1976 Harley Gas Golf Cart Only Running in Reverse Probably Compression

CrtCrash

New Member
1976 Model D Harley Davidson gas golf cart only running in reverse probably compression?
experienced hard starts if at all, lots of choking as symptoms then finally too cantankerous to mess with driving it.

was running ok with some loss of power on hills
replaced reed valve, ran same to a bit better.
replaced belts ran a bit better

began to get really hard to start needed choke
replaced points/condenser that looked ok still same behavior
replaced carburetor (20$ cheapie) improved reverse running a lot.
replaced filter and fuel line at same time
ran strong to great in reverse almost no choke needed , will not start fwd, even after warming up with reverse running.
backfires though exhaust after load up from cranking in forward.
cleaned all electrical connections to improve starter speed

I need to compression test but im guessing im marginally good enough compression in reverse and not good enough in fwd.
engine has never been rebuilt

any other ideas to check besides compression and getting ready to do the top?
I believe starter speed is a bit faster in reverse but it should have enough to hit in fwd. I definitely have spark. Just looking to eliminate other variables will probably top end rebuild either way just want to cover anything I might be overlooking.

Thanks!
 

Nubs

Cartaholic - V.I.P.
Compression is one issue and it's very common for the crankshaft seals to go bad, the fact it runs better running in reverse tells me the ignition timing is off a bit:twocents:
 

Rstaley

New Member
I had one that I had similar problems with. It had a new piston, barrel, good compression and everything, but still would run very poorly in forward and pretty good in reverse. It ended up being that I hadn’t properly set the ignition timing correctly. The model I was working on had no service manual available for it. However, I did come up with a copy of the procedure for similar models and it was close enough. There was no advance mechanism on the one I was working on. You had to “split” the timing adjustment between forward and reverse rotation of the crankshaft, and with each change of the timing, the point gap had to be readjusted. I have scanned the only documentation I could find into 6 files that I have attached. Hope it helps you. If you need them in some other format (I’ve sent plain old JPG’s) let me know and I will ty again. Woops! I tried to send them but the software said the files were too big. Perhaps you could send me you email and I could send them that way, or maybe there is another way to send them that someone can let me know about.
 

Rstaley

New Member
I went ahead and posted the information about setting the timing on my website. Just click on my signature link here and it is the latest post entitled "Harley Davidson Timing".
 

Rstaley

New Member
Thanks for the reply. It is kind of coming back to me how I had to work with the procedure. You have to locate a hole in the case of the motor that you look through as you rotate the crankshaft until a mark on the flywheel lines up with the hole. You do this with both CW and CCW rotation of the crankshaft. At the point at which you can see the mark through the hole, you position the backing plate of the points to where the points break and then set the gap of the points to the specified size. The challenge is that when you repeat the process rotating the crankcase for the other direction, the mark won’t line up perfectly when the points break, so you have to readjust the plate again and of course, this changes the gap setting (because you changed the position of the plate). So you have to work back and forth (CW and CCW) until you reach a happy medium where the adjustments work for both directions. Sorry about the quality of the scanned procedures. They are copies of copies of copies, but they were all that I could come up with.
 

CrtCrash

New Member
I found the service manual online, I don't remember where exactly... I do understand the procedure, just not getting luck, I will try again later today but I do think compression or maybe even generator speed is another factor. I tried to attach manual but even zipped is 25mb, I will look for my link I found.
 

Rstaley

New Member
It's been so long since I worked on one of those that I don't remember what exactly the compression should be. As I recall, it's not a very high number. It seems to me that even with the new piston, rings, and barrel, the compression only came out around 100. Maybe some one can help us there. I'm sure you already know this, but it is normal for the compression on a worn engine to be higher in reverse than in forward. It has a different wear pattern on the rings, piston, and cylinder when the piston is pushing down coming over TDC in each direction of firing. Since there are less fires in reverse, it almost shows higher in a compression test.
 

HotRodCarts

Cartaholic
When you check the compression test it cranking the engine in both directions with the throttle wide open. The compression should be around 110 - 120 lbs. Like Rstaley said the compression will more than likely be higher in reverse. When the compression on the Harley engines gets in the 80-90 psi range they usually won't start.
 

Rstaley

New Member
Thanks HotRodCarts! I went back through my notes, and the one that I put the new rings, piston and barrel on came out about 117. The parts came as a set but, the piston was way too tight for the cylinder so I had to do some honing. I'm sure my fit was less than perfect.
 
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