exhaust pressure

[shierh]

at idle i noticed more exhause comming from the left pipe than the right. Sound is slightly different as well. Is this normal? Factory pipes, 82 gl 1100

 

[Joep]

have you had the carbs synced? .. that could be one reason and cheap to do at that..

 

[joedrum]

these exhaust plug up easy ...especially on the side stand side

 

[dan filipi]

Yes anything that runs this quiet is bound to get clogged up.

 

[shierh]

left side is putting out more exhaust than the right. I rebuilt the right side, had the front baffel out as well as the back baffel and they both flow free. There isnt much in the can part, its more of an expansion chamber. \
Carbs have been syncronized.
Compression is equal 170 all 4.
Just seems odd.

 

[shierh]

by the way on the right head pipe i took die grinder to the weld overflow on each port. Smoothed it way out. Crush seals were missing so put in new ones

I plan to give left pipe same treatment.

 

[joedrum]

the way the exhaust is set up they turn around and actually go right back towards the motor .. there a wall there and the horse turn around is like 3/4" ...ID horseshoe turn

 

[AApple]

Maybe it thinks it's a NASCAR engine in Australia...(think about it...it'll come to ya...) :hihihi:

The baffling/batting may have already blown out of the left side, making it freer flowing?

 

[shierh]

I plan to pull the baffel out of the left. I have to cut off the tail pipe and make it match the pipe on the right side. I made new one with slash cut. Someone tried to revmove the baffels on the right side and hacked up the pipe then covered it up with some tips. I cut off 2inches from the can and got an exact fit pipe from autoparts store and then restored the baffel and welded it all up. came out nice. all painted black.

I did see inside the can at the front part and the front bafel comes into the can and is completely open. No other pipe attached. seems there is some type of diverter at the back of the can but could not see it that well. Could be an issue with the diverter. either way the cross over tube is full size so not going to be much of an issue.

 

[ekvh]

Did you happen to look down into the header pipes? They are prone to expanding in and blocking flow. The pipes are lined and theory is moisture gets in between then suddenly super heated causing them to bulge inward and block flow. There are pics somewhere. I'll look.

 

[mcgovern61]

Wow Eric! I have not seen that before! (That is a great thing about this site...wait for a minute, and you can always learn something new!)

 

[Ansimp]

+1

 

[shierh]

I did look inside and it is good. Fact is that i used a die grinder to grind the upper lip weld smooth.

also someone stated the fiber glass could be out. that has nothing to do with back pressure. the tube is strait through and the glass acts as sound absorber only. if missing it would be louder but same flow. I suspect the left side may have an issue with the rear diverter inside the can. I plan to cut off the tail pipe 1" from the can and replace the tail pipe to match the right side. When I do this the baffel will be pulled and i can then see inside to inspect the diverter. Either way im not cutting it open to fix it, will simply ride as is.

I did however start to ride the bike yesterday and the sound at start up and idle is way different that it use to be now that the right side is rebuilt and the crush gaskets are in place. No more leaky exhaust sound on that side. Put it through the paces with rpms up to 6k and all is well.

Wonder if some of you guys with stock exhaust will start them up and put your hands behind the exhaust and see how balanced they feel, just curious.

 

[mcgovern61]

shierh » Thu Jun 19, 2014 8:50 am[/url]":2m95axfz]
Wonder if some of you guys with stock exhaust will start them up and put your hands behind the exhaust and see how balanced they feel, just curious.

Mine is even on both sides. Do yours feel uneven by the amount of air pushing out before the exhaust gets warm? If so, there must be something blocking it.

 

[dan filipi]

Or a restriction on the carb end?
Sync maybe? Though I don't think a small amount out of sync could be felt at the exhaust.

 

[shierh]

sync is ok, u r right thought it would not make that much difference. Blocking 0n right side has been ruled out. I had whole thing cut apart and rebuilt it properly. I suspect left side is flowing more freely due to some other issue. Possibley the rear diverter is rusted through or someone damaged it by puting a hole in it by driving rod in tail pipe. I will find that out in next few weeks. Got to replace right fork first, leaking oil and ont the brake rotor stopping is not as good as it could. Have spare fork set so just matter of getting around to it.

Unequal exhaust isnt much of an issue though. the cross over tube being full size allows any problems to be diverted to the free flowing side.

 

[mcgovern61]

Out of curiosity, can you check the exhaust temp with a thermal gun at each header pipe to be sure one side is not heating up? Uneven back pressure can play havoc!

 

[shierh]

Dont have one but that is something to consider