Top end, or not top end...

[BraveG]

Hullo chaps,

As I mentioned in my intro, I have just picked up a 93 KDX200 in fairly good nick and am planning to use it for weekend bush-bashing.

The previous owner claims to have done roughly 150 hours on it (no idea how many hours the owner before him did) and regularly serviced it about once a year for 10 years or so. As far as he recalls, the top end was never redone, but it still sounds great and runs well as far as I can tell.

So the question is, even though it's running well, should I pull the top end and redo with new piston and rings? I am concerned that riding it now will increase the danger of the top end blowing up and then having to fork out more money than I have to do a rebore and am thinking it might be best to just redo the top end and save potentially spending a lot more in the short run.

On top of this, are there any extra engine related elements that I need to factor in with a 20 year old engine ie cleaning out KIpS, replacing seals etc?
I will be doing all the standard maintenance to get the bike back in shape, and have the mechanical chops to do most engine work, but all my experience is with 4T bikes, so I'm eager to hear your thoughts.

Tx G

[scheckaet]

do it, cheap piece of mind, clean it all while you are there and inspect plating.

[Gotanubike]

I had a lot of fun doing the top end on my E series when I got it last year. Really simple 20 minute procedure to take the whole top end off. Gaskets are fairly cheap...Make sure you have a manual for tackling the KIPS. They are easiest to work on with the whole cylinder on your work bench. And for the love of all that is holy, watch out for reverse threaded nuts.

[scheckaet]

check my sig for newb thread

[BraveG]

check my sig for newb thread

:) thanks man, was the first post I read here :) tx for advice guys, will order a piston kit tomorrow and get that underway. One more question, when redoing the top end, will I need a gasket or seal kit as well or can I reuse what is already on the bike?

[Fitterman24]

check my sig for newb thread

:) thanks man, was the first post I read here :) tx for advice guys, will order a piston kit tomorrow and get that underway. One more question, when redoing the top end, will I need a gasket or seal kit as well or can I reuse what is already on the bike?

Always use new gaskets, period! Once it's torqued down, that's it for that gasket. If you forget something and have to pull it apart 5 min later you should still get a new gasket. Just my 2 cents

[Gotanubike]

The base gasket is just paper and only about $5 from the dealer, you'll definitely need to replace that...the head gaskets are around $20. They are non composite steel with a raised outer seal that gets squished when you tighten it. if you're going to reuse that, make sure the head surface is perfectly flat.

You can check that with a pane of glass and a sheet of fine grit sand paper. Do figure 8's with the head on the sand paper until you get it perfectly flat contact surface.

No other seals in the top end other than maybe the bushing guide on the right side for the KIPS rod,, but that bushing does not need to be removed, it's easier to remove the rod from the left side.

[BraveG]

check my sig for newb thread

Great thanks chaps, will keep you posted on progress
G

[Keystone]

I just bought a '93 this winter and rebuilt the top-end. It took me about three weeks longer than most people but it was a very satisfying experience, and glad I did it. I spent alot of time ordering parts as I figured out I needed them during the rebuild, my very first. For example (I later figured out), to torque the head back down you will need this motion pro torque wrench extension. A simple torque wrench won't get in there and a short "crows foot" adapter wont get it either. Don't forget to do some math and adjust the torque specs for the extension.

[Gotanubike]

I was able to use a regular 3/8ths torque wrench for the head...I think I had to swap the extension on or off for one or two cause the frame was in the way...Maybe you're referring to the 4 jug bolts? I guesstimated those a bit tighter than 18ft/lbs for the head ones.

[Keystone]

I guesstimated those a bit tighter than 18ft/lbs for the head ones.

I calculated slightly less than 18ft/lbs for the head ones. For example, the manual calls for 18ft/lbs so with my 15" torque wrench + 3" adapter, the new torque setting was 15ft/lbs. On the cylinder I used the adapter on all the bolts. On the head I had to keep switching from 18ft/lbs (when I did not use the 3" extension) to 15ft/lbs (when I did use the extension) to get them all torqued down the same.

So the torque wrench with 3" extension would register 15ft/lbs but nuts would be tightened to 18ft/lbs.

[diymirage]

check my sig for newb thread

:) thanks man, was the first post I read here :) tx for advice guys, will order a piston kit tomorrow and get that underway. One more question, when redoing the top end, will I need a gasket or seal kit as well or can I reuse what is already on the bike?

I wouldn't order a piston kit until I inspected it first
what if the top end has been redone once and you are not longer running the stock bore ?

now your stuck with a piston that wont fit and you will have to sell on here for half price


once you are ready to buy a piston I would just go ahead and buy a top end kit
it is cheaper then piecing it all together and comes with all the gaskets you will need

[BraveG]

Good point! Will crack it open this week and see what's what.

Tx chaps

[SS109]

A lot of great advice in here. Nothing to add to what has already been said except to only use factory Kawasaki head and base gaskets. An aftermarket base gasket of the incorrect thickness and/or material can actually change your port timing and compression ever so slightly but it does make a difference. IMO/IME factory head gaskets always seal better than aftermarket versions and, like with the base gasket, improper thickness can affect your compression.

[Joshmcmillan]

I have also successfully torqued head bolts on multiple KDX200's with a normal 1/2" torque wrench and a long extension (with seat etc.. off of coarse)

[GOT WOODS?]

A lot of great advice in here. Nothing to add to what has already been said except to only use factory Kawasaki head and base gaskets. An aftermarket base gasket of the incorrect thickness and/or material can actually change your port timing and compression ever so slightly but it does make a difference. IMO/IME factory head gaskets always seal better than aftermarket versions and, like with the base gasket, improper thickness can affect your compression.

Hmmmmm, now you have me thinking. How about the Cometic? Do people find these to be a good fit or do they have the potential for the issues described above? I was just about to pull the trigger on the Cometic top end kit for my exploratory surgery to find out if I have the infamous exploding KDX 220 piston. If this is an issue though, then I'll go stock with the head and base gasket.

[SS109]

I know some will say the Cometics are fine. However, are they made from the same material and same thickness? I don't know. You could measure them but then you still wouldn't know the exact material they were made from. There are so many different steel alloys and different paper gasket compositions, with varying compression properties, that you would never know for sure without true scientific analysis!

[diymirage]

I've been told cometic is the same as OEM
however, my only indulgence is that when it comes to top end kits I only buy wiseco

[scheckaet]

i have used cometic and another gasket brand (tusk?) I can't recall and didn't notice any issue...
If you'll sleep better at night knoiwing you used OEM ... then use that price difference ain't that much.

[fuzzy]

Personally I'd run it after a compression check came up good. If not, then refresh. Clean KIPS, if dirty. You'd be surprised how many miles can get piled up on one of these with trail use.