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View Full Version : Replating vs. sleeving cylinders



crazyxr250rider
5th May 2008, 20:02
I will be rebuilding a RM250K5 some time in the next month or so and wondering what others opinions are on this.
Calling people with reasonable mechanical knowledge....(Eg, Reckless, Danger)
Thanks.

Buddy L
5th May 2008, 20:51
i wouldn't think you would need to replate or sleeve a bike of this age, but i supose it depends on use and abuse.
check condition of power vavles
replace all bearings sence the motor will be apart anyway. (peace of mind)

Quicker_with_age
5th May 2008, 20:56
wouldn't think you would need to replate or sleeve a bike of this age, but i supose it depends on use and abuse.

Only if the bike has been seized etc he will.

I recently rebuilt my mates bike which had seized and made a hell of a mess of the bore, We decided to go with a cast iron sleeve which gives the option or a rebore or hone should it be damaged again in the future, I also think it was the cheaper faster option, He did comment that it was down a little on power than before so whether or not this was due to extra friction from the cast bore or not im not sure.

sugilite
5th May 2008, 20:58
I tried both methods on my KX500. I noticed a definite loss in power when I re sleeved it, and wish I hadn't done that. I recomend a replate. :yes:

Robert Taylor
5th May 2008, 21:25
I tried both methods on my KX500. I noticed a definite loss in power when I re sleeved it, and wish I hadn't done that. I recomend a replate. :yes:

I concur, when you purchase a sleeve and have it pressed in there is in fact a lot of port finishing to do. That requires a small precision right angle die grinder, port roof angle templates, an alloy slug machined up to gauge port heights and matching of AND lots of very fastidious hours. To do this properly would in fact make the job more expensive than replating. ( And you also have to very carefully pick your replating agents! )
As so often happens people see resleeving of a 2 stroke cylinder as a cheap way out, they invariably always get a cheap job and a horsepower deficit. If you are buying a bike that is resleeved it effectively has a lesser value.

Katman
5th May 2008, 21:53
And there is now an outfit doing the replating here in NZ. No need to send them to Aussie anymore.

(Will look up their business name when I get into work tomorrow).

Kickaha
6th May 2008, 06:30
And there is now an outfit doing the replating here in NZ.

http://www.engineservices.co.nz/cylinder%20plating.htm

crazyxr250rider
6th May 2008, 07:11
I know it needs it engine is apart. Nice big gouge below intake port (Air Filter caked in dust)And im replacing all shell bearings and the mains but no others as the bike has very low hours. (obviously small end bearing with the piston..)

crazyxr250rider
6th May 2008, 07:25
Good Info guys. Heard of some plating flakeing after less than 10-15hrs running around ports is there any outfits to stay away from????

Danger
6th May 2008, 08:20
I'm sorry, I can't help you with this. I'm trying to think of the guy in Barrys point road that has been rebuilding engines for years who could advise you but the name of his business escapes me. Something like Presicion Engine Rebuilders or something? Someone might chime in. I have not used him since the 80's when cylinders needed boring but he is still around from what I hear.
Pulled mine apart last night and almost got it back togeather with a Wiseco Prolite piston. The RM is very easy to work on.

crazyxr250rider
6th May 2008, 09:09
Yea im putting a wiseco in there (like every other bike I own....)

sugilite
6th May 2008, 12:02
I see your sold on wiseco, but just a blurb from what happened to me. This maybe just a big bore issue, but I went to the expense of getting my cylinder replated, then put a wiseco piston in as I did not like kawasaki nz extortion on a oem one. I had the piston skirts drilled for extra lubrication. Unfortunately the expansion rate was different on a wiseco to standard and it seized cracking one of the port bridges. And yes, I was really careful to warm it up 1st. Like I say, may just effect 500's. suddenly the oem piston did not look so expensive :cry:

crazyxr250rider
6th May 2008, 17:22
Are you shure it was the Piston??? Not just bad plating ive heard lots of stories about the plating coming unstuck on the port bridges. Where did you get it done? ive never had any trouble and had increased performance over standard.

F5 Dave
6th May 2008, 17:33
I'll only ever use US chrome http://www.usnicom.com/, their work has been great & they aren't that expensive. Better to get it done once than pay for 2 cheaper jobs, played that game before, gets boring. They will match it to piston &/or sell you a wiseco.

Actually price is pretty good. Have to mark as 2nd hand for repair & post it, if courier will get screwed up in customs.

crazyxr250rider
6th May 2008, 20:48
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Katman
6th May 2008, 21:31
Unfortunately the expansion rate was different on a wiseco to standard and it seized cracking one of the port bridges.

On the 500s the exhaust port bridge must be given additional clearance. Obviously this has to be done before the replating. Maybe whoever did the replating wasn't aware of this requirement or just plain forgot.

Robert Taylor
6th May 2008, 21:55
Yea im putting a wiseco in there (like every other bike I own....)

I hope the NZ agent starts off doing a better job than the ockers. I used to send a lot away and sent them to Langcourt in the UK, never a problem. Wisecos are forged pistons ( and are very strong ) BUT they do expand / grow more when hot. They require bigger clearance than cast high silicon low expansion oem. Do yourself a favour on this one and stick to oem.

sugilite
6th May 2008, 22:41
On the 500s the exhaust port bridge must be given additional clearance. Obviously this has to be done before the replating. Maybe whoever did the replating wasn't aware of this requirement or just plain forgot.

I Did not realize I was going wiseco when I sent it away, so it was not their fault.Thanks for the info though! :yes:


I hope the NZ agent starts off doing a better job than the ockers. I used to send a lot away and sent them to Langcourt in the UK, never a problem. Wisecos are forged pistons ( and are very strong ) BUT they do expand / grow more when hot. They require bigger clearance than cast high silicon low expansion oem. Do yourself a favour on this one and stick to oem.

I too have heard bad news about the aussie workmanship. That UK outfit that you are the agent for have always done good work on my barrels and the others I know of that used their/your service. For the record I rang the NZ outfit today and they quoted more for the job than your UK based outfit!


Are you shure it was the Piston??? Not just bad plating ive heard lots of stories about the plating coming unstuck on the port bridges. Where did you get it done? ive never had any trouble and had increased performance over standard.

Absolutely no flaking on the barrel, if it were not for the cracked port bridge, I could of just whacked a oem piston in and gone again. It seized solid on the last lap of the 1st race on manfield's front straight (motard) and I'd just done a 1:18 flat, still the lap record for motard bike as far as I know. It seized BIG time. But the bore was still flawless bar the cracked port bridge, so that speaks volumes for the quality of work. Robert (poster above) warned me about using wiseco, and I paid the price for not listening. Lesson learned.

F5 Dave
7th May 2008, 09:24
Weird, works for me just fine, try typing the address into location bar, should work fine. or just google it, it will come up.