Engine strip and rebuild

ned37 · May 16, 2010

the sprague doesn't get shimmed, the torque limiter does, and generally only if its demonstrated that it slips early. its all in the doc.
if you kick it over gently with the plug out, is it easy? what about with the plug in place? does it stop at tdc compression?
what year and model are you dealing with? stick it in your signature.
and ya, cold oil does make a big difference.

abclint · May 17, 2010

Hi guys,
The bike was running fine, after the race it was cleaned and left for 2 weeks.
When trying to kick start, the motor turns over as it should but is a ******* to start. On electric the sprague just spins.
The oil colour after one race was a muddy colour. There are no bits in the oil other than the usual tiny flakes.

I will try a lower viscossity oil 10w40 to try and start it. If it works then I know it's the oil.

Coastie · May 17, 2010

Wadda mean the oils looks a muddy colour?
No oil should look muddy!
Should look somewhere between nice new oil and old black oil - nothing else.
Sounds like you've got some coolant mixed in there.
Drain the muddy stuff and check it out.

abclint · May 18, 2010

Checked, all the seals where replaced and are still good. I put the oil in a glass jar overnight to see what settled. The crud in the bottom of the glass is like a brown paste. There is no water at the bottom.
When kicked over with the spark plug in place the engine only does one revolution and does not stop at TDC. Is there extra friction in the engine somewhere that would cause this and the sprague to slip?

Coastie · May 18, 2010

abclint said:
When kicked over with the spark plug in place the engine only does one revolution and does not stop at TDC. Is there extra friction in the engine somewhere that would cause this and the sprague to slip?

Don't understand what you mean?
If you turn it over slowly you should feel it get progressively harder as the piston comes up on compression and then after you've gone past TDC it will get easy. Do it a few times and you'll feel it go over the hump which is TDC.
If the decomp systems are working and setup correctly it shouldn't be hard to kick over and I'd even say it's sometimes difficult to tell when it's on compression with your foot. If the decomps aren't right then it's phuggin hard and the leccy leg prolly won't be up to the job for long if at all.
The rest of the stroke should be free as it's only against the valve springs.

How does it feel when you take out the plug and turn it over?

PS. Personally I'd still be worried about brown paste in my oil. How much are you talkin about? Sounds like oil/coolant mix.

Coastie

abclint · May 19, 2010

Well I spoke to Taffy about this and he reckons, head gasket for starters. Another complete strip down yeehaa

abclint · May 20, 2010

Going to do a complete overhaul. Does anyone know where I can get a crank case-puller 270011-01 so I can get started.

Cheers.

Taffy · May 20, 2010

just whack it with a copper hammer on the inside faces of the rear swing arm shoulders. that will prise the cases apart at the back and then you're in. make sure you don't pri and pry them apart at the waterjacket.

and don't forget the bolt in the MIDDLE of the cases behind the ignition cover....

regards

Taffy

abclint · May 20, 2010

Cheers Taffy,

I sent you an e-mail for parts. I will give you a ring latter.

ned37 · May 20, 2010

I will give you a ring with card number ect..

just print it here. its ok, this site is secure (don't forget to leave the exp date and # on the back, too) :cheers:

Coastie · May 21, 2010

abclint said:
Going to do a complete overhaul. Does anyone know where I can get a crank case-puller 270011-01 so I can get started.

Cheers.

You can use a 3 leg bearing puller if you've got 1. Just put the 3 ignition cover bolts in the case, put the legs behind the boltheads and wind down against the crankshaft.
Put a little bit of pressure on it and then do like Taffy says and bash the back where the swingarm goes thru with a soft mallet. Should come apart pretty easy.

Taffy said:
and don't forget the bolt in the MIDDLE of the cases behind the ignition cover....

Hey Taffy

Sounds like this is from experience ???

Coastie

abclint · Jul 27, 2010

Got the bike running sweet and then this happens in mid air. Not good.

abclint · Jul 27, 2010

Now I have found this and I have no idea where it came from. Any help would be good.

philis · Jul 27, 2010

abclint said:
Now I have found this and I have no idea where it came from. Any help would be good.

Thats a 20p peice, probably fell out your pocket.

Taffy · Jul 28, 2010

it's one of the 4 bearings that hold two parts with one shell needle roller at each end.

the starter clutch
the sprague

have you recently removed all the starter kit?

regards

Taffy

abclint · Jul 28, 2010

I replaced the Sprague complete a while back. I just found this on the the bike paddock service stand. I will look at the old sprague to see if it's missing from there. If not then off comes the clutch cover again.

Cheers Taffy.

Coastie · Jul 28, 2010

Dunno how big that coin is but isn't that a cam chain roller?
Is the chain in 1 piece or many?

I think Taffy is talking about the needle roller bearings in the cases.
But for those to fall out you'd have to have no shafts holding them in like if you took the starter clutch out but sounds like yours is in there.

Taffy · Jul 28, 2010

coatsie I think you are right! and that isn't a crack that's a split roller at 2 'o clock.

that really DOES look like the needle roller but the split is the giveaway!

regards

Taffy

The_Force · Jul 28, 2010

could it be a DOWEL 6X8X11,5 for the clutch cover or something else?

abclint · Jul 29, 2010

You are right, Its just over 6mm wide and it does have a split down the length of it.

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