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Discussion Starter #1
I just removed the restrictor plate and opened up the 'bell mouth" on my '05 790 Bonnie...
It had 115 mains w/ TOR's, K&N, -AI, -Snorkel...
I went to 120 mains, left the 40 pilots in, it had two shims that I left in it. One on the top of the stock needle and one on the bottom.
She fired right up, then after about 20- 30 seconds she dies out with no throttle response. I checked the float level with the bowl off and on the the bike w/ clear tubing. It appears that I may have disrupted the float level when I took the carb's off to get to the stripped philips heads. I left the throttle cables on and just pulled the carb,s out the left side.

What is the best way to check and adjust the float level?
With carb's on or should I remove them again?

42 pilots as well as a new D-tool on order. The D-tool that was given me is trash. Got other jets on hand also.

What do you think? Try and adjust the float level on or off...
Can anyone give me some tips?
Does this sound like I'm on the right track or is it something else?
Intake rubbers are tight, solid blanking caps...
 

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Please refer to the shop manual. One must remove the carbs and turn them up-side down to check and adjust the float level. Make sure all jets and orfaces are free of dirt. Carb. cleaner and a air compressor also helps in the clean-up process.
 

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Something's not right. The only way to check is as described above.

What's up with your shims? They get slid on the shaft of the needle so that the needle sits higher in the main jet. Putting one "on top" really does nothing.
 

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Discussion Starter #4
Something's not right. The only way to check is as described above.

What's up with your shims? They get slid on the shaft of the needle so that the needle sits higher in the main jet. Putting one "on top" really does nothing.
Yes, thats the way I found them when I re-jetted. I bought it w/ the TOR's and -AI ,so the dealer set it up that way for the previous owner.

I found one shim under the plastic needle holder on the piston assembly , and one on the top of the needle holder and the needle.

I'll remove the one under the needle holder...

I wonder why the dealer did it this way?

This is the first time I've been inside the carbs...
 

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Discussion Starter #6
Please refer to the shop manual. One must remove the carbs and turn them up-side down to check and adjust the float level. Make sure all jets and orfaces are free of dirt. Carb. cleaner and a air compressor also helps in the clean-up process.
Cleaned w/ carb cleaner and compressed air...

It is my understanding that you don't want to "compress" the spring loaded rod when you measure. Just till the needle valve seats.
Correct?
Should I bend the float tab w/ a small screw driver or what's the norm?
 

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Discussion Starter #7
Incompetence, perhaps? :knockknock:
That is one more example of why it is good to do it yourself.
It's so sad I have no real dealer support here locally...
Just you guys...
The bike was originally purchased new from a dealer in Phoenix...
Tucson dealer doesn't even carry jets!
I got them at the Honda (sorry) dealer...

I love working on my bike, and I'm learning a lot more about it.
Just hope I can nail this problem.
Sure can't afford shop rates.
Wanna keep modding and ride!
 

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Take off both shims--it doesn't sound like either one is in the correct place. You may not need them anyway, and if you do, you can always add one later by just removing the top of the carb.

Tell us more about the specifics of how you rejetted. I do NOT suspect the float level to be your problem. The carb bowls are vented to the atmosphere and if that vent is plugged, they can flood big time. This vent is an open "T" somewhere on the top of the carb assembly with the closed parts of the "T" going to the carbs via hoses. Make sure this wasn't compromised when you partially removed the carbs. This description is for a non-CA emissions bike. For CA emissions, the carb bowl vent goes to the charcoal canister.

The main jets screw into the needle jet holder which sometimes unscrews when removing the main jet if the needle jet holder is not kept from turning by use of a backup wrench. When this happens while changing the main jets with the carb on the bike, the needle jet can fall out when the needle jet holder is removed. The needle jet is a small brass sleeve. I would suspect the carbs would flood without the needle jet, but I don't know for sure as I have never tried to run the bike without them in place. Also, the needle jet only goes in correctly one direction and that direction is not readily apparent by looking at it. If one is lucky enough to have ditched the airbox, then it is a simple check to look into the throat of the carb and one can see the needle jets protruding slightly into the throat of the carb encircling the needle (IF they are installed and installed correctly.

This is a very long-winded way of saying I think you might want to look for other things that can cause the carbs to flood before settling on the problem being the float adjustment. I even read where one member confused what he had read and "adjusted" the pilot screws by screwing out the PILOT JETS 2.5 turns--this did cause some flooding.:D
 

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Discussion Starter #9
Tell us more about the specifics of how you rejetted.
The main jets screw into the needle jet holder which sometimes unscrews when removing the main jet if the needle jet holder is not kept from turning by use of a backup wrench.
Thanks Larry,
I used the backup wrench...
Double checked every thing three times by removing the top cover and float bowl to check every thing...
Even changed plugs...
They were pretty wet and black after the first start up and run...
Always like your valuable info...
 

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Rather than buy another D-tool, I would recommend you put the money towards buying a pair of NewBonneville.com's thumbscrew pilot screws. This makes it a lot easier to make adjustments on the fly and without burning your hands on a hot engine. I also found that the fairly soft D-tool I previously used rounded off and am a lot happier with Brent's thumbscrews. His have a taper that is a replica of the originals so that the number of turns out used is comparable to the stock screws. Some of the others available are intended for use on Harleys and have a different taper.
 

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They were pretty wet and black after the first start up and run...

if you didn't have a spark miss, then the wet is from rich.

IF it's floats:
floats need to float...make sure you don't have one with a pin hole full of gas
debris in the float valve seat(s).
if the valve itself has a bouncy on the contact end...make sure it's bouncy.
...possible, but unless someone was harsh, the float level is usually safe from tampering.


my suspicion:
it sounds to me like 120's with shims and an eye on 42 secondaries is ambitious...many make this mistake when numbers lusted for all out performance doesn't jive with everyday riding habits/engine requirements.

also check the enrichment circuit (choke) to see that the seat is shutting off it's gas circuit.

a hole in the CV diaphram won't lift the slide and would also act like a constant choke...or if the sync is way out and one cylinder is leading the other.


look at the plugs...is it both? (too much jets or enrichment valves leaking)
or is it only one (one leaking float, one float valve, loose jet, sync)

first thing I'd do is take the carbs apart and blow all the orifaces out with compressed air...make sure the emulsion tube holes are all clear, and needle guides are tight in the carb body.

I'd be tempted to go back to 115/40 jets and loose all the shims to eliminate someone else's misjudgement...then build from a solid starting point.
I think you're out on someone else's limb without a map.

wet plugs on the surface suggest rich mix,
but it can also say intermittent spark, or low compression. this can be tricky.

answers are only as good as the accuracy of the information given.
 
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