old cr250 question.

Hi guys, I'm thinking of picking up a buddies 1986 cr250. Apparently it's engine was rebuilt about a month after it stopped working. He wants 500 bones for it but I'm not sure cause the engine won't run. It has a pipe and some other stuff done. The engine put out 60 psi on a compression test after a few kicks. I don't know if that's good or bad. There is a spark but my buddy thinks it's weak.

If you think that the 60 psi is bad or that this is going to cost a fortune, let me know. Thanks guys.

60lbs is way too low. If I remember correctly the 250's should be in the 150 and up range. Someone can correct me if i am wrong.

If it truely had a top end and it is still reading that low, I am not sure what else could be wrong. Possible bad gaskets or lower end seals.

60psi is a no go.

I'd want to look inside it before I potentially threw money away. You could end up spending a large chunk to put it back to running condition. It might need everything top and bottom, ignition parts, linkage, etc. I've seen those shocks get belled-out (worn out like the bore in a cylinder) and need complete replacement - not cheap.

And even then you'd still wind up with a 20 year old bike.

Might want to save that money and put it towards something a little newer and more sound.


Yeah I think I may have goofed on the PSI. It may have been more Either 60 or 140psi. If it's 60 forget it but if it has the proper compression should I do it?

re- check the compression, just to make sure you did it right. the spark should be blue, and you should hear it snap! if everything checks out ok, and it still wont start, check that it is getting fuel, maybe the carb is all gummed up from sitting.Is it a fresh bore? If not the piston will probably just break again. If it all seems ok and you can get the bike running, give him the 500 bucks he's asking and have fun! where else can you have that kind of fun for that kind of money? Playstation will cost more than that, and it's boring!

Check the water pump housing for erosion. Coolant left in too long has left a lot of those old bikes with ruined right crankcase covers.

Thanks for the help guys. I haven't checked the compression yet but when you kick it over you can feel the compression build up nicely. Before I came to look at it my buddy said he kicked it over 6 times and got 155psi. It's in a few pieces as he was trying to get it running. The fuel lines not connected to the carb, seats off just little things like that. He did say that when he puts ether into the engine it usualy fires up for a bit. He says that didn't work for him do he's suspecting it's the spark. I've had no time to diagnose it but I'll probably start tommorow. Any suggestions?

Oh yeah It's a 1985 cr250R I thought it was a 1986 and I'm not sure what the "R" really means but it has no key for the ignition and no kickstand either. It's leaning on my crf150 in the garage right now. Gosh the difference in height isn't much but it's longer and the rear tire is like twice the stock size on my crf. I can't wait to open this bitch up!

Hey mate, I used to have an 85 CR250 years ago, mine was pretty stuffed and I ended up snapping the frame in half but otherwise not bad bikes.

Check the coil resistance as when I had an electrical prob on mine the coil was stuffed.

The R stands for Racing, it is a full blown MX bike with nothing but the absolute essentials, there was never any ignition barrel or kickstand fitted to it.

That year model was specifically known as the CR250RF


Thanks for your help man, that clears up why the stuff is missing. I'll have the bike running really soon but I do have a bit of a problem with the plastic on the bike. I wanted to try and find a plastic company to ugrade the look of the bike to a newer model.Possibly even changing the colour of the plastic. What if this bike is rare. Should I try and keep the stock look?

An 86 is a great bike,you can more than likely put a 87 CR 250 or 87 or 88 CR 500 swing arm on it with a rear disc and you have a bicthen machine!

Hello again, I think you will probably find that no platic manufacturer will still make aftermarket panels for you bike, your best bet will be for NOS, secondhand or repro fibreglass panels.

Its not exactly a rare bike, but there will be very little after market gear for it because of its age.


hey do you know anything about Honda CRF250R?

The CRF250 has its own forum mate. Have a look in there :thumbsup:

hey man,

check out www.ericgorr.com this site has tons of mechanical info about old cr250's and such. rockymountainatv.com might have the plastic you are looking for.

Yeah I sent the bike out to honda where I bought my CRF. They charged $90 to try and get it running. The spark was fine but they said the compression would jump to 130 then to 0. They said it needed a top end job to get it runnning. They were also nice enough to tell me it needed 940 bucks just in parts to have it all fixed A-Z. It needs a chain and sprocket, wheel bearings, shock bushings, etc.

So I tore the top end off and the piston melted itself to the rings just under the arrow side. The jug and piston are at a shop. The told me they can most likely hone it and hook me up with a piston for about $250 including the gaskets.

I can't wait to get it running. The power valve is funny though. I pulled it off but I don't know how to put it back in. Do I put it back in with the valve open or in the relaxed ( Closed ) position?

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