cylinder honing

[chiro972]

I'm buying a 2000 220 that the current owner says had the cylinder honed and the piston re-ringed. I asked him about plating and he said the shop didn't say anything about the cylinder being plated. Question is: Does just honing require replating or only if the cylinder is bored?

Don't want to buy a ticking time bomb. Looks like a pretty good deal, but if it is going to blow, I'd better steer clear.

Thanks for your help

 

[fatty_k]

Ask him if he already went to a Weisco piston. You don't want your stock piston blowing up like mine did and causing big $$ in repairs.

 

[Zerotact]

Ask him if he's familiar with the fact that the cylinder has an " electrofusion " coating, and honing the cylinder could damage the coating, I'd stay away, unless you like working on lemons, or save a whole heck of a lot of money

 

[chiro972]

Yeah, I'm getting a good deal, even if I have to have the cylinder replated or resleeved. Does anyone know how to tell if the plating is intact? It looks like I will do a top end tear down before I ever ride this. He also says he doesn't have a shop manual, so I wonder if any of the bolts are torqued to proper specs? What is cheaper and/or better, replating or resleeving? The Wiseco pistons are only listed in one size for the 220, so I assume the cylinder must be within a certain spec. Again, can anyone shed light on how to check?

What is the consensus on what the best repair manual to get, Kawasaki or Clymer? (if one exists)

Thanks for the replies. I would really appreciate it if someone who has done some top end work and knows definitive answers to post a reply. I went to a kawasaki dealership and the techs didn't even know the answers.

 

[fatty_k]

I would send it away and get it re plated. It's probaby cheaper than getting it re sleeved.

 

[chiro972]

My first hope is to inspect it to see if anything needs to be done, but I don't know what to look for, I don't know where to find the info on checking it and most important, I don't trust the local Kaw shop to be able to tell me anything accurate.

 

[chiro972]

There must be someone out there who can tell me what to look for in this cylinder.......If I say please will that help?

 

[acutemp]

chiro,
I would bet that the "honing" that was done to your bike was the use of a ball hone to remove small scratches and prepare the surface for the new rings. I really doubt that any boring or replating should be needed. If it were mine I would tear the top end down and replace the stock piston with a weisco just to be safe. Good luck.--Dan

 

[23jayhawk]

Your first post indicated that the owner had another shop do the work. Call them, and ask if they simply roughed up the cylinder to add some cross-hatch, or if they actually honed it.

If its the former, I'm with acutemp, probably okay so long as compression is strong.

I can't comment on the Clymers manual, but I've not found anything lacking in the factory manual. Seems to have anything I need (so far).

 

[Jim Crenca]

Dan,

What's your current thinking on a re-ring and/or piston replacement in regards to honing? If the bore looks clean do you ball hone in a bit of "tooth" for ring seating or do you leave well enogh alone?

Jim

PS - We miss you technical posts; what's new with your bike?

 

[canyncarvr]

From:

http://ericgorr.com/techarticles/twotopweb.html

Many people have emailed me with questions regarding honing cylinder bores. If you want to buy a hone to deglaze bores or polish off small scratches, then a ball-hone is the best choice.

re: what to look for

You can easily see damage to the plating. When it peels or is 'removed' for whatever reason (like a piston seizure), it's very obviously GONE!

If it's NOT 'gone', then it's probably still ok, wear-wise. The plating isn't usually very thick, so you're not likely to have much of an 'out of round' cylinder with the plate still intact. Certainly if the bike is apart this would be a checking point, though.

EG offers USChrome replates for $175. Langcourt has been reported to be a decent outfit for replating. Note langcourt expressly says they don't want no KIPS stuff...JUST the cylinder.

Let's actually call it like it is here. The guy you bought the bike from is pretty much a maroon if he didn't know the kawi is a plated (or electrofused) bike. While honing can be done to a plated cylinder, what you DON"T want to do is take a stone-fit hone to it. You'll ruin it in the process. (EG notes that in his article, too. Read it!)

Take it apart to check it yourself. It's crucial to have the oem piston OUT of that bike. NOT doing that at rebuild time is asking for disaster. (read fatty's post about his cracked cases and the 220 oem piston).

If YOU put in a wiseco, make sure the piston to cylinder clearance is correct for a forged (wiseco) piston.

LONG before a bike is sleeved, it could be bored and replated to spec.

Keep in mind that boring of a 2-smoke may well change a bunch or port timing issues....and in the case of the kawi, KIPS exhaust port flapper interference issues.

So, honing does NOT require replating. If it was bored, it would be REplated after the bore process.

Don't have anyone replate your cylinder without them having access to the piston you're going to use. Any machinist worth his salt will REFUSE to bore/replate/sleeve or do any other work to a cylinder without having the piston to MATCH it to. Guess that's an imo. I wouldn't deal with a machine shop that was willing to work without the piston(s).

 

[Jim Crenca]

CC,

Been years since I rebuilt a 2-stroke but will be doing a freshen up soon.
Will rings seat properly on a smooth (i.e. used but ok) cylinder?
I'm assuming that if piston condition as well as piston to bore clearance is good, then no need to replace piston.

Jim

 

[acutemp]

Jim,
I usually use a scotch brite pad and work it in a figure eight motion and clean it good with some brake cleaner. This gives the new rings a little something to set into. I recently installed my 4th piston (ProX) and although my cylinder has been ported it is still in pretty good shape with no chipping but some wear. I will probably have have EG do a big bore kit on it when this piston gets tired. I have only replaced just the rings once on the original but since then I do the piston too. Not that it always needs it but it does gets worked pretty hard.
I have been working on getting the jetting right on my 38mm, It sure pulls hard on top :confused: but I still have many more setups to try.
I am mostly working on the motor as I am seriously contemplating doing a KX chassis swap. I spent way to much time at the kart track this summer and having the KX motor would be a good excuse to build a shifter.
I am also looking hard into setting my bike up with an auto clutch which will probably happen after I get some more carb testing in. I've been in touch with Garry from EFM about a product that sounds really promising. They have been testing an auto clutch for the KDX and it should be on the market in a couple of weeks. It will be based on the same design that they are using on their cr450f's which are getting good reveiws from what I've seen so far. The price is still spendy but it's much less than the revloc setup. I will post more info as I get it as there is still research to be done.
I have a ton of photos that I need to get around to putting words to that would make good tech articles. Might make a good new years resolution. :eek:
Happy Holiday's :) --Dan

 

[Jim Crenca]

Fellow KDX'ers,
As always, when Dan gets a minute to post, it is filled with great KDX info.
If I'm not mistaken, much of the R&D on the R&B carb mod is based on Dan's testing; clearly a great source of info that is based on engineering & testing and not personal opinion BS.

An auto clutch at a lower price than Revloc would be great if reliable.
Can you get it to lock up for deceleration by snapping the throttle?
I keep picturing myself crashing on scary downhills without engine breaking.
I also picture myself balsting through the woods without powershifting but also without having to use a clutch.
Please post when you can.

So what's it like to drive a modern shifter kart? I raced competitive B&S 4 strokes 5 years ago (i.e. for non-kart guys, the motors are built by pros and dyno tuned before they get mounted in chaissis, even if it is only a 5 horsepower lawn mower engine with limited porting, stock piston, mostly stock cam, etc. on alcohol).
Back then, the Yamaha 100 cc karts were a bit faster than I wanted to go, and when the first shifter karts showed up, they couldn't hook up.

 

[acutemp]

Jim,
Thank's for the nice words, I do like to throw things at the wall and once and awhile something sticks. I get alot of enjoyment out of testing new ideas but it really takes the collective testing and sharing the feedback by good people like yourself and many others to really get the most out of any modifcation. And don't worry I have plenty of personal BS :confused:

The autclutch is something that has interested me since I heard about the revloc. The area's that I ride are tight and nasty and I tend to brake stall more than I'd like. For some reason my foot alway hits the brake before my hand gets to the clutch, must be old age. :ugg: I have a flywheel weight that really helps with this but I prefer to run without it if I can. The autoclutch should work great in these conditions.
Engine breaking should be no problem as the clutch engages just above idle so you won't be freewheeling down the hills. It works like a torque converter in a car. If you roll the throttle on easy it takes off nice and easy but if you twist it hard it will just rev to a certain rpm and pull untill the bike catches up.
They should be doing the testing now on the first units and will then tear them down to see how they are holding up. I will update when I find out more details.

Jim, if you get the chance to beg borrow or steal a ride in one of the new kart's by all means DO IT! The 125 shifters are 45+HP, 125mph,3g's, and 0 to 60 in under 4 seconds! Their lap times are about even with the indy cars at PIR. I havent driven one of these yet but I've had several of them blow by me on the straight's! I've been driving a 125 Rotax max 125 that is a sealed motor kart with 28 HP, auto clutch single speed, and best of all an electric start. They handle like they are on rails and although I have spun out several times they are a very safe way to get the heart rate up! Way to much fun and a great summer sport for when the woods are closed for riding.

--Dan