18 MPG.... Yuck.. 1985 Vt1100

[Dartmech]

Air filter "looked" ok, but there was a bit of oil around the sealing rubber. Not a puddle, just enough to notice. The element did not feel oily to the touch so I don't think its soaked through.
I'll have to wait on the plugs and pipe temperature.

[Inferno]

The oil is normal.

THe pulsing of the exhaust is not an indicator of firing. If you have a dead cylinder it will still pulse.
Everything points to a dead cylinder. Pulling the carbs is pointless if you have an electrical issue.

Fire it up and check for equal temps on the exhaust. I'm sure you will find one (guessing left one) isn't firing.
Clean the plugs and then check for spark using the backyard mechanic method.

If both plugs fire, put them back in but swap the plugs so the right one is in the left cyl and the left is int the right cyl.

Post results.

[Dartmech]

When you say "right" or "left" which cylinder are you referring (front/back, sorry new to twins)? And its got two plugs per cylinder. swap both to the other side? I'll play with it tomorrow and post up.
Thanks

[Inferno]

OK, my bad....

Front/back

~LOL~

The rear cylinder is slightly offset from the front. The rear cylinder is the "right" cylinder

Two plugs per cylinder? I think I have to go look at my bike!!

Yes, swap both plugs between cylinders

[John Hopkins]

Originally Posted by Dartmech

Thanks for the help guys.
When I bought it I put my hand over each pipe and felt pulses from both.

Putting your hands over the end of the pipes and feeling the pressure pulse is going to do nothing but make the seller laugh..

You know that you are losing 50% of your fuel and it has to go somewhere..remember your bike is a four stroke..so..

suck, squeeze, bang, puff...

take away the bang and the pressure at the tail end of the exhaust will still be the same..

You need to touch the exhaust headers with your bare hands as soon as you start the bike, within 5 seconds they will get hot, if one remains cold that cylinder has no bang..

John.

[Dartmech]

I'm just about off work and ready to get into the bike when I get home, but I remembered something.
The right cylinder spark plug wire on the left hand side seems abnormally long. Enough that it goes out over the frame then back to the plug. I just thought of this and how odd it looked. Does anyone remember off hand which wire/coil terminal goes where? I'll check the manual when I get home.

[John Hopkins]

Just concentrate on one thing at a time..is the bike actually firing on one cylinder or two...then start common tests..do you have sparks on all four..do you have fuel to both pots..

John.

[Dartmech]

Left (front) cylinder is not getting fuel.

Spark present at all four wires, pulling both on the left jug does nothing. Pulling both off the right cylinder kills it, one makes it stumble. My hand still tingles from the shocks. The right jug, left side spark wire is the strongest, but it would not fire off the left cylinder even though the arcing was audible.

The plugs I could get out look normal on the right cylinder, left was a bit oily, no sign of combustion. I cranked it with one of the left jug plugs out and it barely ran; when it did it pumped HARD but there was no gas smell, put my hand over it and it came out dry.

The Left exhaust pipe warmed a tad but I could put my hand on it all day, not like the other side which started to heat up very quickly.

Ok so everything I tried told me there is no fuel getting to the front cylinder. I looked up under the tank (could not remove it at this point) and I didn't see anything out of the ordinary. Can a line be pulled off of that carb to check for fuel, or is it a rail situation.

I'm going to let my head rest for a while and come back to it.
What do you guys think?

[dano4003]

The air filter is under the gas tank and yes you have to take off the tank to get to the airbox.

[John Hopkins]

OK so you bought a bike that only fire on one cylinder, and because you couldn't tell that I'm going to guess that you have no mechanical ability..

what do we know..

the basic electrics work because the bike starts and runs..

only one cylinder fires..

You need a stick of wood and a spare spark plug..

unplug one of the plug caps and fit the spare sparkplug to the cap..then press the thread of the plug against the fins of the engine with the stick of wood.. start the engine and watch the plug for a spark..mark on a piece of paper if it sparks or not..replace the cap on the fitted plug that you removed it from and repeat the procedure with the next plug...

did the spare plug spark on all four cylinders..if yes that is the electrics sorted..replace all four plugs with new ones and see if the bike runs on both cylinders..

If no move on to the carbs..

post the answer here and we can continue..

John.