Honda TRX ATV Forum banner

1 - 6 of 6 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter · #1 ·
First-time poster here, so sorry in advance if this post is in the wrong place!

So my 300ex was running fine a few weeks ago, and I was warming it up when all of the sudden it started sounding really bad (similar to bogging noise). I investigated the intake system and found nothing. The next day it would not run at all.

A friend who has a lot more experience than me took a look at the carb and intake system and found no issues. He said it might be a problem with the valves but he wouldn't be able to do anything about them because he forgot his feeler gauges. BTW: the carb I had was a Chinese one, it had worked great prior to this, but I decided to get an OEM one anyway (more on this later).

I adjusted the valves to the best of my ability... the intake valve is adjusted to specifications, but the exhaust is 'loose' as I was unable to adjust it due to the tappet screws not turning. After adjusting the intake valves, though, it finally ran. However, it would not idle and it would bog severely at medium to full throttle.

Today, I put on the OEM carb and I had the same exact issue... it ran but couldn't idle and it had the same bogging issues. So, I don't think it's the carb.

TL;DR: My question is, can improperly adjusted valves cause severe bogging?

-Thanks
 

·
Super Moderator
Joined
·
4,250 Posts
Based on how far the tappet screws are screwed into the lock nuts, I'm going to guess you have a bad cam and rocker arms - no lift on the exhaust valves.
 

·
Registered
Joined
·
3 Posts
Discussion Starter · #5 ·
Yes, the tappet screws would not adjust.. I think either the screws or nuts are stripped. I readjusted the intake valves but nothing changed. Do you think it would be worth it to see if the cam/ cam chain is in the correct position?
 

·
Super Moderator
Joined
·
4,250 Posts
No - checking the cam and cam chain only has to do with valve timing - the timing of the cam and valves does not have anything to do with lift - lift has to do with the height of the cam lobes - you need to get the top cover off the engine to see the camshaft - my guess is the exhaust lobe and the rocker arm are severely worn and the exhaust valves are only just barely opening.
 
1 - 6 of 6 Posts
Top