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B+ exhaust advice

Posted: Mon Apr 17, 2017 12:55 pm
by relic
I've suspected that my exhaust is a little louder than it should be. I first removed the end spark arrestor (#64 on the schematic) and wrapped it in packing which helped a lot. I was reluctant to remove the entire baffle (#63 on the schematic) because one of the welded nuts had broken loose and so the bolt was turning freely. Tonight I've carved the head off the bolt with my die grinder and you can see what I've found---nothing. At some point I guess someone seeking more HP thought it best to remove the baffle entirely.
So my questions are --- should I bother trying to fix this? Will the missing baffle affect performance adversely?
Would a baffle tone down the volume significantly?

Thank you once again for any advice.

Image

Ken

Re: B+ exhaust advice

Posted: Mon Apr 17, 2017 1:11 pm
by matt glascock
Ummm. I don't think that will pass tech. I found the exact same thing on a M94 Wombat. I purchased and installed a replacement but didn't experience any performance enhancements other than (possibly) a teensy tiny bit more low-end pull. Interestingly, someone did the same chop job to my M95 Combat Wombat. That situation called for the entire flame thrower removal and installation of an FMF Turbinecore II. Now that made a difference everywhere on the rev range.

Re: B+ exhaust advice

Posted: Mon Apr 17, 2017 1:44 pm
by relic
Thanks Matt. This is just a rider, will be plated and insured but will be no issue with that here. I can live with the extra noise for now as long as I know it won't affect anything else. Budget wise, if I can put off purchasing a new one for a while that would be good.
Ken

Re: B+ exhaust advice

Posted: Mon Apr 17, 2017 3:41 pm
by viclioce
If you weld, you might try tack welding some steel strips to it and wrapping with some wood stove door gasket. I did that with a different bike to generate needed back pressure & the door gasket can just be wound around and will help quiet things down too while providing some needed back pressure. :mrgreen: Victor

Re: B+ exhaust advice

Posted: Mon Apr 17, 2017 5:15 pm
by matt glascock
Good call, Ken. They are a bit spendy to replace. I didn't notice any significant difference on the top end and that's what you are likely interested in for road work anyway. The pipe might not scavenge as well which may lead to a lean condition. You might consider jetting to rich then dialing it back a size.

Re: B+ exhaust advice

Posted: Mon Apr 17, 2017 8:11 pm
by Bullfrog
What Matt said. (and I've urged quietness for motorcycles since 1971 . . . as soon as you can quiet it down, I hope you will)
Ed
PS: Even my "go fast" bike has a full spark arrestor/silencer. Noise is not your friend.

Re: B+ exhaust advice

Posted: Tue Apr 18, 2017 12:30 am
by relic
Total agreement on the noise issue, Ed and Matt! So far I've only been annoying a few of my neighbors as I live on a fairly rural road. :) I wasn't sure how much difference the missing part would make in the sound?
Yes, I see the arrestor/silencer is a bit spendy and with me being up here in the great white north, (my problem I know) it makes it much worse.
I've made baffles before when I've got something left of an old one to copy but in this case its all gone.

thanks for the info
Ken

Re: B+ exhaust advice

Posted: Tue Apr 18, 2017 7:39 am
by bobwhitman
... and without the missing part, the bike doesn't meet USFS requirements and events like the Bad Rock trail ride.
Bob

Re: B+ exhaust advice

Posted: Tue Apr 18, 2017 1:59 pm
by relic
Yes Bob, another thing to consider. Hodaka Days is number one on my bucket list of lifetime adventures. Its 2700 miles from me. So I'll need more than the one week holidays I get now.
For certain I'll do something, just not sure which way I'll go at this point. I dug out a couple of silencer/baffle assemblies from other bikes in my parts stash so possibly I can modify something to work. I have the inner pipe, #3 on the page of the manual you can see in my first post photo. I'll play around a bit and see what I come up with first.
If not I'll buy the part.
thanks everyone.
Ken