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Sun Apr 03, 2016 6:23 am

My 34 pict 3 is leaning badly on acceleration at half or more throttle. If you ease Into it, it will go but if you want to take off quickly, it falls on its face and and wont Rev. I've checked the timing and it runs better really really advance. But that's not good for the motor and low on power (but no stumbles). I've cleaned the carb many times to no avail. Who can help?

Carb is on what appears to be a stock 1600 in my bug.

Sun Apr 03, 2016 7:11 am

What distributor are you running?

Sun Apr 03, 2016 7:41 am

009. If I keep the choke butterfly shut, it runs fine. I may just spring for a new carb

Sun Apr 03, 2016 8:26 am

Have you ever considered that the problem may be due to you trying to use one of those shitty 009 distributors in combination with a 34 pict-3 ?

Sun Apr 03, 2016 8:39 am

Sounds like you got the lean recipe right there using an 009 with poor advance ie. no vacuum along with a 34 pict 3 sensitive to advancing. Springing for a new carb may not change anything especially if jetting is the same. I would do the simple things first one step at a time.

Pull the Main jet, if it's a standard 127 size try a 130 and see how it runs, more fuel will also let you run more timing without pinging. The 009 runs better at more timing not because it's running good but because it's compensating for all its flaws.

Next you can lower the Air jet size alittle if you still want to richen it up but don't go too rich on both Main and Air or you will be washing oil off the cylinder walls and shortening motor life. Good luck!

Sun Apr 03, 2016 8:45 am

It ran great a month ago. I needed to pull the motor for something and it didn't run right after it was re-installed. I've rebuilt the carb and blown it out many times. My guess is there is a blockage in the power jet circuit that won't come out with carb spray.

Sun Apr 03, 2016 8:49 am

I've never had a problem running a 009 and a 34 and I have tuned many engines with that combo when I worked at an ACVW shop in the 90s. People have been doing it for decades. You may have to play with the accelerator pump adjustment to find the sweet spot but if the carb is good you will be able to tune out your hesitation. Make sure the discharge nozzle is aimed correctly so the fuel forms a fan and atomizes properly. I'd it just sprays straight down that will cause a huge flat spot.

brad

Sun Apr 03, 2016 4:00 pm

I have run 009s for a long time also, but the PICT 34 and 009 combo are very tricky to make run well together. It takes a lot of fiddling to get out the flat spot, and the slightest change in timing or carb adjustment can make it go from OK to almost undriveable.

Sun Apr 03, 2016 4:42 pm

taylorb1 wrote: My 34 pict 3 is leaning badly on acceleration at half or more throttle. If you ease Into it, it will go but if you want to take off quickly, it falls on its face and and wont Rev. I've checked the timing and it runs better really really advance. But that's not good for the motor and low on power (but no stumbles). I've cleaned the carb many times to no avail. Who can help?

Carb is on what appears to be a stock 1600 in my bug.

This condition is caused by your accelerator pump. Did you change that diaphragm? Did you mess with the adjustment of the accelerator pump linkage? When you assembled the carb, did you check to see if the spray nozzle was pushing a good, solid stream of fuel when you pulled the throttle?

There are two check valves in that circuit. One is in the fuel bowl and you have to remove a plug to get the BB out of it. Most of the times, they are ok if the carbs been in use. I always remove the plugs and remove the BB's before dunking the carb body in my ultra sonic cleaner.

If I were you, I'd pull the throttle and see if I'm getting a solid stream of fuel out of that brass nozzle. Also, make sure the stream of fuel is hitting between the body of the carb and the butterfly.

Sun Apr 03, 2016 5:04 pm

wcfvw69 wrote: taylorb1 wrote: My 34 pict 3 is leaning badly on acceleration at half or more throttle. If you ease Into it, it will go but if you want to take off quickly, it falls on its face and and wont Rev. I've checked the timing and it runs better really really advance. But that's not good for the motor and low on power (but no stumbles). I've cleaned the carb many times to no avail. Who can help?

Carb is on what appears to be a stock 1600 in my bug.

This condition is caused by your accelerator pump. Did you change that diaphragm? Did you mess with the adjustment of the accelerator pump linkage? When you assembled the carb, did you check to see if the spray nozzle was pushing a good, solid stream of fuel when you pulled the throttle?

There are two check valves in that circuit. One is in the fuel bowl and you have to remove a plug to get the BB out of it. Most of the times, they are ok if the carbs been in use. I always remove the plugs and remove the BB's before dunking the carb body in my ultra sonic cleaner.

If I were you, I'd pull the throttle and see if I'm getting a solid stream of fuel out of that brass nozzle. Also, make sure the stream of fuel is hitting between the body of the carb and the butterfly.

This. On all points.

Also, one tip I read ages back: install the accel pump cover somewhat loosely, maybe one full turn loose on each screw. Then open the throttle all the way, and while holding it there, tighten the scores of the pump cover. This ensures the diaphragm is not overstretched at full throttle, making it last longer and giving a more consistent injection.