1999 yz400f busted cam bracket

[jj1479]

Does my piston need replaced or can it still use it? I see the wrist pin is worn.

[bakeyz426f]

i would how old is it

[grayracer513]

It doesn't matter what it is now, only which compression ratio you want. The piston is what determines the CR.

As far as whether to replace it, bear in mind, it ran into the valves. I'd advise replacing it.

[jj1479]

i would how old is it

I really don't know as i bought the bike used. The only markings on the piston are on the underside and their is a Y on the left side and a #4 on the right side. So i don't know if its factory or not.

[jj1479]

It doesn't matter what it is now, only which compression ratio you want. The piston is what determines the CR.

As far as whether to replace it, bear in mind, it ran into the valves. I'd advise replacing it.

Is their any way to tell what CR piston i have?

Do i have to re jet my carb if i put a different CR piston in it.

I'm still waiting to hear from Engine Eynamics about my head.

They got it sometime last week and I'm waiting to see if the valves were bent also as one of the intake valves was open about an 1/8" with the cams off.

[grayracer513]

Is their any way to tell what CR piston i have?

Do i have to re jet my carb if i put a different CR piston in it.

Not very easily, and no, in that order. But looking at your piston, I'd guess it was stock, 12.5:1.

[jj1479]

Well Engine Dynamics just called my head is finally done. But it also needed a cam journal repair. So they are shipping it out tomorrow and total price with shipping and insurance it was only $402.77. Now my question is can i hone the cylinder my self or should i take it to a machine shop?

[grayracer513]

Read:

https://www.thumpertalk.com/forum/showthread.php?p=4380759#post4380759

A shop would likely charge no more than $20, tops.

[jj1479]

well got my head back this morning and there was a paper taped to the top saying to torq the cam cap bolts to 5ftlbs only.

[jj1479]

Read:

https://www.thumpertalk.com/forum/showthread.php?p=4380759#post4380759

A shop would likely charge no more than $20, tops.

I took it to Rhoads Performance Machine and they wanted $55 to hone it out. Thats the only place with in about 20 miles from me.

I stooped at NAPA and for a the (bottle brush hone) fine grit it was $156.00 for the 3.50"to 4" hone.

Auto Zone and Advanced Auto only carry the one's with the stones. So i just bought the one with the three stones and bought the fine 400 grit stones for it that was only $34 total.

I soaked it down with oil and it only took about 15-20 times up and down with my drill at half speed to get it even.

[jj1479]

Couple of pics of the fixed cam bracket and the new wiseco piston installed.

http://i636.photobucket.com/albums/uu88/jj1479/fixedcambracket.jpg[/img]"]

http://i636.photobucket.com/albums/uu88/jj1479/fixedcambracket2.jpg[/img]"]

http://i636.photobucket.com/albums/uu88/jj1479/piston.jpg[/img]"]

[grayracer513]

... So i just bought the one with the three stones and bought the fine 400 grit stones for it that was only $34 total.

I soaked it down with oil and it only took about 15-20 times up and down with my drill at half speed to get it even.

I said to use a bottle brush hone specifically because you should NOT use a fixed stone hone.

[jj1479]

I said to use a bottle brush hone specifically because you should NOT use a fixed stone hone.

I know but Rhoads said it wouldn't be done till around tuesday if i wanted them to do it cause their backed up.

I couldn't see spending $156 for something that will get used for about 2-3minutes. Plus i'll never use it again. Also i was in kind of a hurry to get it done to go rideing and really didn't think about it..

Why can't you use a fixed stone?

[grayracer513]

Your goal is to refinish the surface of the used cylinder bore without removing any more than the minimum amount of material necessary, or changing the shape of the bore in the process. Ball hones comply with the shape of the bore, and accomplish a near perfect resurfacing for ring seating while removing very little material. Fixed stone hones tend not to touch any low spots until the high spots are knocked down enough to let the stones contact them. Nikasil plating is very thin, and it's not good to remove any of it if it can be avoided.

Fortunately, it's also very hard, harder than some abrasives are, and with the price you paid for the hone, it may well be that the hone was reshaped by the cylinder more than the cylinder was reshaped by the hone.