carbed monster won`t start, fuel isse

[Howie]

Also, did you pull the spark plugs and look for fouled plugs?

[koko64]

A change of plugs is a ten dollar tune up and worth doing[thumbsup].

Possibly, clagged jets or float needles glued shut by stale fuel as DP suggested. I've seen pilot jets completely sealed with fuel wax and float needles glued up in the closed postion by jelled fuel.

[samuraibiker]

hey guys

plugs were on the dark side...a little too dark for my liking so gave them a good clean with a wire brush and checked the gap with feeler guages...plugs are only 6 months old.

hey ducp..... i havent tried that as I can see gasoline in the venturi but I will try that next. How much fuel per venturi? a few mililiters?

[DuciD03]

have you tried squirting the carb with "carb cleaner"? try that first ...

report back

next try

use caution this may be a little risky

.... try ...removing both plugs; clean plugs .... put a little gas (few drops) directly in the plug holes; reinsert plugs; cross fingers ... press start ...

repeat maybe increasing gas

report back

[ducpainter]

hey guys

plugs were on the dark side...a little too dark for my liking so gave them a good clean with a wire brush and checked the gap with feeler guages...plugs are only 6 months old.

hey ducp..... i havent tried that as I can see gasoline in the venturi but I will try that next. How much fuel per venturi? a few mililiters?

Yes, a few drops, 2 or 3, of fresh gas in each with clean/fresh plugs.

If it doesn't at least fire, then fuel is not the issue.

[samuraibiker]

thanks again for the advice.... will try that asap

[DuciD03]

thanks again for the advice.... will try that asap

I'v been waiting to hear ... but no posts; hope you didn't blow yourself up with gas ...

[samuraibiker]

hey guys

sorry for the slow reply..... mad mad snow here in japan so have been doing a lot of snowboarding.... my other passion besides motorbikes and jazz!

anyway....fuel in the cylinders and she fired up!!!  so its deffo a carb issue..... got out the trusted haynes manual but to be honest, it really isnt that clear about how to remove the carbs so any advice would be appreicated, especially detaching the throttle cables from the carb itself ( this is the point that Haynes is very vague about )

[koko64]

Leave the cables on the carbs and detach them from the throttle barrel instead. There is a bit of work getting the carbs off as the airbox/battery box must come off first.
Maybe you can leave it all in place and working from underneath remove the float bowls and then the slow jets if you are careful. Moving the oil cooler out of the way will help.

[samuraibiker]

hey koko

i was thinking the same.... with my vespa i can get to the jets without taking the carb off. I have a 400 so no oil cooler. Is it possible to access both pilot and main jet from beneath? I have checked many threads about duc carb cleaning and they all recommend removing the carbs.

Your tip about removing the cables at the throttle end is a good one , looks much easier that detaching them from the carb itself.

so, next step.... float bowl covers off, pilot and ( hopefully ) main jets removed and cleaned whilst carb is still attached, reassemble and fingers crossed!  If no joy, carb comes off the bike for more detailed cleaning.

[ducpainter]

It isn't impossible to work on the CV carbs installed on the bike. It's the way I was taught.

Helps if you have a lift.

Main jets are not the issue...pilot jets.

[koko64]

Pilot/slow jets have pin holes to flow through and are easily waxed shut by old fuel. It would be difficult to play with the main jets with the carbs in place and would be easy to make the beast with two backs up. Just try clearing the pilot jets to get the bike going and pour some carb cleaner into the tank.

[ducpainter]

Pilot/slow jets have pin holes to flow through and are easily waxed shut by old fuel. It would be difficult to play with the main jets with the carbs in place and would be easy to make the beast with two backs up. Just try clearing the pilot jets to get the bike going and pour some carb cleaner into the tank.

You can do mains too...really.

[koko64]

I know. I've done them with the carbs in place, but I'm trying to keep it simple for SM to stick to the essentials. The main jet holes are pretty big and usually carb cleaner in the tank and a good ride should do it, but I have seen quite a few sets of pilot jets waxed shut.

[ducpainter]

I absolutely agree he should ignore the mains for now and concentrate on the pilots.

Pilot/slow jets have pin holes to flow through and are easily waxed shut by old fuel. <snip> Just try clearing the pilot jets to get the bike going and pour some carb cleaner into the tank.

I absolutely disagree with...

<snip>It would be difficult to play with the main jets with the carbs in place and would be easy to make the beast with two backs up.