bike overheating help!!!!

[Ryan12833]

I have a 1987 honda xl250 that is overheating, please help if you can. It started yesterday when i had a plug in the bike meant for 5 degree weather or below. I checked it this morning, this is what i did:

alright, it runs fine, idles good, sometimes it dies.

Here is what i did this morning.

I put a new plug in, the one with the correct heat index.
I cleaned the fuel filter, although it was not dirty at all, not even a spec of dirt.

I know the carbs are getting fuel.

I had the bike running at 1 3/4 turns out on the air screw and to about 2 1/2 turns out. It doesnt affect the bike too much at all. it started pretty quick, so i ran it are my negiborhood (1/2 mile) in third gear and forth. When i got back it started to smoke white smoke a little but not alot at all. Then it died. I got it started again but i didnt want to ride it.

I pulled the plug and it seemed like it was still overheating. Im not sure what the problem is. The plug after i ran it was starting to get white again. Thanks for any help. Im trying to ride with my freind monday and its not looking good.

 

[Ryan12833]

alright, i got the bike to run really well. It doesnt die any more. I just had to turn the idle up a bit.

I ran the bike about 1 mile with the airscrew about 7/8 of a turn out. The manual said to turn it in if it is running lean. So i went from 1 1/2 (factory reccommended starting point) to 1 turn out and it was running a bit lean. So i went to 7/8 of a turn out and i think i should try 3/4 turns out.

My question is, is it safe to do this? It seems like only a 3/4 turn out is not enough. Will it hurt the engine? thanks for any help. Other than that it is running really well.

 

[apb]

I'm not positive, but on thumpers, the pilot screw is usually a fuel screw rather than an airscrew like your kdx has. So turning the fuel screw in should further lean the mixture for the pilot circuit, rather than making it more rich like you described. Maybe some of the xr/xl guys can confirm this. I know your bike also has the old twin carb design as well, which could make the carb adjustments a little more difficult to dial in. Good luck with it.

 

[Ryan12833]

alright, i got it too run really well, the air screw is only out 3/4 of a turn or a bit less. Is this ok? Factory specs say to start at 1 1/2 turns out. I did but it was too lean. Will i hurt my motor by running it only 3/4 of a turn out?? thanks for any help.

 

[Clark Jeff]

If your bike is overheating, it's important to address the issue promptly to prevent potential damage to the engine. Here are some steps to help you diagnose and resolve the problem:

1. Stop Riding: If you notice that your bike is overheating, pull over immediately and turn off the engine. Continuing to ride while the engine is overheating can lead to severe damage.
2. Check Coolant Level: Check the coolant level in the radiator. Low coolant levels can lead to overheating. If it's low, top it up with the recommended coolant mixture.
3. Inspect for Leaks: Look for signs of coolant leaks around the radiator, hoses, water pump, and other cooling system components. Even small leaks can lead to overheating.
4. Radiator Blockage: Examine the radiator for obstructions like dirt, mud, or debris. Clean the radiator if it's clogged to allow for proper airflow.
5. Coolant Mixture: Ensure that the coolant mixture is correct. It should be a 50/50 mix of coolant and distilled water. Using the wrong ratio can affect cooling efficiency.
6. Check Hoses: Inspect the coolant hoses for cracks or damage. Replace any damaged hoses as needed.
7. Thermostat: Test the thermostat to see if it's stuck closed, which can impede coolant flow. If it's not functioning correctly, replace it.
8. Water Pump: Ensure that the water pump is functioning correctly and circulating coolant through the system. If it's not, it may need to be replaced.
9. Fan Operation: If your bike has an electric cooling fan, check if it's working properly. The fan should kick in when the engine temperature rises. If it doesn't, investigate the fan and its associated components.
10. Riding Style: Avoid prolonged idling or slow-speed riding, as this can contribute to overheating. Keep the bike moving to maintain airflow over the radiator.
11. Check Engine Oil: Low engine oil levels or using the wrong type of oil can also contribute to overheating. Ensure the oil level is correct and use the recommended oil grade.
12. Inspect the Cooling System: Examine the entire cooling system for any visible damage, loose connections, or worn components. Address any issues you find.

If you've checked these aspects and the overheating issue persists, it's advisable to have your bike inspected by a qualified mechanic or a dealership. They can perform a more thorough diagnosis, including pressure testing the cooling system and assessing the condition of internal engine components. Overheating problems can sometimes be caused by more complex issues that require professional attention.