atc 185/200 head work

[adam38654]

When installing a new clyinder and cam should I replace the timing chain if I don't have to? Also would it be beneficial to re-lap the valves?

If the valves look too worn could new ones be lapped of do the seats have to be re-cut?

[350for350]

I suppose whether or not you "should" replace your cam chain depends on several things. How old is it? Does it have a lot of wear? How much peace-of-mind do you want to have? It seems to me that now would be the time to do it since the engine's already apart and it will be a lot simpler than tearing it all back apart. I'd think that it would be beneficial to lap your valves since you have the head apart. I think that if the valves have enough wear to need replacement, then the seats should be ground or replaced since they wear together. Granted, I believe the seats are made out of a harder material and may not need to be replaced. Hope this helps. It's just my advice.

[Scootertrash]

For 20 bucks replacing the cam chain is cheap insurance. A broken cam chain can reek havoc on your lower end if it breaks.

http://www.ebay.com/itm/DID-Cam-Chain-25H-X-100-Honda-TRX200-1984-25H100-/371886081510?hash=item56962345e6:g:v0EAAOSw4A5Yvy3 n&vxp=mtr

My machinist charges 60 bucks for a valve job. I just have him do it. The majority of the Honda 185/200's I have taken to him have a burned exhaust valve.

[motor1066]

i ussualy hand lap the valves in if they look good. i have re used timing chains. i always take a close look at them and the adjusters. if u got the motor on the bench it is a little more work but if you have the extra hour and 20 bucks it might be worth it to just do it if trailprotrailpro not in a time pinch. but i dont think its the end of the world to reuse one. a flywheel puller is about 10 dollars also. and makes easy work of removing the flywheel. def worth it

[adam38654]

I feel confident I can inspect the chain and cam gear for unusual wear and tear for I was just afraid an overly stretched chain may be undetected and throw the timing off.

I have some Junky $200 atc's I may just re-lap the old valves or try to lap in a set of $20 shindy valves, but on my 200s with 12:1 piston and stage-2 cam I will spend the extra on a new cam chain and kibble white stainless valves. I don't have the tools to cut the Valve seats so I was considering G&H discount atv head service for $140 that includes shindy valves or is $20 less if you supply your own. But I found a local cycle shop that will work the head for $100 with my supplied valves.

[motor1066]

what stage 2 cam are u using. i tried to find one for my 185s. all i found that would work is the xr200 cam.

[adam38654]

Web cams offers several grinds for the atc/xr 185/200 engine. They are kind of high at $166 plus core but it is a much more radical lift than the xr200 cam.

[yaegerb]

When installing a new clyinder and cam should I replace the timing chain if I don't have to? Also would it be beneficial to re-lap the valves?

If the valves look too worn could new ones be lapped of do the seats have to be re-cut?

Yes on cam chain, cheap insurance. You can test the valve seat by placing the valve in the guide leaving a 1 inch or so gap. Then pour marvel mystery oil in the valve pocket and shut the valve. Turn the head right side up while holding moderate pressure on the valve face. If you see oil weeping around the seat then you need to lap them or potentially have them re cut if there's to much damage.

[barnett468]

.
If the valve springs are on you can check the valves for leaks by cleaning the combustion chamber around the valves with a wire brush and carb cleaner if it is dirty, then spray carb cleaner or brake cleaner in one port or pour some lacquer thinner in it etc then hold the head up so you can see the valve and see if it leaks . Do the same thing to the next port, however, even if they do not leak, it is still possible that they are worn and may leak soon or the valve stems and/or guides are excessively worn so those should also be checked.



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