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when to get a new top end?

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i prolly have like 50 hours on my bike. my dad says i need to get a new top end. i dont race i mostly ride trails.never revs to high.

so do i have to get a new top end?

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I think you should. New valves, springs, cam chain, piston, rings, gaskets, ect....

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I don't know if you do need it. Maybe you should check your valves, check your compression too. If you still have good compression and your valves are in spec, then there is there really a reason to change your top end? Do you really want to get in there and diddle with your engine that Honda put together?

I redid my top end and I'm not sure I'm getting the compression I'm supposed to. Anyway, there are other experts out there that will tell you what to do.

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Well i would check your valves and see if there in good clearence. And if they are then maybe just a piston only wouldnt be to bad of an investment.

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I dont think you can check the compression on these motors because of the automatic decompression. I would check the valves and go from there. I would put an hourmeter on the bike because you hit around the 75-100 hour mark, I would do a top end on the bike, but at 50 hours of trail riding your fine.

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they manual recomends to do it at 50 hours, but i think it refers to mx ie: High Revs, but you said you dont rev it much, id say puy it apart check valve clearances, shims etc, and if they seem alright leave it for like 15-20 hours :thumbsup:

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If you havn't had to shim your valves but once after break in I would say just throw a new set of pistion rings in there and let it be. If your only trail riding your top end will probably last you a good 80-100hrs. If you get a valve that zeros out soon then do your top end.

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This is a good question, Im in a similar boat: about 50 hrs. MX riding but at an older mans speed and level :thumbsup:

Other than the valve specs, isnt there some other symptom that would occur indicating its time to overhaul? My bike is running fine. I really dont want to spend the money or time if its not symptomatic in anyway. What should you look for as a sign of impending top end work needed?

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Well maybe if you know someone who has a new CRF. Ask if you can ride there bike, and if yours just doesnt feel any where near as crisp in the motor(which a used bike always will compaired to new) then you might be indeed of a little freshening up. Oh and dont forget that if you put a new piston in remember to throw a new timing chain in(save you a lot of headache).

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i would put new rings in it, and check you valves, maybe replace you valves or piston depending on how they look. more than likely you should put some rings in it and shim those valves. think about a new clutch too.

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Dont Fix It If It Isnt Broken.

Thats what I was thinking. So whats the first sign (valve clearance?).

I also suspect its true that the gradual degradation could leave you missing power and crispness but not really realizing it until you got on a fresh rebuild bike or a new bike.

Regardless, no time or cash to repair unless broken here :thumbsup:

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It says in the Helm Service manual how to do a compression check on it. I wouldnt worry about it until it becomes a problem. Check your valves and change oil.

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