F800GS Excessive heat from exhaust

[Ratchdaddy]

I have been noticing on the last few rides that my exhaust seems much hotter near my left heel. If I am riding with the balls of my feet on the pegs and my heels up by the heel protector it is actually too hot to keep my heels there for extended periods.

I know for a fact that it was not that hot before. I replaced the stocker heel protector with the touratech metal one but I have had it on there for quite awhile so that is not the issue.

The engine temp indicator has never gone above the normal reading even during extended slow speed off road. When it is in the 30-40 degree range outside it reads one bar below normal.

Anyone else have this issue? I am wondering if maybe my catalytic converter is shot or something. The bike has 33,000 miles and I have noticed a fuel mileage drop but I thought that was from winter fuel mix in California.

[ebrabaek]

Originally Posted by Ratchdaddy

I have been noticing on the last few rides that my exhaust seems much hotter near my left heel. If I am riding with the balls of my feet on the pegs and my heels up by the heel protector it is actually too hot to keep my heels there for extended periods.

I know for a fact that it was not that hot before. I replaced the stocker heel protector with the touratech metal one but I have had it on there for quite awhile so that is not the issue.

The engine temp indicator has never gone above the normal reading even during extended slow speed off road. When it is in the 30-40 degree range outside it reads one bar below normal.

Anyone else have this issue? I am wondering if maybe my catalytic converter is shot or something. The bike has 33,000 miles and I have noticed a fuel mileage drop but I thought that was from winter fuel mix in California.

You might be on to something. If your CAT is plugged somewhat it will burn more gas, and get hotter down stream. Why would it be plugged..... I have no clue. But when you see more than one variable change, then it is good of you to observe. One cheap remedy you can try, is a boad load of Techron.... Just to make sure your injectors are functioning fine.

[Ratchdaddy]

Originally Posted by ebrabaek

You might be on to something. If your CAT is plugged somewhat it will burn more gas, and get hotter down stream. Why would it be plugged..... I have no clue. But when you see more than one variable change, then it is good of you to observe. One cheap remedy you can try, is a boad load of Techron.... Just to make sure your injectors are functioning fine.

I will try some injector cleaner, I ride daily so I don't worry about bad gas and I usually use either Chevron or Shell gas. I am going to ride the 80 miles down to Riverside on my day off to see what the dealer says I guess.

[4TooMany]

Originally Posted by ebrabaek

You might be on to something. If your CAT is plugged somewhat it will burn more gas, and get hotter down stream.

I've gotta disagree. If the exhaust was plugged, it would run richer, yes, but it would also run cooler.* Also, if it was clogged enough to make any difference in temperature, you'd have a noticeable loss of power. At risk of sounding like an ass, I think it's all in your head. The bike, stock, already runs so lean (and hot) that if it were running lean enough for the exhaust to get hotter, it wouldn't run at all. Just my two pennies.

*Edited to add: the only way in which excess fuel would cause the cat to get hotter is if there was also excess oxygen. The only way that would happen is if the bike was misfiring. And if it was misfiring, you'd notice. Simply running rich due to being clogged would make it run cooler.

[ebrabaek]

Originally Posted by 4TooMany

I've gotta disagree. If the exhaust was plugged, it would run richer, yes, but it would also run cooler.* Also, if it was clogged enough to make any difference in temperature, you'd have a noticeable loss of power. At risk of sounding like an ass, I think it's all in your head. The bike, stock, already runs so lean (and hot) that if it were running lean enough for the exhaust to get hotter, it wouldn't run at all. Just my two pennies.

*Edited to add: the only way in which excess fuel would cause the cat to get hotter is if there was also excess oxygen. The only way that would happen is if the bike was misfiring. And if it was misfiring, you'd notice. Simply running rich due to being clogged would make it run cooler.

I agree on the rich running. I was thinking that if it has been running rich for a while ( op reporting poor gas mileage) sod can build up on hot spots.... The cat is one big hot spot. If it gets enough gunk in there the cat looses it's efficiency. It can of course be anything.

[ride2little]

I had ruined a new pair of boots on the shifter side of the bike. After running in the mountains all week, I had apparently snapped off the heel guard, unnoticed. That-is until half way through Kansas in 105 temps. I smelled burning rubber at a rest stop. I THOUGHT my heel felt warm. Just thought is was because of the extreme heat. New heel guard, all is well again (except for a melted boot).

As for you just noticing more heat, I'm not sure. A more lean condition would produce more heat for sure. Could be injectors clogging. Could be winter fuels. And yes, I believe a faulty O2 sensor or cat could cause excessive heat.

[Ratchdaddy]

Originally Posted by 4TooMany

At risk of sounding like an ass, I think it's all in your head. The bike, stock, already runs so lean (and hot) that if it were running lean enough for the exhaust to get hotter, it wouldn't run at all. Just my two pennies..

Hmmmm, Well I didn't notice before that I couldn't keep my left foot in a proper riding position on the footpeg without it cooking my boot and my feet, but then I had only put about 30,000 miles on the bike ( most of them in the 80-120 degrees of the Southern California desert that I live in). I suppose you are right and I am just imagining the melted soles on my boots.

I don't pretend to know why it is so hot but thankyou for some of the helpful ideas. Should I check the valves again? They were good at 28K but maybe it wouldn't hurt.

Spoke to the dealer today and I am going to take it in to them on Friday. I have the feeling they don't believe me either. It should be nice and warm by the time I do 90 miles of super slab to get to them.

[4TooMany]

Originally Posted by Ratchdaddy

I suppose you are right and I am just imagining the melted soles on my boots.

It's easy to verify. When you go to the dealer, take an IR termometer with you (the dealer may have one too). Leave your bike off for a while, then start it up and start up one they have at the dealer and measure the temp difference (after they're both completely warmed up).

[Ratchdaddy]

Originally Posted by 4TooMany

It's easy to verify. When you go to the dealer, take an IR termometer with you (the dealer may have one too). Leave your bike off for a while, then start it up and start up one they have at the dealer and measure the temp difference (after they're both completely warmed up).

I almost bought an IR thermometer today. Instead I went home and tore the bike apart. Spark plugs look good. Both exhaust valves for Cylinder 1 were too tight.

Then I called the dealer. According to the service manager, the valve specs for the F800 are IN .23-33mm and EX .3-.41mm. Of course this differs from from BMW service DVD and my Haynes manual. With the new specs, all of my valves are too tight.

Time to do some math and get new shims.

I came across another potential culprit in the heat issue. So much gunk had built up from chain oil onto my Richochet skid plate that it was gummed up between the catalytic converter and the skid plate. I suppose I could wash my bike more often. Nah.

[itsatdm]

The specs have changed, but my dealer can't tell my why or when that happened. He can't even find a service notice? It had to be recent as my bike has the old specs.

Your plugs are good, no over heating, no engine knock, no fault code? If your catalytic converter is plugged I would expect some effect on the oxygen sender.

Sounds like a faulty chain oiler to me.

[Ratchdaddy]

Got a box full of parts from A & S Cycles out of Sacramento. Ordered all new gaskets and o-rings for the top end as well as the correct shims. Great people to deal with. I just need time to put the bike back together now.