Killed my top end?

[crackshot]

I was running my R today real hard and riding in 4 feet of powder dirt.
The trike was running good then seemed to get real hot. I had to plow through this dirt WOT. I know I was red lining all the way up and down this hill. This dirt was worse than sand.
I continued to it up the dirt hill a few times then just died.
Engine was extremely hot to touch.
I managed to get it running again and rode it home a mile and died again.
Swapped spark plug and got it home.

Now my top end sounds real noisy and won't idle.
Have I killed my top end?

[slothminx]

Yes, WOT with low airflow, you over heated it.


Maybe the oil you run. j/k

[crackshot]

Yes, WOT with low airflow, you over heated it.


Maybe the oil you run. j/k

Haha about the oil. I don't think any brand oil could have survived this hill.

Guess its tear the top end down time!

[200xcellent]

maybe a shift or two would have helped

[nate b]

Dude, if I did something that foolish I wouldnt tell anybody about it.
Sound like you pretty much purposly destroyed a running 250r.

[crackshot]

Dude, if I did something that foolish I wouldnt tell anybody about it.
Sound like you pretty much purposly destroyed a running 250r.

Foolish? You could only take this hill in 1st gear. If you let off the throttle, you would sink it. Don't tell me about running hills, sand, trails.
I have been riding since 1975 and ATC's since the early 80's.
This is the FIRST 2 stoke I have cooked. BTW, I did not PURPOSELY kill my ride. I pushed it to the limit and it could not handle it. Plain and simple.
It still runs but just noisy. When I bought it, I did not know how much life was on the top end. Thanks ok though, Parts are on the way and if worse comes to worse, I will scab it back together and buy a quad. 450's looking pretty tempting these days.

[hrc85250r]

well, when its sitting there idling and you gas it will it rev up? if it wont rev up and just bogs you could have a small hole in your piston, but it sounds like you just torched your crank. i recommend pulling the top end off and checking things out, especially the crank, make sure it rotates easily and doesnt feel at all "rocky" and the rod doest move side to side very much. if your sketchy about judging the crank for yourself take it to a good shop. its not worth letting the rod let go or the mains. a 100$ for mains and a rod kit is a lot cheaper than 250 for them plus a piston kit and a bore job after she pops her cookies. oh yeah, and word of advice...unless its a race motor, it isnt designed to be run WOT for more than 10 seconds at a time. and if you feel the motor getiing hotter and hotter, stop and let it cool down. crazy bastardo!

[crackshot]

well, when its sitting there idling and you gas it will it rev up? if it wont rev up and just bogs you could have a small hole in your piston, but it sounds like you just torched your crank. i recommend pulling the top end off and checking things out, especially the crank, make sure it rotates easily and doesnt feel at all "rocky" and the rod doest move side to side very much. if your sketchy about judging the crank for yourself take it to a good shop. its not worth letting the rod let go or the mains. a 100$ for mains and a rod kit is a lot cheaper than 250 for them plus a piston kit and a bore job after she pops her cookies. oh yeah, and word of advice...unless its a race motor, it isnt designed to be run WOT for more than 10 seconds at a time. and if you feel the motor getiing hotter and hotter, stop and let it cool down. crazy bastardo!

Thanks for the advice. I will start tearing top end off tomorrow and check it out. Just sounds rattly when running.

[Erics350x]

could be the rist pin bearing.

[slothminx]

If your R didnt have enough power to pull 2nd or third, maybe even 4th in it you already had a problem. 2nd gear with a 6 speed close ratio box is barely higher then 1st, a properly running R would tear up that dirt.

[crackshot]

could be the rist pin bearing.

Thats what it sounds like to me too.

[crackshot]

Well If I am going to tear into this, I might as well rebuild bottom end and have new crank bearings, seals and counter balancer bearings installed.
Anyone know any shops that rebuild bottom ends that I can send this out?

[crackshot]

Ok. Tore top end down and piston was clanking around inside bore.
Bottom end is fine thank goodness. Rod has spec side to side play and turns freely.
Piston is cracked in 2 places and rings still in tact. Caught it just in time.
It's like the bore is wore out.
I will take cylinder in tomorrow to get checked and see if I need bore or hone and oversize piston.
Thanks for all the help.

[crackshot]

Ok heres the verdict.
Piston was 66 and bore was oversize. Dude I bought it from must have mis judged piston size big time.
When I pulled cylinder off, the rings jumped out of grooves and crossed each other.
Half the top ring was in bottom groove and vice versa. That is where I got clanking noise.
I saved myself a costly repair on bottom end because rings and piston were still in tact although piston has 4 cracks in it from the slap.
So I took it down to Starting Line Products machine shop and having the works done to it and having the piston fitted to bore.
Got my power reeds in and after bore and port, it will be ready to rip in about a week.
Too bad I am not going to trike fest. I would have to spank all of you and take all the prizes home.

[slothminx]

Ok heres the verdict.
Piston was 66 and bore was oversize. Dude I bought it from must have mis judged piston size big time.
When I pulled cylinder off, the rings jumped out of grooves and crossed each other.
Half the top ring was in bottom groove and vice versa. That is where I got clanking noise.
I saved myself a costly repair on bottom end because rings and piston were still in tact although piston has 4 cracks in it from the slap.
So I took it down to Starting Line Products machine shop and having the works done to it and having the piston fitted to bore.
Got my power reeds in and after bore and port, it will be ready to rip in about a week.
Too bad I am not going to trike fest. I would have to spank all of you and take all the prizes home.

Not a chance they could do that in the cylinder, I got a piston and rings in front of me here and you would have to have the cylinder 5mm too big to have that happen.