What am I missing ???

**sharky** · 08-03-2009, 06:02 PM

The bike runs fine on the bench....revs clean....no smoke etc...
When I try a test ride theres a huge lack of power/won't rev.
Checked all coil resistances and connections, spark jumps 6mm as per manual,float height set as per manual.
Carbs are jetted with factory pro kit for my bike, middle size main jet used. 2 x K&N filters, 4-2-1 and Supertrap can fitted, new Pingel fuel tap.
And yeah, yeah..lack of power,Yamaha etc etc...hahaha....

**EFE 1230** · 08-03-2009, 06:13 PM

Tried a spin without the filters??

**Cruisecontrol** · 08-03-2009, 06:25 PM

Vacuum hoses?

**sharky** · 08-03-2009, 06:56 PM

Weird......Cyl 1, slightly sooty plug....Cyl 4, white deposits and slighlty golden appearance to the metal surrounding the electrode...
As if 3+4 aren't getting enough fuel...
Gonna pull the carbs off again tomoro after work but first I will run the motor for a while and then drain each float bowl individually and measure the amount in each.

**Benz** · 08-03-2009, 07:47 PM

What about the airlines for the bowls?? If they're blocked,or kinked, would explain it....

**Docktor** · 08-03-2009, 08:39 PM

I had a pingel tap on mine first, worst piece of crap ever mate, Ya cant trust ya needle and seats at the best of times and with the pingel it got no vacuumn shutoff. I know its not ya problem but if ya do use a pingel turn the tap off after every ride. or better yet use a proper tap. and make sure ya vac line u not using now is blocked up and blah blah

**Large** · 08-03-2009, 08:50 PM

quote:Originally posted by sharky

The bike runs fine on the bench....revs clean....no smoke etc...
When I try a test ride theres a huge lack of power/won't rev.
Checked all coil resistances and connections, spark jumps 6mm as per manual,float height set as per manual.
Carbs are jetted with factory pro kit for my bike, middle size main jet used. 2 x K&N filters, 4-2-1 and Supertrap can fitted, new Pingel fuel tap.
And yeah, yeah..lack of power,Yamaha etc etc...hahaha....

Do you mean it runs fine with no one sitting on it- but when you ride it it's fucked?

What's changed? are you squashing a fuel or airline? Shorting some wire? Got your nuts in front of the airbox inlet?

**sharky** · 08-03-2009, 08:51 PM

Yeah, always turn it off doc....bought the first one as it was cheaper than replacing my leaking xjr tap.
After wasting money on a dribble flow hiddly tap I bought another pingel....it will be needed when he new motor is built.
All vac lines are blanked off...haven't got any tubes from the 2 over flow/vents on the carbies...but then never have had.

**evad** · 08-03-2009, 09:52 PM

Hey Russ, bummer!! Pull the drain plugs out of the carb bowls and rin them into a container and see how much fuel is coming through. Could be a breather blocked on the tank and you are getting a vac lock or debris blocking the fuel tap?

**_M_** · 08-03-2009, 10:19 PM

Had simular when the fuel pump power was disconected.

**TurboKat** · 09-03-2009, 12:39 AM

Check for rags in the inlet ports

**sharky** · 09-03-2009, 07:06 AM

quote:Check for rags in the inlet ports

Checked ya phone for messages lately ??

**Deano** · 09-03-2009, 10:15 AM

what have you changed since it ran fine

when you say it runs shit what is happenin. cough and splutter, drop a cylinder or two, all 4 go out.

wouldnt be surprised if it is a plug issue. have you tried new plugs.

**TurboKat** · 09-03-2009, 12:04 PM

quote:Originally posted by sharky

Checked ya phone for messages lately ??

Just did, replied.

**sharky** · 09-03-2009, 06:10 PM

Well...velly interesting.....
Drained the float bowls today...into 4 matching containers...all 4 had as near as the same fuel level...however 1+2 had a good strong flow through the 3mm drain tube I used....3+4 dribbled...
Methinks the beer goes to Benz...got the carbs off...I'll work on 'em whilst watching Top Gear...great having a tv in the garage...

**evad** · 09-03-2009, 06:44 PM

so whats the go? Wasp nest?

**Deano** · 09-03-2009, 06:50 PM

you should also check that the drain is not part blocked.

do the same test with the float bowls off and operate the floats manually. use the same container and measure the amount of fuel that comes out in a certian time and see.

the float bowl drains can get a build up of red looking silt (easiest way to describe it)

you could also have a blocked main jet or something similiar. free reving will only use the pilot and abit of the needle.

also if you put the carbs back on and they still act up then take the filters off and watch the slide. you need to be able to see the position of the slide when the bike starts running shit. this will narrow down the section of the carb that is giving you issues eg- mains, needle, transitions.

while the carbs are out check the diaphrams aswell. could be a torn one or 2 that are not allowing the needle to rise.

what about the plugs, got some new ones. if so try with cleaned carbs and if no good replace plugs and retry.

**Benz** · 09-03-2009, 06:50 PM

I had the same shit happen to my slabby, ran good until I loaded it up a bit, then two carbs cut out............wasps nest in the end of one vent hose......