86 RM250 issues

[Tony Two Times]

Well it's been an interesting couple of days.

Got the seal. Fitted it no dramas. Put it all back together. Same problem - oil out of the exhaust.

Pulled it all apart again to check the seal. (Lots of) coolant in the oil. Checked the seals on the water pump and they were hard as nails and cracked. I figure removing and fitting the case cover moved one of the (24yr?) old seals enough for it to give way. Get new seals from BSC for $5 each (so much for going to Suzuki), chuck 'em in, button her up, and give her the boot.

Same problem - oil our of the exhaust. Remove the oil filler plug while she's running per earlier suggestion and she revs like a zirtec suggesting she is sucking air (and oil) through the new seal !!

So all I can surmise now is that the crank shaft is worn or grooved and not forming a tight fit with the new seal. Don't remember seeing any obvious wear when fitting the new seal but I've got the whole dissasembly process down to a 20min exercise by now, so it will all come apart again for another look.

Pressure is off now though as this weekends VMX meet is a goner as I won't have time to sort it by then.

Old bikes hey ? Gotta love 'em 

T2X

[smed]

G,day Tony,have you looked at a Suzuki parts diagram to see if anything is missing,some bikes run a thin oring on one end or the other of the collar that goes on the crank before the primary drive gear,also is the collar the correct one or bodgy?or as you said grooved?, no main bearing movement?worst case scenario cracked or porous cases?

[DR]

in regards to the seal you can tweak them a little by slipping out the spring and twisting it a few more turns before refitting. Obviously don't go winding it in too much or it will be overtight on the shaft and it'll wear the seal rapidly

[suzuki27]

Couple of things worth checking. I don't know about the 86, but up until 84 you will need the new ceramic washer on the water pump shaft as well as the seals. If it is leaking here ,and it is a common problem, the main seals on both sides might not seal due to corrosion/rust/pitting etc on the crankshafts.I have had to have 2 125's crankshafts replaced(resurfacing is an option) due to this.
If they are leaking here you can also get oily build-up in the stator/rotor area due to it blowing through, as well as the "milky oil" etc. Probably worth getting the chamber de-coked and re-pack the muffler.

[Bikeaholic]

Hmm sounds similar to what happened on my RM250X (81) Fouled plugs running like a dog, oil dribbling out the header pipe. Suspected crank seals but ok. Then thought perhaps the centre case gasket had gone and sucking gearbox oil via there. Split engine and found steel inserts in cases for the mains loose on clutch side. Oil was getting sucked in past the insert. The originals have dowls that locate the inserts to stop any movements. Mine had copped the center punch treament at some time to tighten them up. Apparently a common problem with the RM's. I used another spare set of cases that had aready been modified with new inserts and fixed the problem. Still have to do the mod to the originals. Don't know if the 86 has the same inserts but worth checking all the same. No noticable loss in gearbox oil while this was going on either.

[Tony Two Times]

Well last minute change of heart on Saturday morning. Pulled her apart to check and reassemble her one more time. In my frustration I *may* have had the sleeve behind the cog on the crank back to front.   

Checked the parts diagram. Turned the sleeve around and put it back together. Still blowing some oil but not too bad. Decided to go and ride the QVMX round anyway and bugger me if she didn't all but stop the problem during the course of the day. I figure there may have a little oil left in the zorst and header but as the day wore on she was all good.

Thanks to everyone for the tips and advice. It's been a frustrating but educational couple of weeks. All worth it !!

Big tip - never understimate the stupidity of the bloke with the spanner in his hand !!

T2X

[whitey 43]

Hey Tony, was that you I seen go A.O.T near the top of the hill on Saturday? Sounded like it had A stuck throttle too...Was nice to meet you on Saturday, catch up soon.

[Tony Two Times]

Nah man I managed to stay in the saddle all weekend. Had a couple of brown trousers moments yesterday when I got my ambitions and ability confused but held it together thank christ.

Yeah good times mate. See you at the next one on a 250 maybe!!

T

[whitey 43]

I'll be there, caboolture isn't it?

[RMJJ]

Good to hear its sorted  but you should never get coolant in the gearbox.
The coolant should come out the relief hole under the pump.
Has someone blocked it up ?