Bn-4 heater step by step

[man130]

Alex, I took a small plastic soda bottle filled with gas and hung it on hood to keep it higher then pump,I had pump unbolted and sitting inside the hood area to work on it.Then I un hooked hose from pump till gas came out then stuck hose quickly unto pump (primed it basicly)then tapped 12volt source till the gas came out .Might want to try it that way to take out all other variables like tank hoses clogged whatever if it dont work this way it dont work. It should not make a stream of gas just a little spit with each touch of power.After you get it working you can hook it up right and measure how much gas its acually pumping. forgot off top of my head how much its suppose to pump. If I remember I pulled both ends off pump and soaked it in penatrateing oil for a little while and cleaned out what I could,not much in there really to ness with. good luck

[Worknclassbug]

I agree with the above. Mine was doing the same when I first got it clicking but my trouble was the check valve in the pump was stuck open so whatever fuel it was pumping it was sucking right back into the pump when the piston returned. A good soak in penetrating lube freed it up. But like what was said above, I would verify that the pump is actually getting fuel. There is a filter between the tank and the pump. Mine was pretty nasty. Take the fuel line off that feeds the pump and make sure you are getting fuel to it. If you are checking for fuel at the heater it takes a long time for the fuel to get there if the pump is dry. Every time the pump clicks it only pumps around a drop of fuel so it takes forever for gas to get up to the heater if the line is dry. Good luck.
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73 Thing
71 Karmann Ghia (2.2L Subaru Conversion)
72 Deluxe Transporter
Huntington WV
Member of The Wagenfolks

[duderman]

Last Friday night my BN-4 started running rich. I went threw it last winter and installed it in the spring. I've been using it almost daily and love it. I pulled it Saterday night and found that the motor had run dry and slowed enough to make it not burn clean. Before I install my other motor I would like to oil it, greese it, lube it, whatever. My question is: Do they need to be maintained? What would be a good lube so I don't have this problem again? It will take me a few days to get both heaters apart so I'll be checkin in. Awsume thread. I hope it's still alive. Thx.

[Solomon Grundy]

In my vast amount of skill and stupidity I managed to break the grounding screw on the motor housing.
It all started when I was inspired to find out why my fuel pump on my BN4 decided to stop working 8 months ago. Per this below post. “Heater (fuel pump) question”
http://www.thesamba.com/vw/forum/viewtopic.php?t=3...p;start=20
After trying some similar procedures I discovered the pump would work as long as I had the spark plug disconnected. This also worked in reveres so I surmised perhaps I too needed to check and clean my points. This would be a new adventure being I never had the BN4 fully dismantled…
A long around step “8. Remove the screw holding the brown ground wire to the motor housing.” I broke the screw off in the motor housing… BLAST!
I believe this unit has never been disassembled so you can imagine everything is very had to take apart.
Now I need to know something before I really screw it all up.
Can I still proceed to step “9. Give it a tap and the motor assembly will come out of the housing:” without destroying the unit?
I have tried to tap it out but it is well stuck from all these years of being used.
Where should I apply the force if I can in fact tap it out with the grounding screw still in?

[Russ5000]

Hi, you have really made it very easy to understand how the heater works, thank you very much for that. My heater also does not heat, my first question is if the reset switch is tripped will the fan still work or should it not come on.
Thank you,
Russ

[sobeity]

thanks every one on here! just got my heater going after two months of trying everything on here...thank you all so much!

it's hot in my thing...frickin stoked, WHOO!

[Captain Spalding]

Congratulations! Feels good, doesn't it? Remember to use the heater often to keep everything working.

Oh. And welcome to the forum!

[sobeity]

it DOES feel good...chicken skin good...i learned the last few months to keep a thing going good its best to use it, it likes to be driven and used otherwise its all goes to poop...i let mine sit for the last couple years while traveling around...not such a good idea...last two months been workin on it...heater has never been used,,,i'm the third owner of this one...father to son to me...son says they never used the heaters in any of their things...couldn't get them to work...knowing that secret safety switch on the back is a big help...

[sobeity]

i do have a question? the hose that connects the oil bath air cleaner to the carb is not there and there is a cap on the carb. do i need that vacuum hose there?

[memphisthing73]

Found this page. Seems to have full manuals for BN4 (in English)

http://oacdp.org/ebersp.html
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'72 Beetle
'73 Thing

[Wildthings]

I am being defeated on getting the small set screw holding the inner fan out. I have broken or bent every allen wrench that I have of the correct size. Have soaked the screw well with several different sprays. Thinking that it might be time to try heat. Somewhere I have one of those tiny butane torches so will try that. Guess I should make some form of heat shield to go between the fan and the cavity underneath it.

Thoughts?

[man130]

I guess soak and heat as you suggested, if that fails I guess your gonna have to drill out the allen bolt and if you must maybe tap one size bigger if you mess up the threads drilling it out good luck

[Wildthings]

Heat worked, I couldn't find my little Butane torch so I used the oxy-act rig with the smallest tip I have. Made a heat shield that fit between the impeller and the housing and gave it a few seconds of heat against the hub. Came free very easy.

What someone needs to do is come up with an electronic pulse generator for both the pump and ignition points. They electronics could just sit up under a cover on top of the unit with all the rest of the controls so would be easy to access. I wonder what is used on newer heaters?

[dekdiver]

I hope this post is still being looked at. There is some great information here. I do have some problems that I am not seeing an answer to.

For the most part, I don't have any problems getting my heater going. However, if my temperature nob is pulled out too far, my safety switch will trip. I have also noticed that it tends to trip more often these days even if I don't have the temp nob pulled out too far.

Has anybody experienced this and can I make any adjustments or clean something to keep this from happening?

Thanks

[vwwestyman]

I have my heater torn apart. I followed the flowsheet to determine that the fuel pump wasn't receiving the signal from the points.

Got it all apart to reveal the points on both ends of the fan. Both were pretty dirty, a little corroded, and there is a lot of very fine dust inside the caps!

I was just curious about the best way to clean all that up? (I'm thinking contact cleaner should do fine.)

Also, what would be best to lube up the gear for the fuel pump points?

And while I'm in there, can I somehow lube the bearings of the fan? When I initially got it to run, it was making some bad noises but it quieted down. It sounds much better but is still a little noisy.
_________________
Dave Cook

President, Wild Westerner Club

1978 Champagne Edition Westy, repowered to '97 Jetta TDI
1973 Wild Westerner
My Thing

[ente_kaefer]

Great thread !! I am going to assume I will be referring to it once I can locate a complete BN4 to install into my 1973 Thing . . .

[Pbotsonis]

[vwwestyman]

Got the heater back in the Thing!

I ended up using white grease on the gear, and some silicone lube on the rubbing block for the other points. I attempted to dribble some silicone down into the motor bearings by the shaft though I don't know how much really made it down in there.

Since I couldn't easily find the info in the thread, I'll say that the point gap I used on both ends was .018. I used a metal nail file to clean them up, and hosed the whole area down with contact cleaner before lubing.

When I first tried to fire it up, the pump still didn't run. But just to see if it would fire up anyway, I clipped a jumper wire from the wire that is controlled by the points, and grounded it at roughly 3/second as I saw was the rate.

The heater fired up pretty quickly doing that. After a couple minutes, I quit manually working the pump and it was going on its own. I have no idea what the initial problem was, but that worked.

I let it sit there and run for a while, and the thermostat was cutting the pump in and out properly and all that. Also it times out after the heater is switched off properly.

I still have no windows or roof, but having some heat will take a little edge off during the mornings for now.
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Dave Cook

President, Wild Westerner Club

1978 Champagne Edition Westy, repowered to '97 Jetta TDI
1973 Wild Westerner
My Thing

[notchboy]

Link

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[kenj06]

notchboy,
that is what actually inspired me to get my BN4 running.

Saved myself some money by knocking on the fuel pump to get it working and repaired my thermostat
http://www.thesamba.com/vw/forum/viewtopic.php?p=6956473

For anyone working on the BN4 be sure to check the sticky:
http://www.thesamba.com/vw/forum/viewtopic.php?t=332848
priceless info here