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View Full Version : What causes ring ridge?


Honda_Matt
08-25-2008, 04:36 PM
I dont know, never had alot of experience with ridging.

My buddy races his YFZ and lost compression, went to do a top end rebuild and he has ring ridge on top and bottom of his cylinder.

Since it's a coated cylinder they'd have to send it out, so he's just buying a new cylinder.

What causes it? It is just normal wear, high or abusive RPM?

Lack of oil, too lean, too rich?


Thanks
Ride1Rob
08-26-2008, 10:02 AM
What's ring ridge?
ohsobad_chevy
08-26-2008, 03:06 PM
Originally posted by Ride1Rob
What's ring ridge?
Honda_Matt
08-28-2008, 09:52 AM
A ridge in the cylinder where it comes in contact with the rings, like it's digging in.

If you take your finger nail and drag it across the cylidner wall from top to bottom, you will feel a change in the bore and that is ring ridge.
Ride1Rob
08-28-2008, 11:42 AM
Normally this happens in 04-05 bikes bc of the stroke angle at TDC & BDC. The shorter stroke has tendency to cause more wear on the cylinder walls in those areas.
Honda_Matt
08-29-2008, 05:10 AM
The bike it happened on is a 07.
Ride1Rob
08-29-2008, 07:44 AM
How much time on the topend and what kind of oil is used in the bike? I put the 06 crank in my 04 and have almost 2 yrs. on my cylinder. When I checked the top end a couple of months ago the cylinder was still in very good condition with no scarring.
Honda_Matt
09-02-2008, 06:38 AM
I think the bike had 22hrs total time.

Got it brand new and had MXP do a ton of work to it.

Uses YamaLube 4R... I cant remember the weight.

20/15 I think but im not positive
rt20ps
09-04-2008, 06:51 AM
I would guess he isn't maintaining his air filter properly. I just tore down an 07 Raptor and the plating is worn through at the top of the stroke. It was full of dirt.

The Yamaha cylinders are pretty durable but he may have gotten a bad one. Have you seen it yourself?? It is normal to see a ridge at the top of the cylinder above the rings caused by carbon. A good brush hone and some carb cleaner will take care of it. Can any cross hatching still be seen?

When you say it lost compression, was a leak down test done?? I would check the head and valves also. You may be overlooking the real problem. Can you take a picture of the cylinder??
Honda_Matt
09-04-2008, 08:48 AM
It wasnt a carbon build up, it was into the cylinder itself.

Yes a leakdown test was done.

Replaced the cylinder and a new piston and rings and it's all good now.

Only reason he replaced the cylinder was he didnt have time to send it out for a re-bore and plating job.

Now he's going to have that done for a backup cylinder.