96 G14 gets smoking hot then loses power

[ecaldwell78]

Hey Rib, thanks for looking! I didnt' even think to check the fins for obstructions/crud, but sure will. I will also read the plug. The only way i've tested for spark is with an inline spark tester, and even when it's so hot it wont fire, the spark tester still lights up. that's why my first theory of a bad ignitor kinda fell by the wayside. crazy thing is that it does run like a champ...just not for long!

[SandbaggerYDRA]

Originally Posted by ecaldwell78

Hey Rib, thanks for looking! I didnt' even think to check the fins for obstructions/crud, but sure will. I will also read the plug. The only way i've tested for spark is with an inline spark tester, and even when it's so hot it wont fire, the spark tester still lights up. that's why my first theory of a bad ignitor kinda fell by the wayside. crazy thing is that it does run like a champ...just not for long!

It almost sounds like the engine is getting so hot that the valves and lifters are expanding so much that they are holding the valves open which kills compression and power. You need to fix the cooling problem (Some critter might have built a nest in the cooling shroud), then check your valve gap. .008 warm should be the correct setting.

[sho305]

I did mine after it leaked oil it would lose power. Used a screwdriver and can of brake clean spray. It was plugged in areas. Might be the exhaust valve warping too.

[ecaldwell78]

Well guys, those cooling fins were PACKED with all kinds of crud! I spent hours cleaning it. One new thing i noticed, and am not sure if it's a big deal or not, but when i took the line from the fuel pump off the carb, if i held it low, it would keep pouring fuel out, key off of course. Last time i took the carb off to clean it, that didnt happen. Anyway, i got it all cleaned up and put back together, and took it around my block about 10 times at close to full out the whole way. never lost power but i decided to pull back into the shop to see how hot it was and the only thing still smoking was the muffler. Not smoking out the tailpipe, just smoking off the body of the muffler because of heat. not knowing much about yammis, does the muffler usually get that hot? everything else didnt' seem as hot as last time. i still need to check the valve adjustment too.

[Mike Mac]

Great news!! Just make sure the valve cover gasket isn't leaking!!

After it's healthy, you want to run it hard and hot, for a long time. Want to burn all that oil resadue out and off of that thing!

I would replace the 2 intake gaskets as well as the exhaust gasket, when you replace the valve cover gasket!!

[ecaldwell78]

I really can't thank you enough Mike! The kid keeps calling from vacation to check progress, so it was nice to tell him I'm close. I know mufflers get pretty hot, but is it common for them to smoke after a good long run? Being a 4 stroke not much should be built up in there like my old 2 strokes.

[Mike Mac]

Yes , normal!! They hold a lot of heat!! A Plowmans muffler is suppose to run cooler. But it is low restriction!!

[ecaldwell78]

That's great, thanks again Mike! Looks like a valve adjust, fresh oil, and cleaning the fuel pump just for the heck of it, and i'll be playing NASCAR for a few miles just to be sure it stays running like a top!

[Mike Mac]

Please change those gaskets, old gaskets get hard and brittle, making them not want to seal unless they are torqued tight. New ones seal well with less torque. Run the chance of breaking the plastic intake manifold spacer with old gaskets!!

Yes, valves at .004 cold!!

Good luck!! And, now we want pictures!!

[ecaldwell78]

Well unfortunately there's good and bad news. The good news is the engine now runs fantastic. The bad news is that under load it still loses power. Not an engine problem, but a power transfer problem. Belt is a little worn but nothing terrible. sounds like marbles in the rear. i pulled the diff plug and the fluid is milky and thin. Obviously that will be replaced and gears inspected. still great pulling power for about 1/4-3/4 mile but then the engine becomes really taxed to the point the cart only moves about 3-4 mph. i'm beginning to wonder why we got such a great deal on this cart!