Starter overheating while on engine test stand (v.w. aircooled).

[Buick35]

I'm still trying to set the carbs. and fine tune my son's 69 v.w. engine.When it starts it sounds pretty good except that I can't seem to get it to idle down past 1800 or so. I think maybe because I adjusted the linkage (dual carbs.)to the wide open stop. Anyway I've tried two starters while trying to turn the engine they get so hot I think they're draging or binding up and won t turn the engine.It's got a new battery that I keep fully charged.I'll try to start it in the morning after it cools overnight. I hope I don't need a high torque starter.Could the compression be too high for the starter? Getting frustated,Thanks for any suggestions.Greg

[Frank DuVal]

Timing advanced? This can cause starter drag as the piston gets shoved back against the starter force, causing overheating of the starter.

Edited June 20, 2023 by Frank DuVal (see edit history)

[edinmass]

Sounds like a large vacuum leak……..it would cause the high idle, and the lean condition would cause overheating. It’s easy to ruin the new motor that way from what you are describing. Don’t run it, figure it out. Or you will melt a valve or piston,

[Buick35]

Thanks,I just tried it after sitting overnight and started fine.I checked for vacuum leaks and couldn't find any.I just timed it by ear to where it was running best but I'll have to check that again. I adjusted the idle/mixture screws and I don't think it's running too lean,in fact I pulled the plugs to check them and the ones on the left side had a lot of carbon on them so I set the mixture screw again. I'll recheck the timing and plugs. I might take it to a v.w.shop and have it checked out.Greg

[JACK M]

I do this initial work with a vacuum gauge.

[Rusty_OToole]

Do you know how to set the timing? Line up the notch on the pulley with the seam in the crankcase. Put a cigarette paper between the points. Slowly turn the distributor until the points start to open and the paper comes free. Or you can set them with a 12V test light. #1 fires at TDC.

 

To adjust carbs disconnect the throttle linkage adjust mixture, adjust speed, adjust mixture again if necessary, balance carbs. After the carbs are adjusted, adjust the linkage to suit.

[Buick35]

ThanksI

[m-mman]

I am sensing TWO different issues. 

Yes, you are talking about the carbs etc, but all that stuff only matters when it is running. . . . 

 

The title of your posting is describing a HOT STARTER MOTOR, not an engine that is getting hot or having trouble starting. 

 

1. How long are you cranking this thing? Cranking should only last about 30 seconds (maybe 60 seconds max) If an engine doesnt fire in that time, (and 30 seconds IS a very long time) Stop cranking and examine other issues. 

 

2. This engine is on a test stand. If a starter motor is not well connected in the circuit (good battery, good bolted connections including ground) then it WILL draw a lot of current (amps) and current is heat. 

 

Combining or superimposing problems will make diagnosis much harder. 

Edited June 22, 2023 by m-mman (see edit history)

[TOM H. S.]

May also want to use a leaf blower over the air cooling cylinders to prevent excessive heat buildup. Could also attach some Heat Sink vents onto the starter until all the issues are resolved. May also try using a Lead additive to your fuel since this all gasoline is Lead free these days. If you are using headers vs standard Heat Exchangers you may not have enough back pressure. Also check the Heat riser from exhaust pipes to make sure air flows through it. Just tid bits of info I've learned 40 years ago as a VW Bug owner and tinkerer. Best Wishes

[Buick35]

Thanks.

[60FlatTop]

On 6/20/2023 at 8:01 AM, Buick35 said:

,I just tried it after sitting overnight and started fine

That is one indication that your breaker point plate may be sticking or not lubricated after restoring the distributor. It will creep back slowly after the engine is shut off and have too much advance for a quick restart.

 

The classic example is "My car starts right up in the morning fine. Then I stop at the gas station and when I try to restart  it just grunts like the battery is low. Sometimes I walk home and when I come back it starts right up."

[Buick35]

Thanks, I thought I lived it good when I put it together but maybe it's sticking.I'll go out and try to start it again after sitting all day. Can I lubricate it without taking it apart?

[Frank DuVal]

12 hours ago, TOM H. S. said:

May also try using a Lead additive to your fuel since this all gasoline is Lead free these days

Doesn't the VW have steel valve seats like a Corvair? If so, no need for lead! Ever!

[Buick35]

Good to know.The starter issue seems o.k. for now but now I've got popping in the right carburetor.I'm thinking either mixture of timing but it will get figured out. I checked for air leaks but maybe I missed one.