Originally Posted by
maddog74
When you guys do the nitro cleaner test behind the flywheel of the motor do you take the flywheel off and clean all the dirt and debris off of the front bearing and then put the flywheel back on and do the nitro cleaner test. Seems like if you didnt then your motor would suck alot of that debris in. I have a Nova 4btt stock with almost 5 gallons on it still has good compression but when I get it up to temps and let it sit on the box to idle it will only stay idling for about 10 to 12 seconds and then shutoff. Put all new fuel lines in, fairly new tank, sealed up with lucky 7, checked clutch shoes and springs so everything looks good. When I am out on the track there are no problems does not flame out but if I let it sit for more than about 12 seconds it will shut off. Does it sound like I could have a bad front bearing I know there are alot of variables but I have been racing for a while now and it is not the tune plenty of smoke bottom to top and temps are in the 230-240 range. Any help would be appreciated. Oh yeah this is on a losi buggy with nova 2096/41021.
This sounds more like a tuning issue problem to me and not a leaky bearing. Your bearing would have to be completely shot to effect the idle, not just a bad seal. However, the problems would become astronomical while actually running on the track. I have never in 11 years heard of issues that only manifest at idle speed and then go away while running at race temps and RPM's. It sounds to me like you have a slight blockage somewhere which would be more noticeable at low rpm because there is less pressure. Once your pipe starts creating good pressure its enough to push the fuel through the blockage. Take your carb apart and flush it and clean it well with small toothpick or similar and then re-assemble and try again. first check your tune, it may be as simple as your idle gap being too small. It could also be your pipe has a oil clog.