Issue with muffler screws loosening themselves

gary55

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Joined
Nov 27, 2012
Messages
3,945
Thanks for the ideas everyone! After considering your suggestions, I decided to upgrade my exhaust first of all (I’m going to invest in this bike) to a flexible expansion chamber poo-poo exhaust, which will help a bit since there won’t be as much vibration and I can secure it better. The issue with my current exhaust is that since I’m using a large road/mountain bike, the frame itself is really thick and the bracket won’t fit around it. Also, I found some posts on this forum saying that securing the muffler to the bike isn’t really necessary. All in all, I’ve ordered some high quality m6 bolts (I can tighten better without fear of stripping the head, blue medium strength threadlocker, and a flexible expansion chamber poo-poo exhaust with a gasket (stock one is already worn out!).

Aside from the exhaust, I’m planning to paint the engine and exhaust, upgrade to a racing carburetor, install a boost bottle, use a double pull bike lever for brakes, install a gas line and filter that don’t leak fuel like crazy, re-mount the engine with some 1/8 inch rubber, and install a better throttle grip. Lots of stuff in the bag!
Yes to all except these crap items.
PooPoo pipe id exactly that. A piece of sh*t. Poor performance, restricted flow, and possible heat issues for the engine.
Boost bottle is a total hype gimmick that does nothing but shrink your wallet.
Rubber mount won't last. Will allow for more engine vibration. Metal to metal is best with a steel or aluminum piece of tubing used to isolate pinch points from frame at down tube.
If the race carb is the dellorto clone performance increase is hardly if at all noticeable, But they are less prone to leaking due to sticking floats. If it's the CNS it's a total waste of money.
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RB55

Member
Joined
Sep 18, 2019
Messages
42
Yes to all except these crap items.
PooPoo pipe id exactly that. A piece of sh*t. Poor performance, restricted flow, and possible heat issues for the engine.
Boost bottle is a total hype gimmick that does nothing but shrink your wallet.
Rubber mount won't last. Will allow for more engine vibration. Metal to metal is best with a steel or aluminum piece of tubing used to isolate pinch points from frame at down tube.
If the race carb is the dellorto clone performance increase is hardly if at all noticeable, But they are less prone to leaking due to sticking floats. If it's the CNS it's a total waste of money.
View media item 61612
Ok, what exhaust do you recommend? Just the stock? I’m buying the boost bottle since it comes with the racing carburetor and bent intake which I need since the stock one leaks like crazy and the carburetor almost doesn’t fit (I can’t remove it without dismantling the entire engine mount, throttle, clutch, etc.) And for the rubber, I also need it for the gas tank, which doesn’t fit well and keeps slipping off (already had to JB weld a bolt that leaked gas). But I’ve seen several posts on here claiming that rubber dampens the vibrations, which makes sense after all. It’s not too bad on this bike but after about 20mph or so it’s not fun to go faster because of the vibrations, and the bike feels like it’s gonna rattle itself to pieces. Any advice on how to fix this without disassembling my entire engine, drilling holes into the frame, or welding? For the exhaust, I only chose the flex poo poo style since the stock muffler already has a super tight fit and I’m pretty sure that adding a bigger pipe would require me to bend it, which is definitely something I can’t and don’t want to do. Also, the exhaust with the poo poo comes out the back, which would be nice since I kind of get gassed out when the bike’s stopped and the engine is on.
 

gary55

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Joined
Nov 27, 2012
Messages
3,945
If I had to suggest one it would be a mz65, but I don't know how it would fit to your build so I can't say mods wouldn't be needed. Rubber at the tank connection is fine. I use it there all the time. As far as the other mods you are considering I have given you my thoughts on them. These thoughts were developed over 100's of bikes I've built along with 100's of repairs done on other's builds. I believe that some of the other experienced builders on the forum would agree with them, but the one way to learn what works best is through your own experiences. I won't try to discourage you from whatever it is you might think will work. Who knows I'm always open to learning something new.
 

Eddie2Stroke

Member
Joined
Oct 31, 2019
Messages
51
They released a new mz65 pipe, look it up it's called the WC80 pipe. I'm thinking of ordering one instead of welding in a CR80R Exhaust on my 100(80cc) kit. But Other than drilling a hole on the other side of the stock exhaust and using 2002 Toyota Highlander/4Runner 02 sensor gasket. Might also try a 22mm Mikuni carb, when the break in period is done, I also medium blue threadlock'd the bolts.
 

Frogslayer

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Joined
Jan 20, 2019
Messages
789
@RB55 have you jetted your bike? My bike had bad vibes especially at 5k and above until I jetted down. Even the noise coming out of the exhaust is less.
 

RB55

Member
Joined
Sep 18, 2019
Messages
42
@RB55 have you jetted your bike? My bike had bad vibes especially at 5k and above until I jetted down. Even the noise coming out of the exhaust is less.
I’ll probably do it sometime but right now is running great. Max rpm at full throttle with clutch disengaged is about 8,500 and I top out at 35mph and 6,800 rpm. 38T rear sprocket is incredible, can climb really steep hills at 22mph no problem. Keeps RPM low, reducing vibration and making for a much smoother ride. Will also probably preserve engine life. I only weigh 110 but the bike is a super thick and heavy hybrid.
 
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