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yamiguy51

07 450 reliability???

12 posts in this topic

Ive got 140 hours on my 07 yami 450 havent touched the motor yet. Should i replace the top end soon?piston, rings, gaskets and valve springs????????. Still starts easy and still gots plenty of power. What too doo!!??

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Not sure about all those but id DEFINATELY change my cam chain if your not going to do anything else or havent already done so

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Ive got 140 hours on my 07 yami 450 havent touched the motor yet. Should i replace the top end soon?piston, rings, gaskets and valve springs????????. Still starts easy and still gots plenty of power. What too doo!!??

I have 40 hours on mine. At 100 hours, I plan to replace the piston, rings, and cam chain. If the valves look good I will run with it for another 100.

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Yeah, replace the cam chain and the piston. Bike will rip like new or maybe beter. Its also a good Idea to check the valves before you remove the cams, so you know where your at.

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I believe a lot depends upon what you use the bike for. If you race then most certainly you need to stick closely to the recommended maintenance schedule. If you are a weekend warrior like myself, and do not ride the bike like a racer, then the service periods can be extended.

I am a fan of regular routine maintenance (oil changes etc), these are essential for reliability however if the bike is running OK with no noticeable performance drop, leave it alone.

I do agree however that some items need changing routinely such as cam chains.

You will notice there are many posts from people who are running YZ400's, 426's, and early 450's who have run them for years without any problems.

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looks like ill be spending around 240bucks for everything from motosport oem products piston, piston clips, rings, gaskets, cam chain, and valve springs :0

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im looking for the same answer.

what about a leak down test? if all still in the good range, it will determinant that the rings and valves are still in good shape and in spec for 100 more?, or does it just show that they still seal correctly when off?

then should i still open her up for a new piston just for the fun of it ?

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A leak down tells the current condition. The question of how much farther one can go from any point is really pretty impossible to answer.

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i have a compression tester but when i start my bike it has the auto decompression so its not putting all the presuure its suppose to be? or does it not matter? if not what is good compression?

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You cannot do a meaningful compression test with any motorcycle with auto decompression, and without it, the compression is so high in a healthy engine that you can't turn it over to do one anyway.

A leak down test is the only acceptable approach, and will tell you a lot more in any case.

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A leak down tells the current condition. The question of how much farther one can go from any point is really pretty impossible to answer.

then leak down test every few hours will only give a little extra insurace. :ride:

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