thomas james
New member
My box stock is running a Lil hot. What size jet should I run if I'm wanting to rum around 5800-6000.
Not that I disagree with you in any way, just wondering why this engine uses such a small jet compared to what I’ve seen in most posts?29-31 should be fine,stock air filter wont let you run much bigger of a jet than that. if temps are too hot lower your timing
Not that I disagree with you in any way, just wondering why this engine uses such a small jet compared to what I’ve seen in most posts?
I see .039” recommended all the time. I’m guessing this must be a different type of engine or carb or something and I would just like to know what the difference is.
Comments, compliments, criticisms and questions always welcome.
He is running a stock air filter, it wont use as much jet as an aftermarket air filter adapter/filter.
Well, like my SIG says; if the data doesn’t match the theory, get a new theory. If that engine can reach 6000 RPM, with anywhere near the right gear ratio, it must be getting enough air. I could be wrong, but I sure would like to see comparisons of the two on a dyno.I honestly dont see how the stock airbox even breathes enough air for the engine to run when used for racing, but it somehow does and works.
I'm still trying to figure this out. Just curious, how much difference is there in gear ratio between a filter and the stock airbox?A 31 main jet and 19 low jet works perfect with small pipe and stock air box.any bigger jetting and it will flood out. Shoot for 5800 to 6000 rpm with 6000 if running a small bull ring.
I honestly dont see how the stock airbox even breathes enough air for the engine to run when used for racing, but it somehow does and works.
The stock air box is like a restricter plate. If you take the 3 litle screws out under the filter and lift the top off and look down in there you will see just how small the hole for airflow there is. If your aloud to modified the air box then take a dreamil and start reaming. Take the filter paper out of the filter and just use the outer foam filter with light oil on it. Then you can go to a 34 jet.I'm still trying to figure this out. Just curious, how much difference is there in gear ratio between a filter and the stock airbox?