdoesthisbuttondo? wrote:
Also noticed right carb brass nipple could be pulled out by hand when warm Shocked . Had been running a safety wire to it regardless but was sketchy- took a light punch to the aluminum around the nipple to make it stay put.


On single barrel Solex you can get a 1/16" pipe to hose connector to use in place of the pressed in fitting, I would think the same would work with your carbs. For tools you need a 1/16" NPT tap and the correct drill bit to use with it.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
busdaddy
Samba Member


Joined: February 12, 2004
Posts: 38240
Location: Surrey B.C. Canada, Land of the giant flying moose!
busdaddy is offline 

PostPosted: Tue Jun 20, 2017 12:28 pm    Post subject: Re: Second Bus and First Engine Drop. Need guidance! Reply with quote

whatdoesthisbuttondo? wrote:
1. Has a very hard time starting now when cold, cranks for ages and only idles at 500 until chokes open. we had adjusted the right choke a bit as it wasn't closing all the way- sticking with a quarter inch gap. ..

What starting procedure are you using?, I find 2-3 pumps of the throttle and let go then crank works best for me. The chokes shouldn't close fully unless it's ~0*C or colder, at room temperature there should still be ~ 1/4" gap after poking the throttle once to set them. Low idle could be too much choke (unless it dies instantly when you touch the gas), you may have to adjust the length of the high idle links a little to open the throttle plates a little more when the chokes are closed.

whatdoesthisbuttondo? wrote:
2. when coming to a stop, rpms drop to 500 and then quickly climb back up again. We had the dashpot off for tuning, as I understand it the function is to regulate rpm drop when coming off the accelerator. pretty sure it went back on there OK though. ..

Sounds like your idle mixture or float level is still off a bit, too rich or too lean can cause a symptom like that.
_________________
Rust NEVER sleeps and stock never goes out of style.

Wanted, OG paint 1971 Niagara blue decklid.

Stop dead photo links! Post your photos to The Samba Gallery!
Back to top
View user's profile Send private message Gallery Classifieds Feedback
whatdoesthisbuttondo?
Samba Member


Joined: April 05, 2012
Posts: 225
Location: Victoria
whatdoesthisbuttondo? is offline 

PostPosted: Tue Jun 20, 2017 12:47 pm    Post subject: Re: Second Bus and First Engine Drop. Need guidance! Reply with quote

Quote:

whatdoesthisbuttondo? wrote:
1. Has a very hard time starting now when cold, cranks for ages and only idles at 500 until chokes open. we had adjusted the right choke a bit as it wasn't closing all the way- sticking with a quarter inch gap. ..

What starting procedure are you using?, I find 2-3 pumps of the throttle and let go then crank works best for me. The chokes shouldn't close fully unless it's ~0*C or colder, at room temperature there should still be ~ 1/4" gap after poking the throttle once to set them. Low idle could be too much choke (unless it dies instantly when you touch the gas), you may have to adjust the length of the high idle links a little to open the throttle plates a little more when the chokes are closed.


This could be it, ill re-set them and see if that fixes things. Typically i pump twice and crank, but right now having to pump and crank continually until it fires.


Quote:
2. when coming to a stop, rpms drop to 500 and then quickly climb back up again. We had the dashpot off for tuning, as I understand it the function is to regulate rpm drop when coming off the accelerator. pretty sure it went back on there OK though. ..

Sounds like your idle mixture or float level is still off a bit, too rich or too lean can cause a symptom like that.


Idle mixture an easy check, will reset and see. So I believe I should be on the Central Idle Circuit coming up to a stop, am I correct that the only adjustments I can really do to affect CIC are throttle plate position/ throttle stop, idle mixture, and idle speed? All hoses good, have vacuum, CIC solenoid working.

Quote:
1/16" pipe to hose connector


@Wildthings thank you, have you got a photo of this setup? Not familiar with the earlier carbs.
_________________
1973 Campervan. Stock 1700. Dual Solex carbs. Pertronix electronic points on distributor (stock, not a 009). Engine rebuilt in October 2016.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
senseless1707
Samba Member


Joined: June 03, 2017
Posts: 42
Location: Seattle, WA
senseless1707 is offline 

PostPosted: Tue Jun 20, 2017 2:39 pm    Post subject: Re: Second Bus and First Engine Drop. Need guidance! Reply with quote

Damn nice build. Was fun to read through it. Going to pull my engine out and do pretty much exactly what you did. Need to get her running and on the road. I am itching to drive it.
_________________
2014 VW GTI
1976 Westfalia Camper
Back to top
View user's profile Send private message Gallery Classifieds Feedback
busdaddy
Samba Member


Joined: February 12, 2004
Posts: 38240
Location: Surrey B.C. Canada, Land of the giant flying moose!
busdaddy is offline 

PostPosted: Tue Jun 20, 2017 4:32 pm    Post subject: Re: Second Bus and First Engine Drop. Need guidance! Reply with quote

whatdoesthisbuttondo? wrote:

This could be it, ill re-set them and see if that fixes things. Typically i pump twice and crank, but right now having to pump and crank continually until it fires.

Try a few experiments, for one hold the throttle open (no pumps, just hold it and don't let go) and see if it starts faster in the morning, next morning prime each carb with a tablespoon of gas down the throat before starting, you have to determine if the reluctance to fire is too much gas, or not enough. But save these until after you get the idle mix dialed in.

Quote:
Idle mixture an easy check, will reset and see. So I believe I should be on the Central Idle Circuit coming up to a stop, am I correct that the only adjustments I can really do to affect CIC are throttle plate position/ throttle stop, idle mixture, and idle speed? All hoses good, have vacuum, CIC solenoid working.

You should be on all 3 idle circuits at all times, I like to set up the carb base mix screws slightly on the lean side and make up the last ~.5% Co with the CIS. Set up each base screw (after balancing the linkage and stop screws with a snail or Unisyn) for best/fastest idle with the other carb's and the CIS' solenoid disconnected (2 cylinder idle), then with both carb solenoids but not the CIS' connected do equal turns on the stop screws to reach ~700RPM, then turn each mixture screw in equal turns (1/4 at a time) until you get a 50 -75 RPM drop, finally bring the RPM back up to 50 RPM above your final target with the CIS by playing with it's mix and volume screws for best idle/RPM and then lean it's mixture screw until you get a 50 RPM drop from it.
_________________
Rust NEVER sleeps and stock never goes out of style.

Wanted, OG paint 1971 Niagara blue decklid.

Stop dead photo links! Post your photos to The Samba Gallery!
Back to top
View user's profile Send private message Gallery Classifieds Feedback
whatdoesthisbuttondo?
Samba Member


Joined: April 05, 2012
Posts: 225
Location: Victoria
whatdoesthisbuttondo? is offline 

PostPosted: Wed Jun 21, 2017 12:40 pm    Post subject: Re: Second Bus and First Engine Drop. Need guidance! Reply with quote

Chokes an easy fix! Just readjusted to have a quarter inch gap cold. starts right up. Thanks.

Quote:
you should be on all 3 idle circuits at all times


By three idle circuits I think you mean

1. right carb, cylinders 1 + 2 lean
2. left carb, cylinders 3 + 4 lean
3. CIS rich

OK, makes sense that they should all be contributing varying degrees.

I tweaked the CIS mixture and reset idle speed and rpms drop much smoother now and were settling at 900. Amazing how big a difference such small adjustments can make. still popping a bit coming off the throttle on a downhill.

Haven't changed to the NGK plugs yet, they are about 2 mm longer than the bosch ones I have in and I want to check that they aren't going to get clipped by the pistons. hopefully will have the clearance. I checked the valve distance (see earlier in thread) but not the plugs.

Quote:
do equal turns on the stop screws to reach ~700RPM, then turn each mixture screw in equal turns (1/4 at a time) until you get a 50 -75 RPM drop, finally bring the RPM back up to 50 RPM above your final target with the CIS


Tuning mixture by RPM sounds easier than tuning using the mixture reference hose technique for CO in Colin's procedure.

(http://www.itinerant-air-cooled.com/viewtopic.php?t=7767)

Can you pls explain what you mean by "make up the last 0.5% Co"? I know Co is a way to measure of unburnt fuel in the exhaust, and so a richer mix means a higher CO, but not clear on what level of CO one would aim for and why.
_________________
1973 Campervan. Stock 1700. Dual Solex carbs. Pertronix electronic points on distributor (stock, not a 009). Engine rebuilt in October 2016.


Last edited by whatdoesthisbuttondo? on Wed Jun 21, 2017 1:09 pm; edited 1 time in total
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Display posts from previous:   
Reply to topic    Forum Index -> Bay Window Bus All times are Mountain Standard Time/Pacific Daylight Savings Time
Page: Previous  1, 2, 3, 4, 5, 6, 7, 8, 9, 10  Next
Page 9 of 10

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum

About | Help! | Advertise | Donate | Premium Membership | Privacy/Terms of Use | Contact Us | Site Map
Copyright © 1996-2016, Everett Barnes. All Rights Reserved.
Not affiliated with or sponsored by Volkswagen of America | Forum powered by phpBB