Carb rebuild or clean?

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Johnny Glenn

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Joined
Apr 26, 2011
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Location
Dorchester, SC
Thanks for looking in - I've got an 89 Max I've had for about 13 years and have never done any carb work. Last year I noticed it ran like it had bad gas - muffled sound etc. I drained tank, I think I put some carb cleaner stuff in it and it ran ok. This year it sounds and acts much worse - took awhile to even be able to give it throttle w/out it shutting off?! Changed plugs, fresh fuel, checked fuel filter and found what seemed to be small rust chips?? in filter - cleaned those out and will run now but sounds very muffled and will not hold idle w/out mid-choke or some throttle. Thanks for sticking w/ this long post -- Is cleaning the carbs the same as rebuilding it? I imagine I'm experiencing carb problems but is there some adjustments to try or recommended carb cleaners that might work b4 having to learn how to tear it apart?! Thanks again
 
Thanks for looking in - I've got an 89 Max I've had for about 13 years and have never done any carb work. Last year I noticed it ran like it had bad gas - muffled sound etc. I drained tank, I think I put some carb cleaner stuff in it and it ran ok. This year it sounds and acts much worse - took awhile to even be able to give it throttle w/out it shutting off?! Changed plugs, fresh fuel, checked fuel filter and found what seemed to be small rust chips?? in filter - cleaned those out and will run now but sounds very muffled and will not hold idle w/out mid-choke or some throttle. Thanks for sticking w/ this long post -- Is cleaning the carbs the same as rebuilding it? I imagine I'm experiencing carb problems but is there some adjustments to try or recommended carb cleaners that might work b4 having to learn how to tear it apart?! Thanks again

You will want to dismantle them for cleaning. When you do, buy new gaskets & o-rings....and anything else you find wrong....and re-assemble with the new stuff. That will take care of the carb issue.

Also sounds like your tank is rusting and that's a whole seperate issue that needs to be dealt with at the same time or the carbs will just get dirty all over.
 
Johnny Glenn: Welcome to the Forum... Have you drained your carbs? You may find some of those rust particles will drain out too. Sounds like atleast one carb has the low speed circuit blocked... Draining the carbs may help if you can flush out the particles. You may need to do this more than once... I don't know where you live but adding Sea Foam to your gas will help keep the carbs clean as well as help stabilize the gas / fuel...

Cleaning is not the same as rebuilding because many of the rubber parts and so forth may still be good. Search here for Pea Shooter and Shotgun Procedures in the Carb / Tuning Section. Those procedures may also help you...

Added, or what dan-o said if my suggestions fail...

Good Luck and Post back your questions or results...
 
Well in my experience, if you found rust flakes in the fuel filter you need to take a good look inside your fuel tank! If there's any rust in there it's only going to get worse, and there's only one cure: you must remove, clean and treat (coat with appropriate product) your fuel tank, or replace it with a non-rusted one.
As long as there's rust in there, it will get through any filter you throw at it, and clog up your carbs, collecting in the fuel bowls. Eventually it will stop your needle valves from closing, and then your bike will run as if on 2 or 3 cylinders, smell like gas is escaping, do about 50 miles to a tank and you will find gas coming out of the exhaust headers.

Once your tank is treated (if rusty) then you're prolly best off removing and cleaning your carbs thoroughly, it's not that difficult just follow my cleaning carbs threads with pictures. Then you can also renew any rubber that may have perished in the 13 years..
 
Well in my experience, if you found rust flakes in the fuel filter you need to take a good look inside your fuel tank! If there's any rust in there it's only going to get worse, and there's only one cure: you must remove, clean and treat (coat with appropriate product) your fuel tank, or replace it with a non-rusted one.
As long as there's rust in there, it will get through any filter you throw at it, and clog up your carbs, collecting in the fuel bowls. Eventually it will stop your needle valves from closing, and then your bike will run as if on 2 or 3 cylinders, smell like gas is escaping, do about 50 miles to a tank and you will find gas coming out of the exhaust headers.
Once your tank is treated (if rusty) then you're probably best off removing and cleaning your carbs thoroughly, it's not that difficult just follow my cleaning carbs threads with pictures. Then you can also renew any rubber that may have perished in the 13 years..

+1, the secondary problem is your carbs, the cause of your problem lies within your fuel tank. You need to resolve the rust issue in your tank first by coating it or having a shop (radiator shop?) coat it for you. Then you can move downstream by changing the filter, checking the fuel pump, and finally the carb to rectify the problems the rust has caused you there.
There are write-ups on removing the tank, checking the fuel pump, and lastly NaughtyG's great series on carb r&r.
Once you get this all working normally again get a good carb sync and you should be good to go!
 
My local radiator shop cleans and coats MC fuel tanks for $50-100. The coatings that you buy will cost at least $30. Just something to keep in mind.
 
My local radiator shop cleans and coats MC fuel tanks for $50-100. The coatings that you buy will cost at least $30. Just something to keep in mind.

That sounds like a good price Mike! Have you ever had one done by them...I wonder how long it lasts.

Might be a good preventative maintenance project for next winter on '99, I wouldn't think it would be bad thing.
 
That sounds like a good price Mike! Have you ever had one done by them...I wonder how long it lasts.

Might be a good preventative maintenance project for next winter on '99, I wouldn't think it would be bad thing.
The Rad shop by me does them to but they charge 89 bucks to clean & seal. I have had quite a few done the first one I had done was about 5 years ago. I sold the bike about a year ago & it still looked good .
 
That sounds like a good price Mike! Have you ever had one done by them...I wonder how long it lasts.

Might be a good preventative maintenance project for next winter on '99, I wouldn't think it would be bad thing.

No, never had a fuel tank done by them yet, only radiators. I would not coat the tank unless it was absolutely necessary.

You would think someone could come up with a way to coat the inside of a tank with plastic so you would never have to worry about corrosion or a coating peeling off:confused2:
 
No, never had a fuel tank done by them yet, only radiators. I would not coat the tank unless it was absolutely necessary.

You would think someone could come up with a way to coat the inside of a tank with plastic so you would never have to worry about corrosion or a coating peeling off:confused2:

or just make an oversized plastic gas tank! hehe

i need to start hounding my brother about that
 
i'll talk with him soon about it, hes just getting his stuff up and going.
 
I'd also talk to vendors like Sean @ Morley's Muscle, Tom @ Cycle One-off and John @ PCW they would already have a established Vmax customer base. I'm sure they would slap a plastic tank in one of their chain drive conversions rather than do all that cutting and welding on the stock tank.
For myself I will want a 10 oz bigger tank than Kenny has for when I do my 3" swingarm extension.:biglaugh:
 
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Yea, we are getting another gallon when we extend the tanks to match the extended arms. We have them blasted while they are cut open to get them nice and clean inside.

Sean
 
Thanks everybody for the great advice - I thought I had checked the instant email notification for responses and I was wondering why no help?! I decided to check on thread and here ya'll were hard at it! Thanks! I'll start w/ the tank - any good links w/ pics on tank removal and can I flush the fuel pump or what should I do on that? BTW - where is the fuel pump at - any links on that project? I've never had to do much but enjoy this bike over the years - I have the owners manual but of course that doesn't have much info. Is there a good tech guide like a Haynes manual for the VMAX? Thanks again
 
Thanks everybody for the great advice - I thought I had checked the instant email notification for responses and I was wondering why no help?! I decided to check on thread and here ya'll were hard at it! Thanks! I'll start w/ the tank - any good links w/ pics on tank removal and can I flush the fuel pump or what should I do on that? BTW - where is the fuel pump at - any links on that project? I've never had to do much but enjoy this bike over the years - I have the owners manual but of course that doesn't have much info. Is there a good tech guide like a Haynes manual for the VMAX? Thanks again

Check the how to section. There is a thread on fuel tank removal.
Pump is up high, not mounted in the tank. Its under the faux.

Tank has drain plug under it. Or you can siphon it out. No mess that way.

As far as flushing the pump I never heard of anyone bothering to do that but it would be easy enough with some hose and a couple containers. Fill one container with clean fuel. Run a hose from it and connect to pump input. Run a hose from pump output into an empty container. Cylcle the key multiple times or, if you want to flush a lot of gas, hook it up to a 12V source and let it run.

If you have rust either buy a kit from POR 15, Caswell, or take it to a good radiator shop.
 

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