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Quick background. I had a '98 from '01-'06 then bike less till last June when I got my '97. One owner, 18k, garage kept (6 months at a time), west coast, never down. Great bike.

I had issues off the get go with pilot jets. 2 weeks in I tore of the carbs and cleaned out all the jets and bowls. Instant improvement. I just crossed 21k today and have been have the same issues the past month where it's starting to lag on the initial throttle. Tells me pilot jets are do for another cleaning.

Is this just something I need to do every 3k? I know I did it twice with my '98 but it was because I dropped it twice and it had been sitting for 6+months for $ for repairs.

It runs rich. I only say this because I get back pops when down shifting hard and most revs and I can smell it in the exhaust. I put a K&N on it back when I went through the carbs the first time which should lean it out but no.


When I pull the carbs apart this time should I put new jets in or do anything else? I've done a full rebuild when I was a kid on some old quadrajet from my '67 c-10 but never done a 4-carb bike rebuild.

Leaning out the jets so I'm not running so rich? How would I do that?

I don't care about the MPG but my '98 (11k-21k miles owned) would get 150-180 per tank and I'm only getting 120-150 on my '97. Hence the rich exhaust smell.

Any other suggestions would be great. Thanks!
 

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You shouldn't have to clean them that often. You might want to drain the tank and check the strainer. It may be bad. If so I'd remove it and add an inline filter between the carbs and tank. I'd also go back and pull the carbs and remove and reverse blow all the passages. Check your jets and clean as needed with soft toothbrushes and or toothpicks
Don't use any metal or you'll take a chance ruining them. If you can get it Yamaha Combustion Chamber Cleaner is magic. Just be in a well ventilated space and keep it off the plastic and rubber parts. If your patient and carefully you can pull the whole bank of carbs together
This will save panic cussing and mental issues because a small spring just shot out the door into the tall grass. (Don't ask it'll just cause convulsions).
Take your time do one at a time so you dont mix or (convulse) dammit loose things.
Good luck (twitch twitch) I need a drink now! Lol
 

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Discussion Starter #3
You shouldn't have to clean them that often. You might want to drain the tank and check the strainer. It may be bad. If so I'd remove it and add an inline filter between the carbs and tank. I'd also go back and pull the carbs and remove and reverse blow all the passages. Check your jets and clean as needed with soft toothbrushes and or toothpicks
Don't use any metal or you'll take a chance ruining them. If you can get it Yamaha Combustion Chamber Cleaner is magic. Just be in a well ventilated space and keep it off the plastic and rubber parts. If your patient and carefully you can pull the whole bank of carbs together
This will save panic cussing and mental issues because a small spring just shot out the door into the tall grass. (Don't ask it'll just cause convulsions).
Take your time do one at a time so you dont mix or (convulse) dammit loose things.
Good luck (twitch twitch) I need a drink now! Lol
Perfect. Not sure how me owning a '67 c-10 I didn't think to check the tank and/or the screen/filter.

I guess when I had my '98 each time was replacing plastic and more so my tank had been dry and no reason for sludge build up.

In the spring issue (twitch twitch). I've been there. Haha.

All 4 carbs come out at once and I only open and clean one bowl and jet at a time.

Are there any adjustments I should make on the jets?

If I'm getting some sediment from the bottom of the tank it wouldn't explain running rich. Well maybe if my pilot jets are getting clogged first then my main jets dump gas because that's how I throttle. That would cause a rich run.

Perfect! Thanks!

Correct me if that doesn't sound right. I'll update after I tackle it this weekend.

Drinks are on me!
 

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If you get a smell of unburnt fuel perhaps it's flooding on one or more cylinders (poor MPG too). Check the needle valves (shut off valves). I have found in the past that flooding can cause a stall when giving it handle! Not sure why!
 

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This is where the PGMFI is vastly superior to carby's;)....... I used to strip and clean my carby's on a FZR1000 every 10,000kms - I would dismantle the complete set and lay all the bowls, jets, floats and needles and vacuum slides in order , cleaning them and air blasting the jets clear. The main body of the carb's had small tubes that need to be cleaned with air blasts....... not sure of BB's carbs but they must be similar to the Yamaha carbs. Wash in petrol and blow all orifices clear (you'll see fuel mist and probably be blasted with petrol spray so cover your eyes!).

Doing just the jets may not have cleared your blockage. Also, you will want to check that all the float needles are springing cleanly and don't have wear marks on their rubbery tips. They all should sit level on the carby body when you place the floats back on the body and invert it so they sit closed like when the bowls are full of fuel....... they may need adjustment, and if so, will need retuning and balancing. Your poor running may also be due to carbs being out of synchro.

It's high tech compared to a car carby and you may need a professional to get it tuned just right. It will stay in tune for a very long time, so it can be money well spent this time.......

(y)
 
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