You could be running at a different altitude, have you considered an oil cooler?

 

You could be running at a different altitude, have you considered an oil cooler?

No I havent , the dealer who sold me the head says I shouldnt need it, and he says the jetting should be fine, Im at 2000 ft here, he told me to dump the race fuel and run 91 , and try it

 

Yes, run pump gas

 

Did you drill out the oil passage when installing the pump? And for jetting you should be around a 95 main and somehting in the 30's for a pilot on that setup.

 

This is the last dumba** that needs to be giving jetting tips. ^^

 

Yeah, swap it back to pump gas, rejet it on the rich side, then go finish breaking it in. Once the rings have bedded in, and loosened up, it'll run cooler and you can jet it for power.

 

Did you drill out the oil passage when installing the pump? And for jetting you should be around a 95 main and somehting in the 30's for a pilot on that setup.

I drilled it out to 2mm, I had a regular 88 kit on it before with out the bigger head and it ran cool.

Does anyone know what make of jets fit in these 20mm shewney carbs??

 

TB should have a kit available.

 

it sounds lean which explains the motor getting so hot and plug being white. TB sells a kit for that carb which comes with six jets from 82-95 sizes for 10 bucks. But I think those are kehin jets so your motorcycle dealer should have them.

 

you should be running an oil cooler anyway when it gets cooler out you can take it off.

 

maybe you have the timing retarded one tooth

 

he would tell a huge difference if timing was off by one tooth... mine was off by one tooth and didnt run even decent...about half the power of a stock 50. Sounds like its just running real lean. Lean it out as much as you can on the carb with the air/fuel screw...that migh be enough to fix it if it isnt running that bad... and yah, they suggest running pump gas so that would be a good change too...

 

or maybe the johnson wire aint hooked up

 

leaded gas will turn your plug and exhaust white... what is leading you to believe is getting too hot?

 

after a couple quick runs the head and cylinder is sizzling hot,

reading is our friend

 

leaded gas turns my plug pink. I must be getting that colored lead?

 

reading is our friend

i saw that, but air cooled motors are sizzling hot after a few hard runs anyway... what i'm asking is if it's heat seizing, starting to bog out or melting things



i haven't seen any air cooled ( or water for that matter ) that you can touch it after making a few passes.



I"m just asking him to be more specific about why he thinks it's TOO hot

 

Is It Getting Oil To The Top End?

 

I don't know exactly how hot is too much. When ran hard both my 131 gpx and 88 get around 250 degrees on the right side of the cylinder and the head is around 200.

My 88 was getting extremely hot when I first put it together b/c the oil hole was blocked off and the top end was screaming for oil. I had to replace my cam on that one. I also tore it down and replaced rings, valve seals, and gaskets.

 

i haven't seen any air cooled ( or water for that matter ) that you can touch it after making a few passes.

well i rode my stock cfr50 for a good twenty minutes and felt the engine as we loaded it up and it wasnt all that hot.... just real warm. And i dont know what kind of water cooled engines you have been around but our, my dad and i's, bored sv take a good two laps around our local street track before it gets to hot to touch. not that any of this really matters... just saying...

 

well i rode my stock cfr50 for a good twenty minutes and felt the engine as we loaded it up and it wasnt all that hot.... just real warm. And i dont know what kind of water cooled engines you have been around but our, my dad and i's, bored sv take a good two laps around our local street track before it gets to hot to touch. not that any of this really matters... just saying...

i hear ya..there's more mass and a lager radiator to dissapate heat on a SV, but when you get into smaller engines there's less metal there and therfore it heats up faster. one reason teh stock crf might not have gotten as warm is the fact of having a cast iron cylinder taking longer to heat (witch is why cast iron is harder to weld)...plus the smaller combustion charge taking place inside



as for water cooled engines i've been around.. i grew up racing 80cc 2 smokes, then off to 125 and 250 classes and those buggers got hot fast when you beat on them... i'm not argueing with you by any means, jsut trying to state that different masses of different metals will heat and cool at different rates...and aluminum heats up FAST..wich is the metal used in the 88 kit jug and head...it could be too lean, and it could be starving for oil.. only inspection adn time will tell///my suggestion is to go to harbor freight and get a infrared heat gun adn measure temps on the motor after running it and compare to other bikes of the same build... my 88 can barely be touched after the first 10 minutes of riding unless you want to loose skin, and it's been perfectly tuned ona a 5 gas wide band exhaust analizer... no oil cooler by the way either

 

I have an overheating problem as well, except my bike starts bogging and backfiring and then will quit. I was running on the blacktop heading to the next trail head. I was basically all out for about 15 minutes. It then lost power and started running really rough. If it sits and cools down it will idle fine, but as soon as you try to accelerate it is back to the same problem. After sitting for about 30 minutes it will run for about 5 minutes like normal and then back to the same problem. Should I be running a cooler plug? I am still running a "6." Maybe drop to a 5? Could I have burned out my CDI box? I have been searching around but have not found much help. TB 88 w/ RH. Help.

 

bump, need some help please



head gasket?? I am doing a compression test tomorrow.

 

Wrong way on the plug! Bigger is colder on NGK. I'd be looking to an 8 for higher speed pounding.

 

Get a temp strip before you jump to the assumption that is running too hot. As glenn said some race fuels will have a white plug reading whether it is lean rich or perfect. Do you think that it is running correctly as it stands now?