Bike Is Overheating

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May 30, 2007
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#1
I was riding out on the track that my friend and I have for about 6 hours in 90+ degree weather (very hot for Wisconsin). The bike was just re-jetted and I put a new plug in. Anyways, we were riding for quite some time, and went back to get some more to drink and we decided to take an access road back instead of a path we made. I started to pull into his drive way and down shifted from 5th to 1st and let the clutch out in 1st and it bogged down and died on me. I tried kicking it and it wouldn't start. I was thinking it was just a fouled plug so I took the plug out and checked for spark and that was perfect. We waited about 30 minutes and came back out and it started right up with normal power. I was a little worried so I just kept it in neutral giving it a little gas for 2 minutes and then it started to bog down again and died.

As of right now, I was thinking it could maybe be a busted Impeller in the water pump because rubber hardens over the years. So I was just wondering if any of you knew what is really wrong with the bike. Thanks for any help.


**PS. If it makes any difference, I just bought a new pipe and silencer, I don't think it'd do anything, but it was the first ride on them. Thanks again.
 

dirt bike dave

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#3
If you we running it hard on the road after a long hard riding session, it is safe to assume the motor was very hot.

If you downshifted through the gears (using the engine to brake) with the throttle off, you deprived the motor of cooling fuel and lubricating oil at a time when it needed it most, as your motor was very hot and revving high.

The lack of fuel and oil in a hot two stroke engine can cause all kinds of problems. I think it is going to be something other than your water pump impeller. I would pull the cylinder and inspect it as well as the piston. Also inspect the rod and crankshaft for freeplay in the bottom end.

FWIW, last time I de-celled a hot two stroke after a sustained wide-open top gear run on the road, I had to replace the crankshaft assembly, a center case, piston, both crankshaft bearings, etc.... Luckily my cylinder was undamaged.

I'll guess if you had just cruised slowly on the road and coasted to a stop with the clutch in, your bike would be fine. They really really don't like no fuel and oil when they are red hot.
 
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#4
Well I wasn't engine braking totally, I was also using front brake and didn't engine brake hard. So I should pull apart the cylinder and check out the piston for scoring? If so, my uncle owns a cylinder service shop (Millennium Technologies if anyone has heard of it) and they get pistons 60% off so that wouldn't be a problem to get a new one.

Edit: Like I said, I checked the plug and it was still a little on the richer side, so jetting isn't the problem.
 
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#5
You don't need to pull a cylinder apart to check the condition of the piston or cylinder. You can inspect through the exhaust and intake ports. Just pull the reeds and pipe.
 
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#6
76GMC1500 said:
You don't need to pull a cylinder apart to check the condition of the piston or cylinder. You can inspect through the exhaust and intake ports. Just pull the reeds and pipe.
True, but you cant get a good look at the whole cylinder this way.
 
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#7
j.lawson said:
True, but you cant get a good look at the whole cylinder this way.
if you scored your cylinder there would be marks on the piston. looking through the intake and exhaust ports will give you access to viewing almost 2/3rds of the cylinder and piston.
 
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#10
wait, after re-reading your first post, Why are you looking in your cylinder yet? Go buy a new plug and try that. Check the most simple things first. If it died, then restarted and idled fine, then died it could be a number of simple things, somthing in your carb (float?), gas cap vent, fouled plug, air leak, ect, ect.... before you go tearing your bike apart check the little things. :cool:
 
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#11
It costs $11 for a new plug if you've got an iridium and you have to make a trip to the store. Pulling the pipe costs nothing, takes about 30 minutes to do, and can really tell you a lot about your engine. It's actually faster and cheaper to pull the pipe than it is to buy a new plug.
 
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#13
It didn't idle fine, my bike never does actually and I said the spark had awesome spark yet so it can't be a fouled plug can it?
 
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#14
thecount said:
try using engine ice

engine ice is just a marketing scam. all coolant works the same, you cant get some magical stuff that colls your bike more than others.
 
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#15
MXer666 said:
engine ice is just a marketing scam. all coolant works the same, you cant get some magical stuff that colls your bike more than others.
You're wrong.