r.2 stroke

~SPONSOR~
Dec 29, 2001
73
0
hey there guys,merry christmas!sorry to go over old ground again for most of you,but,i've got a 1999 220r(bought new in nov'99)and i put in a new piston kit(o.e.m) at the beginning of this year and done about 40hrs riding on it so far,with no problems that i'm aware of.My question is ,am i on borrowed time as far as the piston is concerned?I've been reading the archives(a great resource!)and it seems like the stock(o.e.m) piston sounds like a horror story and get the wiseco,is this true?

1999kdx220r
fmf 909 bars
fmf kg-30 pipe,t-c 2 silencer
air box mod
#40 pilot,#145-148 main,needle 2nd clip from top
12t front sprocket
meztler mc5 tyres
 

penguin

~SPONSOR~
N. Texas SP
Feb 19, 2000
390
0
I have not heard of this as a widespread problem. I sent Canadian Dave an email to get his input on this supposed problem. Since I just got an 02 220 I would like to know myself..
 

Fred T

Mi. Trail Riders
LIFETIME SPONSOR
Mar 23, 2001
5,272
2
I rode in fear all year...

and after 19 rides and 1200 trail miles it never exploded. IMy friend talked to Jeff Fredette and he said that the piston can crack in the 220. The dealer never heard of such a thing so my take is that on a 200 they never have a problem and on the 220 it happens more that on a 200. So you decide. I'm putting a weisco in mine this off season especially because I've modded my carb and will rev it a little harder next season so I don't want it to explode and take out more expensive parts. Tough call, I know.
 

BRush

LIFETIME SPONSOR
Jun 5, 2000
1,100
0
The 220s have had some problems with pistons cracking (the 200 piston is fine). Not every piston is defective (probably the majority are fine), but insofar as I know there's no way to tell if yours is one or not. The consensus seems to be that if your bike is basically stock, you don't have as much to worry about as someone who's done mods to increase the engine output. You may never have a problem in either case. It's not like there have been exploding 220's right and left, so if it was me I'd chance it until winter maintenance/top end time came around then replace the piston - but that's my own personal tolerance for risk. If you are someone who switched over to Goodyear tires on your Ford Explorer the day after the first news reports about the Firestone Wilderness A/T, you may want to take action sooner. ;)
 

Canadian Dave

Super Power AssClown
Apr 28, 1999
1,202
0
BRush has hit the nail right on the head. Yes there have been occasions where the stock 220 pistons have cracked. Is it going to be a concern for every 220 owner, certainly not. There are some common denominators however than can help you decide if exchanging your stock 220 piston for a Wiseco is warranted or not. 220s that have been modified to deliver more power, bikes that are ridden hard and pistons that have seen a more than average amount of service will all be more prone cracking. I don't think every 220 owner is sitting on a time bomb by any stretch of the imagination but if you've installed a pipe and are an aggressive rider than you might consider replacing your stock 220 piston a little sooner than you might normally and when you do I'd suggest installing a Wiseco. Even if your 220 is stock I think its worth the extra piece of mind to go with a Wiseco when you service your top end. Whether you rebuild your top end sooner than you might normally is totally depended on your comfort level. I like Brush's Firestone analogy. There's no sense going with a potentially weaker stock piston when the Wiseco piston is readily available, cheaper and has a reputation for good service in 220s.

When switching to a Wiseco you might consider ordering a second set of rings as the same time. The stock rings and Wiseco rings aren't interchangeable. If you are a person who normally measures and rerings a piston rather than simply replacing the piston when servicing your top end you'll need to order the rings, your dealer, unless you normally deal with someone like Fredette or Sage, wont have them in stock.

The stock 200 piston hasn’t displayed any tendency to crack and there is no reason not to continue using stock pistons in the 200.

David
 

XR400RMan

Member
Dec 11, 2000
213
0
I don't mean to sound like a nut here but what excatly happens or can happen to the KDX220 top-End if the piston explodes. I know on a 4-Stroke engine it might destroy the Head and the Valves and leaving your wallet empty after its fixed. So what could happen to the 220 engine? Thanks Matt

P.S I am probably asking a dump question.
 

Canadian Dave

Super Power AssClown
Apr 28, 1999
1,202
0
Really anything from mild to wild damage can occure. Something as simple as a damaged piston to a distroyed cylinder, head, con. rod etc.

Sage you've had it happen on your own bike and likely repaired others who have as well, what's the typical scynario?

David
 

Sage

dirtbike riding roadracer
Mar 28, 2001
621
0
It usually starts with the left or right lower corner cracking from the intake window down, if you don't catch it in time the piece will break off and follow the path of the air flow, sometimes it will lock the crank to the cases, sometimes it will trash the cylinder ports on the way out and sometimes it just leaves with little to no trace that it was there - it really depends on how lucky you are and the rpm the engine is at when it lets loose. I've cracked the stock & wiseco pistons in my engine (220), so every 3 months or when the engine starts getting loud I'll pull the reed cage and have a look, usually you can tell when it needs a piston by the way the engine sounds with a new piston compared to a used piston.

The 220 uses some plywood looking piston with a small leaf stamped into it and the 200 uses a ART piston, the Pro-x pistons are also a ART piston as many other stock 125 & 250 pistons, no Pro-x piston for the 220 without going over size. :mad:
 

r.2 stroke

~SPONSOR~
Dec 29, 2001
73
0
Thanks for all your help guys,
maybe this cracking was a problem with a particular production run and it's sorted out now,i don't know,i checked the original piston out and it looked o.k(i guess hard to be really sure without crack testing),did about 80-90hrs on it before slipping in another o.e.m one,interesting to hear Sage,that you have cracked a wiseco at one time
 
Top Bottom