Hey Guys I have hopefully found the problem

[runutz698]

Hey guys,

Just an update on the fast reving 2-stroke disel lol I am pretty sure i have found my air leak, The crank seals that someone has used are not the right size, I can push the seal in out of the holder with my fingers and it doesn't seem tight around the crank, These are standard CSC seals I rember someone saying that they are an odd size and that they couldn't buy them off the shelf. so fingers crossed if it is not this it is leaking in the centre of the cases. I have ordered some off the ever realible Jared and will have my answer by the end of the week.

Cheers
Tom

[TooFastTim]

Might be an idea to order a case gasket from Jared and lap the case faces while you're at it. It would get rid of that variable.

[runutz698]

I am trying not spit the cases if this doesn't work then the cases will need to be split I have inspected it all the way round and the gasket is all there and looks soild. So we will see how we go.  But cheers for that. I know the Flywheel was a bitch to pull off I am still waiting for my magic puller from Jared as I broke 2 pullers already, Everyone was saying these have a habbit of falling off. LOL
Cheers
Tom

[cappra]

If you have broken two pullers already, that's a bit scary!
Be sure to lube the puller's threads and make sure the centre
part is backed off all the way and tighten down the puller good.
If the main seals you removed were any other size than 30 x 50 x 10mm
then that was most likely the air leak problem.

                                                            Jared

[cappra]

Tell me you were not using a jaw style puller around the outside
of the mag.  :'(

[runutz698]

Jared 2 pullers it wasn't the thread it was chinese casting crap wherre had boken there was massive air bubbles in the casting. I never had a problem getting things off in the past, I pulled the XR75's Flywheel off with the same puller and it worked a treat all back togeather and running so sweet. Oh well the correct one will do the trick.

I will measure the seal but there was oil on the outside of the seal retaining plate, so it was def. leaking.

Cheers Tom

[TooFastTim]

Mag should come off ok. It's the primary drive side that gives me the willies. Took it off a 349 once. Lots of grunting and groaning, nada. Eventually it was out with oxy-acytelene. BANG! Two of us running for cover screaming "where the f&#$ is it".

[runutz698]

Well the seals apon inspection are the right size but seem sloppy in all directions, so I whiped out my handy dandy calipers to measure and they seem small in all directions, should they be tight in the holders as I can push the ones I have in and out with my fingers???

The bike has been sitting for sometime after rebuilding!!! So it could be that they are old dunno, I have a feeling that there from a guy who use to sell montessa parts in Aus, I think he does truck driving or something now as I tried call hime when I started my resto. I belvie he still has lots of parts.

Cheers Tom

[mx250]

Well the seals apon inspection are the right size but seem sloppy in all directions,

is the steel insert the right size? The neoprene may have shrunk if exposed to fuel/oil.
 

should they be tight in the holders as I can push the ones I have in and out with my fingers???

Sounds too loose. Mine you have to pry out with leverage. I would guess wrong ones.

The bike has been sitting for sometime after rebuilding!!!

If it hasn't been fired up or they weren't doused in oil during assembly, they should be as good as the day they went in.

I have a feeling that there from a guy who use to sell montessa parts in Aus, I think he does truck driving or something now as I tried call hime when I started my resto.

Advertised as Montesa World in VMX IIRC. I tried and couldn't contact him.

I belvie he still has lots of parts.

If he has he arn't sharing .

[cappra]

The main seals should have to be driven (use the old seal) into the holders
with low to medium force.  If the old ones are not dual lipped or bluish
green in colour, then they have been replaced at some time.  Be sure to
oil up the new seals on the inside and out to aid in installation.

TooFastTim,
Joyfully, the 77 and later mxer's have a splined primary side, as well as countershaft.

[runutz698]

The seals are double liped(second lip seems smaler) but are blue in color, They look to be a good seal (no obvoious cracks) but don't not fit the holders properley I am ok with the inside dia being smallers as it will be a snug fit on the crank. I

 will wait and see if the ones you hav sent me Jared will do the trick, They also seem alot more that 10mm thick like 12+mm so I am guessing they are close but no cigar. What ever the air leak it must only be slight as if it was a big air leak it wouldn't of started first kick with no gas(after sitting for 10years+). Big air leak would make it a bitch to start. Oh well wait til I get the puller aswell as the otherside might be the wrong seal...

Cheers for your help guys.

I also belive there to be a couple in SA with shipping containers full of stuff for monties, the guy up north told me he has parts in a shipping container but is not intrested in dealing anymore.

Tom

[mx250]

I also belive there to be a couple in SA with shipping containers full of stuff for monties, the guy up north told me he has parts in a shipping container but is not intrested in dealing anymore.

I don't know about SA but I was dealing with an Ebayer at Inverleigh in Vic who claimed to have several containers of Monty stuff, and importing regularly. Talking on the phone he was suppose to be a VMX'er, Monty owner and restorer, and a Twin Shock rider/restorer, and all round good guy and keen motorcyclist. If it's the same guy proceed with caution; I'm still trying to get $100 refund after a dud deal. I don't know if he is genuine or purposely stuffing me about. It been 3 months.

Things should come to a climax shortly, I should know if he is genuine or purposely pissing me about. I'll keep you posted.