running hot... overheating 2 stroke

Status
Not open for further replies.
Caster is great stuff. I run a little of that in my model airplane engines also. Haven't used any of it in my motorcycles though.
 
Overheating 2 stroke

i dont know why but my Chinese 2 stroke motor as been overheating.I dont know why? After about 15 minuts of running, i feel the motor and its very hot. This cant be normal because when it s overheated the motor dies after i turn it on. Can anyone help?
 
overheating

Is this an engine you have had for a while and just now started running hotter? or is this a new engine thats been running hot right out of the box?
Perhaps its putting out a normal amount of heat as all these engines will get too hot to touch for more than a second or 2.
Make sure you have the right oil/fuel mixture too,16/1 is good for new motors.MAC
 
first thing to do is check the sparkplug colour... if its a pale grey/white then its a mixture problem.. since it happens after 15 minutes of riding its likely that its a weak mixture at the higher end of the rev band.

is it the cylinder thats getting hot or is it any other part of the engine/clutch combo.. because that could be a symptom of friction somewhere in the system due to lack of lubrication..

As has been said, its worth checking the mixture as well - you may be running too low an oil mixture and that would cause friction based overheating and alot of engine wear as well..

hope that helped

Jemma xx
 
okay, ill first make my self clear. the bike and motor turn on with ease. after about 15 minutues, the cylinder gets very hot. i cant touch it for more then 1 sec. everything elese is perfect. i have had the motor now for 2 months and this is the first time it has happened.
1. can someone tell me what the oil mix is supposed to be?
2.how to you check the sprak plug colour?
3.can be be any other problem after i have told you this information.

p.s
to clear thing up, if your engine is running hot, do you increse of decrese the oil.

thanks
 
24:1 is a safe fuel/oil ratio, I use 32:1 with no ill effects. (less oil spooge out the exhaust too)

If your engine is overheating, it is probably because of an overly lean mixture. If you do a lot of riding at WOT and high RPM's, the mixture could be leaning out. My bike has a pronounced "lean bog" when it approaches top speed, where the engine runs stronger at 3/4 throttle than it does at full throttle. I noticed this as the weather got colder (40's). It ran fine when the temps were in the 80's - but since cool air is more dense, more fuel is needed to keep the proper A/F ratio. The mixture seems rich enough at lower speeds, so for now, I keep my speeds around 20. The "proper" way would be to re-jet the carburetor with a larger main jet. The stock carbs have a mixture needle that you can raise or lower, and this will adjust idle/mid range mixture - but maximum flow is regulated by the main jet.

During normal operation, the cooling head and fins on the barrel are too hot to touch. An overheating engine should burn flesh almost instantly.
 
overheating

24:1 is a safe fuel/oil ratio, I use 32:1 with no ill effects. (less oil spooge out the exhaust too)

If your engine is overheating, it is probably because of an overly lean mixture. If you do a lot of riding at WOT and high RPM's, the mixture could be leaning out. My bike has a pronounced "lean bog" when it approaches top speed, where the engine runs stronger at 3/4 throttle than it does at full throttle. I noticed this as the weather got colder (40's). It ran fine when the temps were in the 80's - but since cool air is more dense, more fuel is needed to keep the proper A/F ratio. The mixture seems rich enough at lower speeds, so for now, I keep my speeds around 20. The "proper" way would be to re-jet the carburetor with a larger main jet. The stock carbs have a mixture needle that you can raise or lower, and this will adjust idle/mid range mixture - but maximum flow is regulated by the main jet.

During normal operation, the cooling head and fins on the barrel are too hot to touch. An overheating engine should burn flesh almost instantly.
Hi.
Having just bought a second hand bike with a 80cc engine I tried it out today.after getting the engine started it seemed to be coughing and spluttering alot during the revs I cant get full throttle as it seems like it will cut out.
and on feeling the motor it seemed hot to touch.I put a ratio of around 25/1. the seller told me he had ridden it for about 20 miles overall .
I do have an E Bike but I'm new to these motorized 80cc bikes any help would be appreciated.
I just hope I haven't been sold a dud bike which has been hammered.
I'm from the UK
 
Hi.
Having just bought a second hand bike with a 80cc engine I tried it out today.after getting the engine started it seemed to be coughing and spluttering alot during the revs I cant get full throttle as it seems like it will cut out.
and on feeling the motor it seemed hot to touch.I put a ratio of around 25/1. the seller told me he had ridden it for about 20 miles overall .
I do have an E Bike but I'm new to these motorized 80cc bikes any help would be appreciated.
I just hope I haven't been sold a dud bike which has been hammered.
I'm from the UK
 
Is there oil on top of the cylinder close to the gasket? If so then your have an air leak at the head/cylinder juncture which causes it to run hotter.
Use sandpaper on glass to resurface the head to be truly plane. And make your own gasket from gasket material which will seal way better than them cheap shetty aluminum gaskets.
 
Status
Not open for further replies.
Back
Top