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Help with funk stuff on my bike

J

jonnywdwd

Member
Joined
Nov 21, 2025
Messages
7
Age
84
Location
Salt Lick City
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There have been a number of mods and hacks on my 2001, some of which I've figured out and some I haven't. I could use some insight on several things.
First, the tank.... why would there be two symmetrical JB Weld repairs on the underside of the tank on each side near the front. Did anything used to be there?

tank_jb.webp
 
There’s nothing in those areas on a standard tank. Can’t think of reason for it to be crash related. Could be close the deepest part of tank where condensation turned to rust I see corrosion starting in other parts of the exterior. Was the bike used for jumps or stunts?

Interesting as Salt Lake City is pretty dry place.
 
There's not much relevant history of this bike which is known to me. I'm glad to hear that there's nothing missing from the tank there.

What brand of shorty slip-on is this?

It's a bit loud for my liking. The PO gave me the stock muffler and am wondering about putting that back on. The bike has a K&N air filter, the main jets are #120, mixture screws are 4.5 turns out and the two rearward holes in the throat of the carbs have been enlarged. What would be the result of restoring the stock muffler with these existing mods?

slip-on_1.webp


slip-on_rash.webp

slip-on_mess.webp
 
Yeah, I'd put the stock muffler on ASAP. I have an Akrapovic slip-on that's just right. Almost as quiet as the stocker.
 
Most of my other bikes have been stock and I've had no desire to change them.
What I understand from reading about slip-ons is that a slip-on alone will negatively affect performance unless re-jetted.
So is the opposite true - if I reinstall the stock muffler on a modded/jetted bike will I be required to return the jets and air filter to stock in order for it to run right?
BTW I'm not interested in maximizing horsepower. It has more than I need. I would just like a quiet bike which is reliable and runs well.
 
jonnywdwd said:
Most of my other bikes have been stock and I've had no desire to change them.
What I understand from reading about slip-ons is that a slip-on alone will negatively affect performance unless re-jetted.
So is the opposite true - if I reinstall the stock muffler on a modded/jetted bike will I be required to return the jets and air filter to stock in order for it to run right?
BTW I'm not interested in maximizing horsepower. It has more than I need. I would just like a quiet bike which is reliable and runs well.
Click to expand...
Switch them and find out ….shouldn’t take more than 30 minutes. You have more faith than me as to previous owner jetting it.
 
The difference between the stock muffler and a slip-on should be minimal. We have had a lot of people do the jet kits with and without a muffler change. No problem either way, assuming the bike was re-jetted properly.
 
Thanks for the responses.
The Roadrunner is history and the stock exhaust is on. It is so much nicer to ride now that the noise pollution is gone.
Blue Flash, I cannot tell any performance difference, which is just fine by me, and the relevant fuel/air mods which I have discovered are listed in post #3.
One thing which does seem to happen with this bike is that the gas disappears faster than my G&Ts.
 
i have those same spots on my fuel tank its where it contacts the frame maybe but vibrations eat through the tank after a while then you get leaks or it may be a clogged tank vent hose dont leave that for too long you might end up vapor locking are you in a hot climate? in the summer i mean
 
supaji said:
i have those same spots on my fuel tank its where it contacts the frame maybe but vibrations eat through the tank after a while then you get leaks or it may be a clogged tank vent hose dont leave that for too long you might end up vapor locking are you in a hot climate? in the summer i mean
Click to expand...
Do either you or the OP have a broken/cracked front mounting clip? I had it happen on one of my tanks. Vibrated wildly after it happened.

Do you have the two rubber baby bumpers on the frame under the tank?

With a good front clip and the two rubber pads it shouldn’t be possible for the tank to contact the frame.


https://www.partshark.com/oemparts/a/yam/50044522f8700209bc78f5cf/fuel-tank

Item 3. and two each Item 41
 
Fuse question. On my bike the main fuse at the starter relay is 25A. The spare fuse is 30A. I checked the specs and Yamaha calls for a 30A fuse here. The bike is running fine with the 25A fuse installed. Is there something I don't know about, whereby the bike's electrical are better off being protected by a 25A fuse, or did the PO just put the wrong fuse in there?
 
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