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Rebuilt rm125 won’t run

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My 99 rm 125 was just rebuilt and the cylinder was resleeved I put it together and when I put coolant in it leaked out the head. I took the head off and the outside o ring got squashed, I replaced it with the old one and put the bike together. I put Castrol 10w-40 in the crankcase and put 34:1 in the tank. No apparent leaks except a little out of petcock that stopped. Harder to kick than before so I’m assuming good compression. I kick and kick and kick and finally with choke on it starts then dies, I kick some more and it starts but won’t idle at all, before it idled pretty bad now it just won’t, it runs for a little while with me giving a tiny bit of throttle then I let of gas and it dies. I go to bed and wake up today and try to start it and it will not start, choke on, choke off. I tried bumpstarting once and it ran I guess but dies immediately and didn’t truly run. I know it’s getting gas because if I give it a little gas when kicking you can hear the engine sounds different. It just won’t run, what do I do?!?

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Accurate cylinder sleeve works. A good reviewed company.

19 hours ago, mlatour said:

The bottom end is likely full of coolant.

How would the coolant get in there and how do I get it out?

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If the cylinder head o-rings leaked, 

coolant may have got in the cylinder and made it's way to the bottom end thru the transfer ports.

 

If you have the cyl. head off,

lay the bike on it's side or, upside down.

crank the engine over a few time.

 

If there are signs of coolant in the bottom end,

you may want to rince it out with diesel a few times.

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3 hours ago, mlatour said:

If the cylinder head o-rings leaked, 

coolant may have got in the cylinder and made it's way to the bottom end thru the transfer ports.

 

If you have the cyl. head off,

lay the bike on it's side or, upside down.

crank the engine over a few time.

 

If there are signs of coolant in the bottom end,

you may want to rince it out with diesel a few times.

Only the outer o ring leaked not the inner, it was because it slipped when I torqued the head bolts down and got squashed. The inner ring was fine. Doesn’t that mean it would stay out of the cylinder? The bike is completely together and ran ok right after assembly( after outer o-ring incident)then eventually died and wouldn’t start, would this happen if there was coolant in the crank?

52 minutes ago, ar2stroke said:

You many need to get a cylinder off EBAY and have it Re-Plated as that sleeved is most likely not goin to work.

It is a guy that’s been doing them for almost ten years on a lot of rms and yzs and all kinds of bikes and he doesn’t have any bad reviews. He has a big computerized machine that does it.

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If it was only the outer o-ring and no coolant was visible on the top of the piston during dis-assembly,

then there shouldn't be any coolant in the bottom end. :thumbsup:

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Some basic checks:

-no rags forgotten in the intake / reed block

-reeds not damaged

-was the flywheel removed, woodruff key fall out

-stator / ignition timing plate disturbed

-idle speed screw set too low

 

'I put 10W-40 in the crankcase', hoping you meant the gearbox

Edited by mlatour

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1 hour ago, mlatour said:

If it was only the outer o-ring and no coolant was visible on the top of the piston during dis-assembly,

then there shouldn't be any coolant in the bottom end. :thumbsup:

Ah ok, makes more sense now - once you get that fixed should be ok then.

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4 hours ago, mlatour said:

Some basic checks:

-no rags forgotten in the intake / reed block

-reeds not damaged

-was the flywheel removed, woodruff key fall out

-stator / ignition timing plate disturbed

-idle speed screw set too low

 

'I put 10W-40 in the crankcase', hoping you meant the gearbox

Yes I mean gearbox😂. I didn’t touch any of those things, I cleaned the carb but only a little when I realized it was clean already. I think I’ll just take it to a mechanic and see what he says when he can see and work on it. I don’t know what else to do

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Is gas reaching the spark plug?

 

 

Even if adjusted a tad low, that wouldn't keep the engine from getting sufficient gas to start and run at lower rpms.

If the level was too high, it would perhaps flood the engine and leak out the overflow tubes when moderately leaned over.

 

Are those RM pistons 'windowed' ? (piston port)

If so, confirm it wasn't installed facing the wrong direction.

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On 10/31/2018 at 11:48 AM, mlatour said:

Is gas reaching the spark plug?

 

 

Even if adjusted a tad low, that wouldn't keep the engine from getting sufficient gas to start and run at lower rpms.

If the level was too high, it would perhaps flood the engine and leak out the overflow tubes when moderately leaned over.

 

Are those RM pistons 'windowed' ? (piston port)

If so, confirm it wasn't installed facing the wrong direction.

Doesn’t spill when leaned over and gas in on the spark plug no they’re not windowed

 

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