1989 Par Car Fuel Issue

[tew45]

Try the .010 piston set and it should run good. It looks good it should sell good.

[backyard]

Just to clarify, the way Tew measures his clearance with a feeler gauge is if he can stick a 0.010" gauge between the piston skirt and bore, then he has 0.010" clearance, not 0.005" or 0.020". The feeler gauge has to be bent in a curve shape to match the bore wall to get an accurate reading.

The 89 service manual says the engine has a bore of 2.75". So a stock piston should measure 2.745" and the following oversizes should apply.
0.010" bore 2.76" piston 2.755"
0.020" bore 2.77" piston 2.765"
0.030" bore 2.78" piston 2.775"
0.040" bore 2.79" piston 2.785"
and so on.

But it doesn't apply for reasons unbeknown to me. Look here at the pistons:http://www.discountcartparts.com/ind...and-ring-sets/
0.010" oversize piston is 2.746" which means a bore of 2.751"
0.020" oversize piston is 2.760" which means a bore of 2.765"
0.030" oversize piston is 2.766" which means a bore of 2.771"
0.040" oversize piston is 2.775" which means a bore of 2.780"

Now you know what the bore size is going to be, depending on which piston you have to use. Make sure you get the specs of the oversize pistons since they may not all be the same size from different sellers. If you take the jug to a machine shop they will need this info to bore out the jug so the piston will fit within specs. Sometimes it will need to be bored 0.030" over and the jug didn't look like it was wore that much and you're sitting there with a smaller piston that is now useless.

Something else to consider is the piston is pretty much laying on its side. This means when the bore wears down it will actually wear in an oblong shape instead of wearing round. Measuring in different areas around the jug with a micometer will verify this. The biggest size that you measure is going to be the minimum size of the bore.

[tew45]

That is the one. I usually get them from Dennis Kirk and water sports. The prices are probably competitive so the choice is yours to make. Good luck!

[Abomb55076]

So I replaced the piston and made sure to check the end gap of the rings install them in the correct orientation as well as make sure the piston was in the correct orientation when I installed it. Wiped some oil over the rings and piston before installing and put a drop in the cylinder after installation as well. Put it all back together and it sounds much better and fired once but still can't get it to run. Took the exhaust pipe off and there's definitely gas vapor coming out of he exhaust so I know it's getting gas. Sparks good. What else could be my issue?? Too much gas? There's a lot of gas coming out of the intake side of the carb when crank it over

[tew45]

Re-check compression. I know! but still check it. Could be flooding or timing (I don't know how a 89 HD times so flooding could be an issue. Try a new plug the old one may be bridged or fouled.

[Abomb55076]

It was flooding

[Abomb55076]

See video

[Abomb55076]

Originally Posted by Abomb55076

See video

https://vimeo.com/181398838