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1986 cr125 Engine Catastrophe?

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Just bought a 1986 cr125 the other day. When I went to look at it it started and rode after maybe 10 kicks. It was a bit beat up but but not too bad for a 30 year old bike and since it ran and all the paperwork was up to date I bought it for $500 knowing I'd have to give it a little TLC. This is also my first experience owning a 2 stroke.

Today I went to change the coolant and when I went to drain it a thick gray liquid, roughly the consistency of yogurt, dribbled out of the drain hole. I poured a little coolant into the radiator to see if that would thin out the gray substance in an attempt to flush it out and it basically just sat at the top of the radiator. Bummer, I'm assuming my radiators are garbage now...

From there I took of the side cover to the water pump and was astonished to find the water pump area oozing with this gray stuff as well as there being a bunch of hard chalky white stuff caked throughout the water pump area. I can scrape it off with a screwdriver but it's literally all over everything and I was unable to get the water pump disassembled because of it.

 

I also noticed a chunk of the case is missing where the bottom of the water pump cover sits. Really not what I wanted to find.

 

I ended up pulling the engine and dismantling it a bit. I didn't necessarily see signs of a blown head gasket but the piston has some some damage and the top ring is bent and stuck on the piston.

 

I've heard horror stories of people using seafoam on bikes with similar white chalky crap gunking things up, so if that's the case then I'm assuming the oil and the coolant/water are mixing from either the head somewhere or a bad seal in the engine and that combined with the seafoam crud is producing the gray sludge.

 

Has anyone had a similar experience or any advice as to how I should approach this? Any tricks I could use to salvage the radiators, like a way to flush them out or a good antidote to seafoam?

 

Thanks

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This is some serious neglect but not all is lost.

It may look worse than it actually is. You might just need a few new seals (Oil and water) and a gasket kit which is only a few bucks . And a bit of love .If you don't have a service manual get one.

You will need to get another case also.

Edited by john torrisi
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First I don't see how you can hold any water in the system or create any water pressure with that missing piece. This is what an 86 water pump housing should look like, I I would think you need to start by replacing the the eight crankcase cover first. When yy have a leak in the pump bearing the coolant will mix with the engine oil to produce a really gray, milky substance. The stuff in your pic looks thinker than what the coolant/oil mixture will produce so my guess is that it's something they added to mask the problem or it is actually aluminum from the cases degrading... or both. You'll need to clean it out thoroughly and determine if the bearings, seals, and cases are worth saving.

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The clutch covers are made out of magnesium and corrode if left in contact with water. Honda went to a 2 piece aluminum cover in 87 which won't

fit our 86's. A lot of people use a epoxy to reshape the area where the impeller sits. I don't know how this holds up. There is a guy in the UK that made

some out of aluminum that had Honda Racing on the cover like the factory bikes they are around 700.00 us. You might be able to find a NOS or one

not as corroded on ebay. 

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Here's my largest concern at the moment. The case itself has a penny sized chunk missing out of it behind the water pump cover. If I were to be able to clean up the rest of the cases and rid them of the corrosion build up wouldn't this still be a deal breaker?

 

I'm pointing the area the case is chipped with a screwdriver in the pic.

 

Should I start shopping for new cases?

 

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If the top end is going to need to be machined, a new piston/rings needed, new water pump components needed, new cases needed potentially, as well as gasket, seals, bearings and whatever else required for overhauling the engine, would it make more sense to just look for a new engine in decent condition?

 

Would that be a cheaper way to go in the grand scheme of things?

 

And if I do go that route are there other cr125 year engines that I could use? That would give me more shopping options at least.

 

Thanks

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Concur completely with Lazerviking. You may even want to consider just getting another bike completely as this one is about to be a serious money pit. Are you interested in vintage? The person you purchased the bike from certainly doesn't appear to be the kind that takes good care of his bikes so chances are you going to run into other problems as well. If you could find a complete motor I would consider that if you're really interested in restoring the bike. Individual major components are expensive so think long and hard before you start pouring money into the bike.

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If the rest of the bike is in restorable condition, that would make a nice chassis to fit an XR200/250 or

CRF230F engine into and make a well suspended, good handling trail/off-road bike.

Edited by mlatour

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Concur completely with Lazerviking. You may even want to consider just getting another bike completely as this one is about to be a serious money pit. Are you interested in vintage? The person you purchased the bike from certainly doesn't appear to be the kind that takes good care of his bikes so chances are you going to run into other problems as well. If you could find a complete motor I would consider that if you're really interested in restoring the bike. Individual major components are expensive so think long and hard before you start pouring money into the bike.

 

You might be right. Damn. I just wanted a little beater bike to thrash around on some trails. I didn't want this to be a major project. I think I'll go through the whole bike and determine what needs to be replaced to get it ride worthy and then weigh that cost vs finding another bike.

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If the rest of the bike is in restorable condition, that would make a nice chassis to fit an XR200/250 or

CRF230F engine into and make a well suspended, good handling trail/off-road bike.

 

I was thinking the same thing but I don't know what engines would be compatible with the 86 cr frame and rear suspension. Would an xr200/250/crf230f engine be a straight swap or would I need to modify the frame and rear suspension? That's territory that I am unfamiliar with.

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I was thinking the same thing but I don't know what engines would be compatible with the 86 cr frame and rear suspension. Would an xr200/250/crf230f engine be a straight swap or would I need to modify the frame and rear suspension? That's territory that I am unfamiliar with.

The frame would need to be heavily modified. They way the two engines mount is comepletely different.

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