So just replaced a crankcase cover on the motor, honed the cylinder and put new rings on it. Adjusted the valves to .006 and now I have a tapping noise mostly after when you rev it up. It's not really if any ticky or knocky on idle or if you hold the throttle 1/2 but when you let off it makes the noise. If checked things and made sure my valves where set and everything was tight but havent found nothing. My cam chain was pretty hard to get on and seemed pretty tight so I dont think that's it. Noise sounds like it's coming from the top end. Any ideas would help. Thank you!
BigChubs
Did you check and clean the oil passages in the valve head? Was the rubber in ring in place? When opened it up the second time was it wet?
Yea there is plenty of oil up there and your talking about the oring on top by the rocker arms?
Yes that I ring. Only other thing I can Think of is something wore out or out of spec in tappet area.
Yea I lapped the valves and put new seals in and cleaned carbon off. And I've never owned the rancher with it running. I bought it with the motor out of it with a broken shift shaft. Also the left crankcase head bolt was broke off in there. I took apart the whole thing and replaced the casing with a new casing and put it all back together. I had a parts bike with another motor I used the head off of since it looked better then the one on the original motor. At TDC my rockers wiggle and have a gap of .006
That sucks, not having the history. I would dig out my inside/ outside measuring tools and have at it comparing with the shop manual. If you don't have a shop manual Its available on the manualslib app.
Some pictures, from what I can see and measured everything seems to be in spec. Imal about to remove the valve springs and check the wiggle in the valve guide.
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answer: the valve spring seat on one of the valves is lose in the head, sitting under the valve when warmed up, beating itself between the bottom of valve, and the valve seat. bottom line: valve seat is defective from the factory on these trx350 ranchers.
You sir need a prize. Of all things I never thought to actually try and see if I could pull one out. And sure enough I messed with it and it was able to come out (didnt just fall but loose enough to get out). So is there a solution to this without having to get another head. Can you somehow make that one stay or can you buy a replacement seat to press in?
![149514]( "149514")
I never tried to make it stay in ?, I just got my hands on another head. these are defective from the factory, I doubt you will get the seat to stay in the head ?, its not worth the time to try in my book.
on a personal note: I was in the same boat as you years ago, replaced cam chain, cam chain slack adjuster, all of it, just to get it fired up ( and it was a '04 trx350 rancher as well ! ), all was fine, until motor got warmed up, I could bip the throttle, and hear a ticking/clacking ?, I had to make a trip to my local honda dealership, speak to my bud who was lead mech back then, he told me what the problem was, defective valve seats on these years/makes !, sure enough, I got another rancher head from a diff year ( they all are the same for the trx350 ranchers ), problem solved !.
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