R6 Message Net banner
1 - 8 of 8 Posts

·
Registered
Joined
·
18 Posts
Discussion Starter · #1 ·
I have had a look into the Cylinder of my dead R6 engine and about 2cm down from the top there is a 1cm square chunk (about 1mm deep) that is missing, the hole is clean and smooth and would indicate there may have been a manufacturing defect i.e. air gap when the engine was cast.

I've looked at a number of business that offer a welding/re-plating service, does anyone have any knowledge of doing this on a r6/R1 engine (or a similar engine where the aluminum bore is plated), and is repairing a bore this way reliable?

I'm keen to avoid repair, rebuild and a further issue with the engine failing.

Thanks
 

·
^s Own The Messagenet
Joined
·
1,123 Posts
pictures would help.
 

·
Registered
Joined
·
1,291 Posts
yes, replating of the cyliner makes for a reliable block. No issues if done by a reputable shop. has the motor been rebuilt before or bone stock from factory? i had this happen when a dealer decided they knew what they were doing and folded the ring over along the piston when trying to put a motor together. They then hammered the thing in and it took a chunk outa the cylinder. .. i never run motors without having MY guys look em over and we discovered the issue prior to running. they replaced the block free of charge.. Yamaha motors are VERY tricky to put together due to the irregular cylinder shape at the bottom, makes putting the piston/ring into the sleeve tricky.
 

·
Registered
Joined
·
18 Posts
Discussion Starter · #4 ·
Motor is standard, I was more concerned about the bore coating and had been told some R6 engines (I think 2003 on) have the outer layer of the bore made from a slightly different aluminum, this can cause rippling when welding??

I've got a couple of companies who I've now asked on prices for rewelding, honing and coating.

I'll try to get some pictures as it would interest many to see the damage.
 

·
Registered
Joined
·
61 Posts
This exact thing happened to my engine. Ive been looking for new cases to no avail.

Is this repairable? I have a 1cm wide by 1mm deep chuck missing from the top of cyl #1 accompanied by a nice crack down most of the cylinder..

Any input would be greatly appreciated..
 

·
Registered
Joined
·
125 Posts
I found a 1" square section of cylinder wall that had worn thru on my 99 motor (#1 cylinder). My wife is the service manager at a Yamaha dealer so I get a good price on parts but it was still gonna cost more to repair the motor than buy a used motor on on E BAY. Believe it or not....I found an 02 motor with 400 miless on it for $250.! It was a back up motor for a guy that raced back in 2002 and he never used it. (been sitting in a box for the last 6 years.)
 

·
Registered
Joined
·
125 Posts
I think this problem is only apparent on high mileage motors. If you can find a low milage motor...I don't think it'll be a problem. But you're right, ya don't really know what you're getting. I just got lucky cause I actually know the guy I got mine from.
 
1 - 8 of 8 Posts
Top