Will to large of jets make engine overheat?

[steelkiwi75]

I have a pro systems carb. I can't find paperwork on it. Believe it's about a 800 to 850 cfm. Jets are 76 front and 86 back . Engine starts to overheat 5 or 6 laps into feature and is always hard to start. Sometimes i have to hold pedal to the floor til it fires. Any feedback? This is on a 358 sas spec aluminum head motor. Thanks in advance

[RacerX10]

I have a pro systems carb. I can't find paperwork on it. Believe it's about a 800 to 850 cfm. Jets are 76 front and 86 back . Engine starts to overheat 5 or 6 laps into feature and is always hard to start. Sometimes i have to hold pedal to the floor til it fires. Any feedback? This is on a 358 sas spec aluminum head motor. Thanks in advance

Usually too small a jet (lean condition) is what causes over heating. Where's your timing at ?

Vacuum leak could cause what you're talking about too, and would indicate as a lean condition (I think, I'm not an expert on such things). Have you gone over the carb really well looking for loose screws / bad gaskets / etc ?

[perfconn]

Sounds like you have two problems.Too large of a jet will make it run cooler.Having to hold acclerator on floor to start indicates it is flooding.The overheating is another problem and could be anything from dirty radiator,belts slipping on worn out pulleys,wrong fan,fan not in right position,could be lots of reason to overheat but not too big a jet.

[gbeem]

Make sure your squatters are squirting. Had this problem a few times.

[keeks]

There will be a number stamped on the side of your carb. Go to www.pro-system.com and click on the "Ask the carb guy" link. Post your carb number and Patrick will tell you what your original build is. Then he can point you in the right direction.

[TALON75]

Have you checked for retarded timing lately? The symptoms you describe would make me look there first. I would also take keeks advice, as I haven't ever seen jets that far off, could be the way it was built but if you can find out then that would be good piece of mind.

[let-r-eat]

I would double check valve adjustment, timing, and general tuneup items also.

[steelkiwi75]

No reply from pro systems yet. What would be y'alls suggestions on how much to lower jets?