• Valve guide.

  • If you've got some feedback for me but aren't ready to write a review, here's the place to voice your concern or comments. I'll also post explanations of the policies that help our programs function. -T@BD
If you've got some feedback for me but aren't ready to write a review, here's the place to voice your concern or comments. I'll also post explanations of the policies that help our programs function. -T@BD
 #12675  by JasonB
 Mon Aug 13, 2018 8:34 am
Got a new 175cc gy6 motor and my exhaust valve guide has come unseated. From past experiences it will just come out again when it gets to operating temps. Any tricks to reseat? Also the main reason this happens is due to an overheated head. Brand new motor, carb....etc. why is it getting hot enough to cause me to probably have to get a new head?
 #12676  by CheethaSpeed
 Mon Aug 13, 2018 10:16 am
Couple things come to mind:

Low spark, valve adjustment, air/fuel ratio, exhaust leak, restricted exhaust

More serious issues: bad cam, head gasket, cracked head

My thoughts as possible causes

How does it run?
 #12677  by TravisXBD
 Mon Aug 13, 2018 10:30 am
Dropped valves on the GY6 on a new engine aren't related to heat. It would be an out of spec guide from the factory, a defective head. This is the second time I've dealt with this. The first was on my brand new lime green Yerf Dog GX150 over a decade ago. If the guide is undersized, it will pop out of place after the first few heat cycles. I believe you've encountered the same thing. It's not due to overheating.

Heat issues on GY6's come down to overly lean jetting which wouldn't be covered under warranty. And - please believe me. I'm advising against what's most convenient for me by saying it's not a heat issue. Other places would just go with the overheat idea and try to blame it on your jetting or something else you're doing. I think the problem is in the part itself, and I'd like to handle it under warranty.

Jason, since you're already inside the engine I think the best course of action is to ship out a new head to you. Are you Ok with performing the reassembly? I have two guides that'll help with the process:

Easy GY6 Cam Timing Guide
https://www.buggydepot.com/tech-center/ ... enter-tdc/

GY6 Valve Adjustment Guide
https://www.buggydepot.com/tech-center/ ... y6-valves/
 #12678  by JasonB
 Mon Aug 13, 2018 11:30 am
Yea!! I don't mind reassembling. And I was thinking the mixture was running to lean. As far as how it ran..... when I drove it, no problems had good power etc. But ya Travis, I am about to go ahead and order a few more things, so let sammy know what I need as far as a new head. I am going to run my old carb till I get time to figure this new one out. Ty all.