[mag]

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I need some help with this. It must be a stuck float. I've sprayed carb cleaner in the idle circuit, ran some MMO in the tank, rapped on the float bowl. These are completely rebuilt carbs, done by Honda. The bike runs beautifully, but is only getting 28mpg. Last time i tapped on the bowl, it jumped up to 40mpg. I guess i'll have to keep trying to free it up, eh? All the other plugs read normal. I just gassed up, so will see what happens after next top up with mileage. It's still starting like its flooded.

 

[axelwik]

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Yep, sounds like a stuck float or some crap in your float valve. Other things that can makeone cylinderrun rich is a blocked slow air jet or a secondary vacuum piston stuck in the down position. Also might want to check that you're getting adequate spark for that cylinder... sometimes those plug cap resistors break down with age.

 

[mag]

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Thanks, Marco. The old fuel line was on there still. Must have sent some debris to carb. The plug cap is brand new, and i've recently trimmed the wire back and checked resistance/spark. The fact gas comes pouring out of the float drain in excess tells me its flooded. I hope i can free up the float valve/needle. I'm not pulling those carbs again!

 

[axelwik]

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mag wrote:

I'm not pulling those carbs again!

I hope you don't have to.

However, if you do have to pull them and clean thefloat valves,check for correct float height.

 

[mag]

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I've re-checked everything. TIming is bang on, so is carb-sync. I've rapped on the float bowl, drained, re-filled, sprayed tons of carb cleaner in the drain hole. The bike runs amazingly well, idles fine, accelerates smoothly. The plug just goes dry black right away. Will a stuck float clear itself up? We're going on a long trip, it would be great if the gas flow would clear this up.

 

[axelwik]

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mag wrote:

I've re-checked everything. TIming is bang on, so is carb-sync. I've rapped on the float bowl, drained, re-filled, sprayed tons of carb cleaner in the drain hole. The bike runs amazingly well, idles fine, accelerates smoothly. The plug just goes dry black right away. Will a stuck float clear itself up? We're going on a long trip, it would be great if the gas flow would clear this up.

You could try... run some cleaner through the fuel system while you're at it.

 

[mag]

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I captured the liquid run-off from spraying inside the bowl through the drain plug hole,  and poured it through a filter mesh/funnel through the fuel line into the carb plenum. I've also got MMO in the tank. I suppose i could just spray carb cleaner down the fuel line to the carbs directly.

 

[exavid]

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There's a good chance you've got a piece of junk stuckto the float needle or seat. It's likely that the only way to clear it is to do it the hard way.

 

[mag]

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Just drained the other float bowls and checked plugs for comparison. ALL of the carbs had the same volume -- about 350cc of gas, including the suspect #1. Plug #2 & 4 were a little rich looking. But plug #3 was perfect, and had the same volume of gas when drained. There's also no sign of gas in the air box anymore.

I suspect the K&N reusable air filter may be clogged from the crankcase breather hose? I put a brand new stock air filter in for comparison. Also, i turned all the mixture screws out at least another full turn, except for #3. I'll check the plugs after a ride. Methings it's not flooding.

 

[Tonys96]

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Did you miss a decimal...350 cc's of gas is quite a bit.

 

[axelwik]

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Tonys96 wrote:

Did you miss a decimal...350 cc's of gas is quite a bit.

Yeah... that's over a third of a liter. 35cc's is probably right.

 

[mag]

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Yes, missed a decimal. About 1.5 X 29.6cc measure.

 

[mag]

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Put in a new plug, filled 'er up. Got 38+mpg in the city. I've been switching off the fuel to 'flush' the bowls. Seems to be ok, though i haven't checked the plug in #1. I suspect it will be black again. Grrr.

 

[Tonys96]

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mag wrote:

Put in a new plug, filled 'er up. Got 38+mpg in the city. I've been switching off the fuel to 'flush' the bowls. Seems to be ok, though i haven't checked the plug in #1. I suspect it will be black again. Grrr.

You know it's just gonna eat away at you until you pull those carbs and check that needle and seat.

You're never gonna' feel it's reliable until you do the right thing, so just do it.

 

[mag]

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Well, ALL the plugs read perfect now, and i got 38mpg. If i get another bad plug or poor mileage, I will pull the carbs for sure. I've done enough wrenching for now. Seems to be whatever was in there is freed up. Thanks!

 

[mag]

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Oh crap. I thought the carbs had a leak at the plenum, until i pulled the air filter and found gas again in the box. Also, #1 plug black again. Guess the carbs have to come off again. I don't want gas dumping in the cylinder and causing vapour-lock! Maybe a punctured float?