Originally Posted by
houston
Flush out hsn
And be sure to use an external fuel filter , screen type best
Originally Posted by
chopper82p
You sure you have good pinch? Like some have suggested, it may be a heat problem. Check for sleeve roundness when you have the piston in it. With just the piston and sleeve, slide it up and down and see how far the piston goes up the sleeve and report back.
If nobody can tune the engine, you have an issue with that engine. Maybe send it back to Novarossi and see if they can replace it? (make sure you have a c6tgc or c5tgc plug in there when you do send it back
)
Check the rear bearing. Does the inner race feel tight or is there some play? Rear bearing should be tight, if not, it needs to be replaced and thats likely your problem, if its loose.
Originally Posted by
chopper82p
Pretty sure if he has had lots of people trying to tune the engine, it can't be as simple as setting the HSN to flush, JMO.
Can't be a fuel delivery problem because it only is happening with his btt, his other engines are running fine.
The HSN is what we were thinking at the track actually. It is the only hting we have not checked and didnt have time to play with it anymore at ht etrack as I threw in another engine and raced. I tried the stock Mugen clutch, and a Werks clutch to no help. This motor is dialed as far as tune goes. It will idol all day and for 4 minutes it is super sharp and a strong top end it just flames after holding it full throttle about 4 minutes into the run.
I have taken it apart and clean as a whistle. It looks phenomenal. You can barely turn it over by hand and when hot it isn't much easier. Has a ton of pinch as the motor a few races ago only began to really wear in and run really well. Do not have time tonight but maybe it is the HSN. Done many tests and while puzzling it for sure is not clutch, fuel lines, fuel tank, or pipes. I will dig into it more tomorrow night.
The front bearing is brand new and passes bearing leak down test with flying colors. The rear bearing is perfectly smooth as butter. I know it is not bearings. Last resort is to take the carb completely apart.....