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TheBavarian

New owner 1997 RMX250V: General info, manual and aftermarket protection (WA, USA)

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Took off the rear brake pedal, kickstarter, clutch and carb.

How do I remove the reed valve to check it? I removed the six screws holding intake pipe, but the valve won't come out. Is it pressed into the case opening? Don't want to damage it by trying to force it.

Rest looks good so far. As you mentioned, the kickstarter was stuck on the splines. Had to improvise a small gear puller with a c-clamp to get it off.

I'll also finally open up the top end today.

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Reedcage is just stuck on the gasket. It’s actually a loose fit into the case. Try using a hammer and block of wood to soften the blow and tap on the edge of the cage. If that doesn’t knock it loose, there’s the tab between the top bolts you can tap on, or use pinch bar/spacer on the tab to pry loose.

Don’t remember if I mentioned, but the boot to reedblock uses no gasket and relies on a raised rubber lip on the boot to seal. I usually put a thin coat of Hylomar on the lip to make sure it seals good. Any fuel resistant sealant should work. I like the Hylomar since it lasts forever and never hardens. 

Open that top end up :)

Can be intimidating at first, but once you see how easy it is, it’s really no big deal..

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Topend is disassembled. Everything in good shape as far as I can tell. I haven't completely taken apart the PV yet. I only opened the PV side cover to unclip the rod, so I can remove the cylinder.

Cylinder looks good and doesn't have scratches. PV seems to be working OK, just be moving the lever. Piston is the cast OEM I believe, and has lots of carbon deposit. Maybe some blow by on the side? Also no wear/damage on circlips, wristpin and needle bearing.

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Excellent!!!

It’s definitely time for a piston/ring replacement. 

Looks like you’re not the first one to have the top end off, not that it matters. The front PV cover screws should have copper crush washers under the top left (adjustment knob side), and lower right screws. I see the top one is missing its washer. Pretty easy to forget where these came from during reassembly. 

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Finally took the rest of the bike apart.

Reed valve looks good I think. Also took the stator cover off. No loose screws and also no oil inside the cover. Flywheel has no up-down play, so crank bearing should be good.

I took your advise to use a propane torch for disassembling the PV. Came apart pretty easy with heat. The PV was pretty gunked up with oil residue, but now damaged parts. Just needs a good cleaning I think.

What's the best place to order the Wiseco top end parts? Saw that the Wiseco piston kit on RockyMtnATV much cheaper than ordering from Wiseco directly. And are the Cometic gasket sets any good?  

These are the top end parts and gaskets I found on RockyMTVATV. Would they work for my top end rebuilt?:

 

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Well that’s good news!! You’re one of the lucky few to not find a bunch of loose PV screws:)

I’d still recommend removing the round castle nuts and Allen bolts on the secondary PVs and loc-titing them with “high temp” loc-tite. It’s when those come loose that the carnage begins. 

I never had any luck finding the correct tool to fit the 4 slot castle nuts. A straight edge screwdriver just buggered the tops up, and you obviously don’t want to use any pliers with ‘gripping teeth’ to avoid marring up the sides, since the nut is used as a stopper to prevent the valve from dropping into the cylinder. Both my bikes have replacement secondary PVs which have 2 slot castle nuts (and shorter Allen bolts that don’t obstruct the slots) 

You might try a small pair of these;

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This is what I used the get the nuts off my new replacement PVs so I could loc-tite. (Before I found a sawz-all blade fit perfectly in the 2 slot nuts) Love these pliers!!! Smooth jaws, and grip incredibly well. Just be careful how hard you squeeze the grips with these and let them slip a bit while turning, otherwise they might squeeze the nut oval. Definitely use heat, but try and focus just on the nut at first.

 

Looks like you do have fairly new Boyesen ‘Super stock’ reeds, but also kinda looks like they have a bit of a gap on the tips. Might just be the camera lens, but looks as though someone might have tightened the screws up too much, crushed the reeds, and warped the rev-plate. When tightening these screws there’s tight , then there’s “whoops” too tight. lol. Just snug, and clean ‘blue’ loc-tited threads :)

 

Haven’t heard any bad about the cometic gasket kits. Most likely it will come with a 1.5mm composite head gasket. Although spendy, I prefer the OEM Multi-layer Steel (MLS) “optional” 1.2mm head gasket. Stock these bikes come with a 1.7mm. The thinner gasket gives it more compression, and a bit more power. 

 

Not bad prices considering the time of year (part prices seem to go up in summer)

Here’s a complete Wiseco kit that includes everything. 

https://www.ebay.com/itm/Wiseco-Top-End-Piston-Kit-67-00-PK1339-for-Suzuki-RMX250-1993-1998/321589668890?epid=171268078&hash=item4ae03cec1a:g:dZ4AAOSwJQdW-aSl&redirect=mobile

Or for $10 less, there are a couple “open box” listings. 

Have one of these kits myself. Head gasket is 1.5 composite. Only problem I can see with the gasket kit is the exhaust O-ring is (cross sectionally) round, where OEM is oval.

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Gorgeous bike to the OP..!

Jealousy prevents me from being happier for you...lol...

DeVol made front radiator guards and Works made protective radiator braces...

I scored DeVol radiator guards and rear disc protector for my 97 off of ebay ... 

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Thanks for the info.
I got the Wiseco piston kit and Cometic gasket set.

Fully disassembled the PV, cleaned everything and put it back together. (Red loctite on PV nuts, blue on all other screws). With new secondary PV springs and new nylon PV rod clip.


Also installed the new Wiseco piston, rings, wristpin and bearing and fitted the cylinder. All looks good so far. Ring gap of the new rings was 0.35mm

I also cleaned and loctited the two stator screws.
Still need to put the head back on tomorrow and then put everything else back together. I’m gonna use the cometic composite head gasket. Measured 1.6mm thick.

If everything goes well I might have the bike back together and running this weekend.

My kick starter was also stuck on the splines when I took it apart. Should I file down the shaft or kick starter a bit before reinstall?


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Awesome. Looks great. :thumbsup:

Yes file down the sharp edges on the shaft. If you ever remove the side cover remember to wrap some tape around the splines before removing. Those sharp edges really do a number on the seal. lol :)

 

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Looking great!

Don't use that head gasket!

Grab one from an 89 RM250...

About .015" thinner and a nice bump in compression..!! Sharper bottom end response... A touch more power everywhere...

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