Just bought another 250R ($800), but I have a question

[clong]

Ok guys, I just bought another 250R I found on orange county craigslist. Its a a nice looking R (see pics). The seat is stained, but otherwise its all there. I also have a another 1985 250R thats a low hours unit I paid top dollar for. So now I am comparing the 2 trikes. When I start both engines and analyze the difference in sounds, I notice my $800 250R at cold idle makes this occasional weird knocking sound and when it happens you can almost feel a the kncok make a jerking vibration all the way through the handle bars. If I rev the throttle at ildle, when the RPM's come back down, it does this "pang pang pang" and it makes a hitting sound you can feel. After it warms up it mostly goes away. The gas is 7 months old and I don't know the octane. I need to change that, but I'm thinking serious piston slap. The guy claims I bought it off of put a Weisco piston in it, but who knows if he telling the truth. Is this piston slap I'm hearing? Am I looking at a possible grenade if I don't change out the top end? I like this bike and don't want to blow it up.

[DeePa]

check the plug and see if the piston has hit it at all. Head might have been shaved.

Since it was 800 bucks, and looks more like a 1300 trike....you have two options.

It was cheap. RUn it and see what happens. If it blows, it blows.

Pull the motor, spec everything out, rebuild bottom and see how top end is.

Mike

[Dirtcrasher]

There are still a ton of 250R's out there with stock pistons and cases that never got cracked open.

One of the very common failures on the R's was the counterbalancer. A few things happen - The bearings go, the bolts come loose and the left bearing holder breaks.

By taking off both the left and right side covers you can check out those points, the clutch and the main bearings too, At least then you'd feel more comfortable about the noise.

[Hoosier_Daddy]

from my experiences with Honda, that sounds like a rod bearing. But the advice above is very good.

[clong]

What exactly is a rod bearing? Is that the bearing at the base of the crank or the bearing at the top of hte piston? I'll do a top end if I have to, but I'm not splitting cases....1 becasue I don't know how and 2, becasue if I pay someone, it will cost more than the trike is worth. Should I just run it and see what happens. If she blows, its worth $500 in parts maybe being all OEM plastic no cracks and in pretty good shape.

[fabiodriven]

Not only would you be splitting the cases, but you'd be splitting the crank! That's about as much splitting as you can do! I'd try fresh gas first, and could be jetted wrong. My Tecate 250 used to make some pretty mean pings before it was jetted right and got new crank seals. BTW, that's a damn score for 800-

[clong]

I'm going to go through the jetting tonight and put it all back to stock. I'll also drain the gas (it smells varnishy). I'll clean the air filter, put a new plug in it and see how she does. Based on the overall good condition of the trike and it sits original tires so it can't be overly worn internally, I can't see anything major being wroing with this thing. I'll update in the morning.

['83 250R]

if i lived in CA i would buy that for $500 so fast even being blown up in NH they sell for like 600-750 locked up with no plastic and cracked cases

[Taiser]

Another guy with a great find....cry!

:D

[fabiodriven]

if i lived in CA i would buy that for $500 so fast even being blown up in NH they sell for like 600-750 locked up with no plastic and cracked cases

You ain't kiddin! I'm in the same boat! (south of Boston)

[Dirtcrasher]

It doesn't matter how it "looks". That doesn't mean it was babied, the oil was changed or the air filter got cleaned. Change your jetting and your gas etc etc but I'll just tell you that I got a similar mint find where the owner had passed away. As incredible as it looked, the motor needed a ton of work. Play in the crank, play in the mains, broken counter balance bolt and a very worn cylinder/piston. Was it fast? HELL YA!! but it was tired, veeeery tired and although I could have ridden it, I rebuilt it so I didn't have to worry about it..............

[Mosh]

Well,Good deal on it.It looks pretty clean.
Your problem with the knocking.....

Mine was doing that.When it revved down back to idle,you could feel a "slap" in the left foot peg.I pulled the stator cover,and the left main bearing was loose.You should have NO movement up or down or, in and out in the flywheel area.If so,the main bearings are toast.
Counter balancers are also a issue on the 250r waterpumpers.But I hear them growl before they get bad enough to vibrate.
Knocking and slapping you can feel,is not good.I hope I am wrong,but you may need to put a crank in it,and or bearings.

[sunblock]

That is a great deal, even if some rebuilding is needed. I would jump on it in a heart beat. I do not know much about the specfics of the motor but all the advice above sounds good to me. I would at least change all the fluids, clean out the carb, look at the air filter, check the jetting, and put some good 2 stoke oil in the fresh gas before I did anything else. If you are worried about piston slapping or other problems you can pull off the pipe and look up the exhaust port to get an idea of the piston and cylinders condition.

[J.D.]

Ok guys, I just bought another 250R I found on orange county craigslist. Its a a nice looking R (see pics). The seat is stained, but otherwise its all there. I also have a another 1985 250R thats a low hours unit I paid top dollar for. So now I am comparing the 2 trikes. When I start both engines and analyze the difference in sounds, I notice my $800 250R at cold idle makes this occasional weird knocking sound and when it happens you can almost feel a the kncok make a jerking vibration all the way through the handle bars. If I rev the throttle at ildle, when the RPM's come back down, it does this "pang pang pang" and it makes a hitting sound you can feel. After it warms up it mostly goes away. The gas is 7 months old and I don't know the octane. I need to change that, but I'm thinking serious piston slap. The guy claims I bought it off of put a Weisco piston in it, but who knows if he telling the truth. Is this piston slap I'm hearing? Am I looking at a possible grenade if I don't change out the top end? I like this bike and don't want to blow it up.

Could just be the piston. Forged pistons(at least in vehicles) will have a little slap until they get warmed up to operating temperatures. Definately wouldn't hurt though to pull it apart and check it out.

[clong]

Ok last night I did allot of work to this thing. I pulled the carb and this carb was set vbery lean so I richened my settings. I pulled the head pipe and the piston has no scoring and looks good to the common eye at least. I cleaned the air filter and changed the plug. I drained the gas and boy was that gas old. I put fresh in it with premium and alittle octane and Yamalube. I fired it up and did not have any significant knocking. Its definatley running allot smoother. Its a hard call to say its all fixed but from what I can tell last night, she is smooth. I'm going to continue to keep an eye on it. Thanks guys.

[Taiser]

Sweet...sure you'll enjoy it!

[clong]

I forgot to say thanks guys for the props on this buy. Even though it may or may not need some work, thanks for the thumbs up. Anytime you spend cash, its nice to feel supported.