Partzilla Live Q&A with Garrett Sifford – November 20, 2020
John Talley was out racing during this Friday edition of Live Q&A, so Partzilla pro mechanic and recurring guest-host Garrett Sifford stepped in to take on your motorcycle and ATV repair questions.
Garrett answered questions about a wide range of topics, but ATV repair questions dominated this week’s session. Check out excerpts from Partzilla’s latest live Q&A session below, and tune into our YouTube and Facebook channels every Friday at 3pm Eastern for the next edition.
NOTE: We experienced some audio difficulties during the first half of the live stream.
Partzilla Live Q&A Highlights – ATV Repairs
ATV Carburetor Problem
I’ve been having a problem at the very bottom of this carburetor. There’s a little hole where the overflow goes and gas constantly leaks out. If I turn the screw to stop it, my ATV won’t start at all. Where do I need to start looking to get this thing fixed?
Garrett Sifford: If it’s constantly leaking gas out of the carburetor, my first thought is you have a stuck float bowl, and when you tighten that overflow valve it basically cuts off the fuel to the carburetor and floods it. So your first step would be to take off the carburetor and check the float seat and valve, and go ahead and give it a good rebuild while you’re in there. That’s more than likely what’s going to fix your problem.
ATV Engine Failure
How do you know when a 4-wheeler is going to blow up? I want to buy a used one.
Garrett Sifford: The only real way to tell … the life cycle of an engine is by doing a compression test on it. So if you have [a compression tester] laying around or you know somebody who has one, I think we have a video on YouTube showing how to do a compression test. That’s your best bet when buying a used engine, because that’s going to tell you how it’s been ridden and how much life is left on it.
ATV Valve Clearance
Can I check my ATV’s valve clearance with the cam chain off if I put the cams in time?
Garrett Sifford: Usually to check your valve clearances, you want the engine to be completely cold and you’ll need to have it set to top dead center on the intake side, and then when you go over to the exhaust side, you need to make sure it’s at top dead center on each bank of the engine. That’s the best way to check your clearances.
ATV Starting Problems
I have a 2002 Yamaha Grizzly 660 and every time I try to start it, it makes a grinding noise. I just changed the starter. Any thoughts?
Garrett Sifford: On those Grizzlys I know the starter actually goes into a one-way gear that spins on the flywheel. If it’s making a grinding noise and you’ve already replaced the starter, chances are it’s that one-way gear that you need to replace.
Want to see more live repair questions answered? See all of Partzilla’s Live Q&A sessions here.