immediidingate Overheating/popping

[rigsby]

Hello Everyone...I am new here & from Oregon. It is nice to meet you & share our love for the XR & riding.

I recently got a 96XR400 out of retirement for about 2 years. It has been started occsionally... my friend had ridden it 4 or 5 times since i owned it before. It is in excellent shape... still has the original "XR400" logo not worn from the seat. This bike has lows hours/miles.

It starts great, head/piston nice & quitet, geat compression. Air cleaner is new (UNI), new oil, new fuel (92/100 octane mix), fuel/air screw is adjusted, etc....

Within 1 to 2 minutes, it overheats so bad that the exhaust pipe glows Orange!!! it pops on decelleration, lacks a little power. I shut it off & have & have not ridden it due to above problem. I think it may be a valve issue??? but no noise... seems tight. Ideas?? Thanks!!

[AlanH]

Maybe gummed up carb jets from where it was standing causing it to run horribly weak.

[jasonbc]

Hello Everyone...I am new here & from Oregon. It is nice to meet you & share our love for the XR & riding.

I recently got a 96XR400 out of retirement for about 2 years. It has been started occsionally... my friend had ridden it 4 or 5 times since i owned it before. It is in excellent shape... still has the original "XR400" logo not worn from the seat. This bike has lows hours/miles.

It starts great, head/piston nice & quitet, geat compression. Air cleaner is new (UNI), new oil, new fuel (92/100 octane mix), fuel/air screw is adjusted, etc....

Within 1 to 2 minutes, it overheats so bad that the exhaust pipe glows Orange!!! it pops on decelleration, lacks a little power. I shut it off & have & have not ridden it due to above problem. I think it may be a valve issue??? but no noise... seems tight. Ideas?? Thanks!!

On those symtoms it seems it's running far to lean, don't know what your octane grades are in the states but 95ron runs perfect over hear try richening it up and run it on your 100 ron or equivelant and see what happens

[rigsby]

On those symtoms it seems it's running far to lean, don't know what your octane grades are in the states but 95ron runs perfect over hear try richening it up and run it on your 100 ron or equivelant and see what happens

Thanks everyone for listening to my dillema. I think the octane is fine... as i have mixed 92 & 100 (50/50 mix). being that I have ran this bike on less octane, I am lead to believe that I must adjust the valves?? I have never adjusted them before. One of the header pipes glows!! I am concerned about the valve lash... but not sure.

[mad4it028]

its running lean!

[AlanH]

I am lead to believe that I must adjust the valves?? I have never adjusted them before.

From my experience with bikes that have been laid up for a while - especially those that are started occasionally, people don't tend to carefully drain the carb before leaving the bike to stand in storage. The fuel in the carb evaporates and leaves a gummy deposit in the jets. This restricts the flow of fuel through the jets so it makes the bike run lean and can really mess with the pilot circuit.

Who has led you to believe it's valves? By all means check the valve clearances but tight valves won't give these symptoms and loose valves will rattle.

[walesxr]

If you decide to check the valve clearances, just be aware that the right hand exhaust has a auto de-compressor, so do make sure that you follow the instructions in your manual when getting engine crank into correct position. Otherwise you will think that you have a tight tappet.

[catteeclan]

I think the octane is fine... as i have mixed 92 & 100 (50/50 mix). being that I have ran this bike on less octane, One of the header pipes glows!!

Def running lean.