Pretty simple questions on pistons on 2 strokes?

[twistedkeys]

If you already know where another thread is, don't bother replying and just post a link ?

Anyway, I have a 1986 CR250, last owner of 3 years said that he didn't know anything about a "piston" or a "top end job" when I asked, @_@

Anyway, here're my questions:

Should I replace the entire top end?

Since I don't have money for a whole new top end can I just replace the rings?

Or should I ride it until I get a job?

Basically, since I can't get a new top end, should I even bother getting new rings? Or would it be a waste of time?

[Blake 888]

tear it open, inspect everything,

[twistedkeys]

tear it open, inspect everything,

And if everything looks fine.....need nothing? Or new rings just for the hell of it?

[SuperChief]

https://www.thumpertalk.com/forum/showthread.php?t=981942

I would get a job before tearing into the motor. This is not a cheap hobby by any means.

[twistedkeys]

https://www.thumpertalk.com/forum/showthread.php?t=981942

I would get a job before tearing into the motor. This is not a cheap hobby by any means.

Well I have a few bucks for new rings if needed, but what I'm asking is would it make any extra life on it at all? Because I don't want the whole damn cylinder to blow when the piston goes...

[matt 2778]

Do a compression test. I wouldn't recommend do a rering on a piston with unknown hours in fact I personally wouldnt do a rering. A broken piston skirt will destroy both the top and bottom end.

[twistedkeys]

Do a compression test. I wouldn't recommend do a rering on a piston with unknown hours in fact I personally wouldnt do a rering. A broken piston skirt will destroy both the top and bottom end.

Yeah. Piston looks perfectly fine from the exhaust port, but for all I know that doesn't mean shit ?

[B Lamb]

https://www.thumpertalk.com/forum/showthread.php?t=981942

[dgcars]

If you can't afford to do a top end, then don't ride it until you do. If you continue to put more time on the motor and it blows, it's going to be a whole lot longer without a bike. Putting rings into it, at this stage, is just a waste of money.

[William1]

With an 86, I'd do a leak down test. Check the status of the crank seals, reeds also.

You can never go wrong with fresh rings though upon opening, you never know what you'll find.

Do you feel lucky, do you?

[cwf340]

Is it hard to start? If it starts in the first few kicks then I would leave it alone. If its hard to start then yes replace the rings at the very least. Also keep the air filter clean. Clean and reoil it after every ride.

[tribalbc]

Is it hard to start? If it starts in the first few kicks then I would leave it alone. If its hard to start then yes replace the rings at the very least. Also keep the air filter clean. Clean and reoil it after every ride.

Finally some logical advice.

You would think from reading alot of the posts that every bike is just a ticking time bomb.....

How do you guys even ride worrying something could be wrong with your bike????

I'm all about maintenance, but you also have to draw a line somewere or all you are ever doing is replacing parts and not riding. And RIDING is really what it's all about.

[cwf340]

Finally some logical advice.

You would think from reading alot of the posts that every bike is just a ticking time bomb.....

How do you guys even ride worrying something could be wrong with your bike????

I'm all about maintenance, but you also have to draw a line somewere or all you are ever doing is replacing parts and not riding. And RIDING is really what it's all about.

Same here, I read so much about checking valves and replacing topends. My 07 crf450 still starts in the first few kicks. It has close to 70 hours on it and Ive yet to check the valves. But I keep my air filter clean and the oil changed religously. Just ride!?

[MrBlahh]

I dont think the OP is gonna have the equipment to do a leakdown test

it's very easy to teardown and visually inspect

[dgcars]

Same here, I read so much about checking valves and replacing topends. My 07 crf450 still starts in the first few kicks. It has close to 70 hours on it and Ive yet to check the valves. But I keep my air filter clean and the oil changed religously. Just ride!?

Yeah, I hear ya on that. ?

My point was.....if the guy has just bought a 25 year old bike from a guy who hasn't looked at the top end in the 3 years he owned it, I didn't want to be the one who says, "go on and ride it if it starts ok". He really should (at least) do a visual inspection of the motor internals before he goes any further. I'd rather strip a bike I just bought and find a cracked piston skirt than ride it and find out it needed a piston when the thing coughs alloy out the exhaust port.

Just my thoughts.....

[twistedkeys]

Is it hard to start? If it starts in the first few kicks then I would leave it alone. If its hard to start then yes replace the rings at the very least. Also keep the air filter clean. Clean and reoil it after every ride.

If it's freezing, it takes about 4-6 kicks. If it's warm, it takes one gentle half kick.

[twistedkeys]

Finally some logical advice.

You would think from reading alot of the posts that every bike is just a ticking time bomb.....

How do you guys even ride worrying something could be wrong with your bike????

I'm all about maintenance, but you also have to draw a line somewere or all you are ever doing is replacing parts and not riding. And RIDING is really what it's all about.

I know seriously! This bike is old sure, but it's a tank.

[twistedkeys]

I dont think the OP is gonna have the equipment to do a leakdown test

it's very easy to teardown and visually inspect

That would be correct! I'm one of those "ya only need WD-40, duct tape, and pliers!" guy when it comes to me being poor. Otherwise, EVERYTHING has to be perfect!! I'm a little weird ?

[twistedkeys]

Yeah, I hear ya on that. ?

My point was.....if the guy has just bought a 25 year old bike from a guy who hasn't looked at the top end in the 3 years he owned it, I didn't want to be the one who says, "go on and ride it if it starts ok". He really should (at least) do a visual inspection of the motor internals before he goes any further. I'd rather strip a bike I just bought and find a cracked piston skirt than ride it and find out it needed a piston when the thing coughs alloy out the exhaust port.

Just my thoughts.....

Any tips on a visual inspection? And how to stop the coolant spraying INTO YOUR FACE from the cylinder?!?!

[dgcars]

Any tips on a visual inspection? And how to stop the coolant spraying INTO YOUR FACE from the cylinder?!?!

Hey..you post on a public forum for advice. What did I say to deserve your disrespect. Sort out your juvenile attitude first - sonny. ?