76 HD D model

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Jamie

New Member
I have a '76 model D Harley.

It will run up to full RPM. But a few seconds later, it boggs down like it has lost all fuel flow. Pull the choke out half way and it picks RPM back up. Then a few seconds later it boggs down again.

I have checked the point gap about a dozen times. It's set at .022.

I have checked the timing about a dozen times. It's dead on. Both forward and reverse.

I have checked the spark plug about a dozen times.

I have replaced the fuel filter and all the fuel lines.

I rebuilt the carb (only once). I have reopened the carb and adjusted the inlet control lever properly.

I have checked for vacuum loss around the crankcase. I have checked for vacuum loss all along the side of the carb. No RPM increase or loss while doing this.

I sprayed carb cleaner in the air intake while engine running and starts to bog down. RPMs immediately increased.

I still have the bogging down problem. Anyone have any ideas? Oh yeah. I have good fuel in it.
 
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Jamie

New Member
No, I still have the problem.

I was doing some reading and found out that after rebuilding the cylinder most people get around 110psi of compression. I also found out that 80psi (FWD) and 85psi (REV) is normal. I have 60psi (FWD) and 75 (REV). So I think I'm gonna rebuild the cylinder. If that doesn't work, I am totally gonna replace the carb with new. My muffler is a piece of crap. So I intend to replace it. Maybe too little back pressure can cause too little vacuum. I don't know. I still have ideas, but they are running out rather quickly.

WHEN I do get this fixed you can bet that I will publish the results. I have read and read and read forums on several different golf cart sites and it seems either people don't want to share their knowledge or they just take off once they fix their problem. I have read about similar sounding issues all over the place, but never a solution.

Now I know, there are dozens of things that could cause this problem. I know this just by the mechanics I have talked to. But you would also think that with as long and as used as these forums are, all the possible causes would have been solved or at least mentioned by now.
 
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johnny9

New Member
i had this problem but only when i increased the air flow and put a header on it..
it would only let me give it a 1/4 throttle then bog down,,if i pulled the choke out while driving
it would go fine...it needed more fuel..i used my torch index drill bits(that hot rod recomended)
and drilled a step bigger and WOW..solved my problem..even drilled it 2 sizes bigger than the jet they
sell for high proformance carts that i just bought and its smaller than what i drilled by a tad.

cured all my problems and now it runs like a raped ape for a stock 295cc ezgo..
if it ran good before and you havent modified anything then this may not help you.
the ethanol in todays gas may be helping you problem in a older cart also,not sure thojohn
 
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Jamie

New Member
The jet we put in when we rebuilt the carb is a .039. Are you saying all I really need is a bigger jet? I have a .045 I took out of my Harley a few years back.
 
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johnny9

New Member
hey jamie..i wouldnt want to say thats your problem for sure but it was mine and i had the same problem when giveing it gas..it was real easy for me as i took the carb of a few times..mine is drilled bigger than what they sold me for it to getit right also..
since jets are cheap,,if you have another id try it if easy for you to do..
i used a (looks like a pen)torch tip drill bits that has about 8-10 diffrent bits in it..i took the jet that came out and stuck
a drill bit in the jet till i found the one that fit the jet i had..layed that bit to the side for refrence and used a bit that was 2 sizes bigger and drilled it by hand real easy with my fingers,blew it out and wow,it worked great.

you may only want to go one step at a time as you cant go smaller..
have you looked at your plugs to see if there rich or lean??better to start with new plugs after you drill it and drive it for a bit to get a good reading on the plugs afterwards..then the new plugs will help figureing out if you need to go richer or not.

hope this helps ,john
 
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Jamie

New Member
EXCELLENT! I have a .045 jet so I'll try that before I drill anything. But I also think it would be better to just buy a couple of jets that are bigger. Anyone have a source for jets for a Tillotson carb? Maybe I'll take the jet up to my local Napa. They do a lot of 2 stroke work there and I'm sure will be able to acquire me new jets. Thank you johnny9. You're being of great assistance to me.

Y'all are gonna have to bear with me a little on this time table for getting things done. My wife is already out of work and it looks like I am rapidly headed that way myself. So money will be tight for things other than food and mortgage. Plus I have a Harley to keep from being repossessed.
biggrin.gif
 
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johnny9

New Member
yeah things are slow here in fla also..but im getin the bills payed and workin on the golf cart a lot more.
dont let nothing happen to that harley now..you can kill food with your gun and use the harley to drive
there to kill the food,haha,john
 
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mikeyz300

New Member
Jamie i just had the same problem, it was the reed plate it had loosened up. try that let me know how you make out.
 
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