Signs of overheating?

[dropitlow88]

Took the bike out to the store this evening and started having some strange issues... Ran it pretty hard there and back, and on the way back it seemed like it was running out of gas  ... switched to reserve, onward down the dirt road i live on. It was idling erratically, sometimes on one cylinder. pull into my shop and left it running, it seemed to be idling perfect again. Twist the throttle a few times, erratic idle with some backfiring through the exhaust. I also have a breather filter, not the hose into the airbox and i could see puffs of smoke coming out of it (blow by) in relation to throttle. It does not do this when cold. i assume it to be normal considering it is an air cooled engine with high tolerances. So anyway, i shut it off and i can hear what sounds like oil burning in the head, like a grease spattering noise, (not normal ) My only other guess would be that it is time for a valve clearance job... The tight clearances causing some exhaust gas to escape past the valve overheating the valve and the head.. (hope not) Thanks guys.

[Kijona]

Took the bike out to the store this evening and started having some strange issues... Ran it pretty hard there and back, and on the way back it seemed like it was running out of gas  ... switched to reserve, onward down the dirt road i live on. It was idling erratically, sometimes on one cylinder. pull into my shop and left it running, it seemed to be idling perfect again. Twist the throttle a few times, erratic idle with some backfiring through the exhaust. I also have a breather filter, not the hose into the airbox and i could see puffs of smoke coming out of it (blow by) in relation to throttle. It does not do this when cold. i assume it to be normal considering it is an air cooled engine with high tolerances. So anyway, i shut it off and i can hear what sounds like oil burning in the head, like a grease spattering noise, (not normal ) My only other guess would be that it is time for a valve clearance job... The tight clearances causing some exhaust gas to escape past the valve overheating the valve and the head.. (hope not) Thanks guys.

Remove the bacon from the valve cover. In the future, please keep in mind that bacon can cause premature gasket failure as well as wrong jetting.

In all seriousness, yes...overheating. Why? Check for signs of exhaust leak...also, does it backfire a lot? Might need to change your oil...put something heavier in it like 20w-50. Extremely tight valves can cause overheating as well.

[dropitlow88]

Took the bike out to the store this evening and started having some strange issues... Ran it pretty hard there and back, and on the way back it seemed like it was running out of gas  ... switched to reserve, onward down the dirt road i live on. It was idling erratically, sometimes on one cylinder. pull into my shop and left it running, it seemed to be idling perfect again. Twist the throttle a few times, erratic idle with some backfiring through the exhaust. I also have a breather filter, not the hose into the airbox and i could see puffs of smoke coming out of it (blow by) in relation to throttle. It does not do this when cold. i assume it to be normal considering it is an air cooled engine with high tolerances. So anyway, i shut it off and i can hear what sounds like oil burning in the head, like a grease spattering noise, (not normal ) My only other guess would be that it is time for a valve clearance job... The tight clearances causing some exhaust gas to escape past the valve overheating the valve and the head.. (hope not) Thanks guys.

Remove the bacon from the valve cover. In the future, please keep in mind that bacon can cause premature gasket failure as well as wrong jetting.

In all seriousness, yes...overheating. Why? Check for signs of exhaust leak...also, does it backfire a lot? Might need to change your oil...put something heavier in it like 20w-50. Extremely tight valves can cause overheating as well.

awww damn, love the fresh smell of bacon on the way to work in the am...  gonna reall screw up my bacon egg chz sandwich when i get to work...lol
It just started doing this and i have not checked the valves yet, i guess it's that time. ugh.. It just started the backfiring, just at low rpms and steady throttle state however, not on decel. Could have gotten more crud in the carbs from my POS gas tank lol. Guess i'll dive into it head first tomorrow (with my helmet on of course, safety first  )

[Kijona]

Took the bike out to the store this evening and started having some strange issues... Ran it pretty hard there and back, and on the way back it seemed like it was running out of gas  ... switched to reserve, onward down the dirt road i live on. It was idling erratically, sometimes on one cylinder. pull into my shop and left it running, it seemed to be idling perfect again. Twist the throttle a few times, erratic idle with some backfiring through the exhaust. I also have a breather filter, not the hose into the airbox and i could see puffs of smoke coming out of it (blow by) in relation to throttle. It does not do this when cold. i assume it to be normal considering it is an air cooled engine with high tolerances. So anyway, i shut it off and i can hear what sounds like oil burning in the head, like a grease spattering noise, (not normal ) My only other guess would be that it is time for a valve clearance job... The tight clearances causing some exhaust gas to escape past the valve overheating the valve and the head.. (hope not) Thanks guys.

Remove the bacon from the valve cover. In the future, please keep in mind that bacon can cause premature gasket failure as well as wrong jetting.

In all seriousness, yes...overheating. Why? Check for signs of exhaust leak...also, does it backfire a lot? Might need to change your oil...put something heavier in it like 20w-50. Extremely tight valves can cause overheating as well.

awww damn, love the fresh smell of bacon on the way to work in the am...  gonna reall screw up my bacon egg chz sandwich when i get to work...lol
It just started doing this and i have not checked the valves yet, i guess it's that time. ugh.. It just started the backfiring, just at low rpms and steady throttle state however, not on decel. Could have gotten more crud in the carbs from my POS gas tank lol. Guess i'll dive into it head first tomorrow (with my helmet on of course, safety first  )

Backfiring during steady throttle? Almost surely an exhaust leak near the headers. This would absolutely cause an overheat. Check the exhaust gaskets. Also, check to make sure there are no cracks in the welds on the pipes or it's not rusted through anywhere.

Addendum: Backfiring could also be caused by really tight valves. I'd check the easier of the two first, though, which is the exhaust. Put your hand (with a rag) over the end of the exhaust and see if it stalls. This will also allow you to hear any sounds of air escaping near the header.

[dropitlow88]

one of the first things i checked. That's why it seems so strange, it's so random, just outta nowhere. everything looks great, no leaks, rust, etc.

[Kijona]

one of the first things i checked. That's why it seems so strange, it's so random, just outta nowhere. everything looks great, no leaks, rust, etc.

Did you remove the header screws? The gaskets could've disintegrated.

[dropitlow88]

they are new from when i built the engine and still tight. i'm starting to lean toward valve clearances in after thought. it's the only thing i have not done yet.

[Kijona]

they are new from when i built the engine and still tight. i'm starting to lean toward valve clearances in after thought. it's the only thing i have not done yet.

Oh...well then yea, I'd definitely check the valves.

After that...timing being off could screw it up too.

[mister]

Heavier oil? WTF for?

@Dropit before you go starting ripping everything apart cause Kijona said, stop for a moment, ok.

Chances are you may or may not have done a gasket. Specially if you were going hard. Specially if you filled the oil right up to the top of the F. The only thing heavier oil will then achieve is to create greater pressures and make such a problem worse.

If checking your valves will make you happy, then check them. Make whatever corrections you need to make then report back.

But you could have fuel issues, spark issues, issues with the wrong alignment of the planets, all kinds of things. So start simple to make sure you are not chasing your tail and to help diagnose other potential issues. Simple like, pulling your spark plugs and seeing what they tell you. Pull, take snap, load pic up for use to see and comment on. Then go from there.

Michael

[dropitlow88]

alright, so i took it out this morning on a longer run. turns out it is starving itself of fuel, with the petcock in ANY position. Riding at 60-70mph, one cylinder will get weak, then drop out, then shortly thereafter the other side will drop out. pull off the road, wait two minutes and the cycle repeats again. going to check for kinks in the line, and or trash in the carbs needle and seat impeding fuel flow. The exhaust backfiring was from going lean.

[oz353]

search the forum for tank vent cleaning. that sounds almost exactly the type of problem related to clogged tank lid vent.

[dropitlow88]

i don't have the stock cap. it's a brand new aftermarket unit. The problem was within the right side carb. i recently replaced the needle/seat o-rings with some i had laying around. they were slightly larger than the old ones. it worked its way back out of the bore somehow but still sealed?? anyway, it caused the float level to be super low. Hence the starving. replaced o-ring and now all is well, running great again.

[ohgood]

i don't have the stock cap. it's a brand new aftermarket unit. The problem was within the right side carb. i recently replaced the needle/seat o-rings with some i had laying around. they were slightly larger than the old ones. it worked its way back out of the bore somehow but still sealed?? anyway, it caused the float level to be super low. Hence the starving. replaced o-ring and now all is well, running great again.

see, if you'd just run Full Synthetic REDLINE oil and OEM filters instead of the cheap crap - this kind of thing would never happen.


















and -that- was just a dig at the oil nazis. enjoy your bike 

[Kijona]

Heavier oil? WTF for?

@Dropit before you go starting ripping everything apart cause Kijona said, stop for a moment, ok.

Chances are you may or may not have done a gasket. Specially if you were going hard. Specially if you filled the oil right up to the top of the F. The only thing heavier oil will then achieve is to create greater pressures and make such a problem worse.

If checking your valves will make you happy, then check them. Make whatever corrections you need to make then report back.

But you could have fuel issues, spark issues, issues with the wrong alignment of the planets, all kinds of things. So start simple to make sure you are not chasing your tail and to help diagnose other potential issues. Simple like, pulling your spark plugs and seeing what they tell you. Pull, take snap, load pic up for use to see and comment on. Then go from there.

Michael

If it's really hot the heavier oil will be more suitable. If the oil is getting too thin it could be causing excess friction. I had that issue on my KLR. It absolutely ran cooler with 20w-50 versus 10w-40.

Another thing to consider is that the fuel starvation could be caused by the overheating. Also had this issue on my KLR - it would get really hot and then the fuel would start boiling as it hit the carburetor. No doubt about it since it had clear fuel lines and you could see it boiling as it entered. It also made a sound as it boiled that sounded a LOT like what OP was describing - sizzling grease.

And Mister, I was just trying to help the guy out. Hell the title of the thread asks what could cause overheating. I was answering the question. FYI he was leaning towards checking the valves before I said anything anyway.

[dropitlow88]

for what its worth i run 10w-40 castrol gtx semi-syn. and oem filter. Rode all day today after fixing the carbs in it ran perfect. flogged it. no issues.