Vac psi?

[Lord Grizzlon]

im noticing that my vac doesnt move when bike is on. unit is good whn i put finger over hole. it sucks and stays closed. anybody kno wht the psi is supposed to be whn wrkin properly?

[TopCatGr58]

Hey there Lord,

You're giving us some mixed information here. You say your vac. unit is good, yet, you describe putting your finger over the vacuum hose line or port and only verify that you "have" vacuum. You need to apply vacuum to the hose that connects to your vacuum advance unit, and then watch to see if the plate turns and the little arm that the vacuum piston moves/pulls on will move, or if you're sucking on the attached vacuum hose, do you just get a lot of air, are not able to actually create a vacuum with the vacuum unit. If the latter, then the unit may be damaged, with holes in the diaphragm and may need to be replaced. Could also have cracks/holes in the vacuum hose itself, check it thoroughly!

If you can create a vacuum with your mouth on the hose, but the plate doesn't turn, try moving the plate by hand. The grease can get caked, gummed up, you may need to clean your advance plate, relube and ensure that it spins/turns easily, and then the vacuum unit should be able to move it, IF the vacuum diaphragm is any good!!! HTH.

T.C.

[Lord Grizzlon]

Originally posted by TopCatGr58
Hey there Lord......

You need to apply vacuum to the hose that connects to your vacuum advance unit, and then watch to see if the plate turns and the little arm that the vacuum piston moves/pulls on will move....
T.C.

Did that. but it doesnt move when the engine is runnin. I thinkin of runnin a line from the diaphram to a carb nipple.

[Ken Talbot]

You won't want to connect to a nipple on one of the carb boots - the vacuum pulses need to be dampened or the advance plate will clack back and forth erratically. If you disconnect the hose from the carb nipple and place your finger on the nipple, can you feel vacuum? I'm thinking maybe the smal orifice that is meant to dampen the vacuum pulses is plugged???

[Lord Grizzlon]

let me rephraze... the vac is not pullin the octopus, but unit is good. im thinkin of running the oct to the carb nipple.

[Geezer]

Originally posted by Lord Grizzlon
let me rephraze... the vac is not pullin the octopus, but unit is good. im thinkin of running the oct to the carb nipple.

First off lets make sure we're on the same page with the vacuum hoses. The number 2 carb has a vac outlet for the advance and the octopus connects to a vacuum nipple on one of the intake manifolds.

You can take the octopus apart and clean it. A little corrosion can keep the valve from opening and often cleaning it will solve the problem.

Geezer

[John]

Or you can just eliminate the octopus, and be rid of potential leaks, and carb/airbox flooding.

[Lord Grizzlon]

Originally posted by Geezer


First off lets make sure we're on the same page with the vacuum hoses. The number 2 carb has a vac outlet for the advance and the octopus connects to a vacuum nipple on one of the intake manifolds.

Geezer

and that..... was the prob. tht fixes my fuel starvation prob. now i can ride longer than 3 blocks w/ o havint to stop and re-prime the carbs.

Fuc***g bike shop. u would figure tht they would notice

[Geezer]

Originally posted by Lord Grizzlon



and that..... was the prob. tht fixes my fuel starvation prob. now i can ride longer than 3 blocks w/ o havint to stop and re-prime the carbs.

Fuc***g bike shop. u would figure tht they would notice

I'll bet your engine runs better too. It would have been getting way to much advance with it hooked up like that.

Geezer

[Lord Grizzlon]

NOW SHE GET TOO MUCH GAS. WHN IDLING, SHE REVS OUT OF CONTROL. IVE CLEANED, AND REJETTED THE CARBS. 1 SIZE UP---CUSTOM EXHAUST, K&N--- BUT NON STOP REVVING

[Lord Grizzlon]

OH YEAH, W/ BACKFIRING

[Ken Talbot]

Could it be a simple as idle adjustment screw (the one 1/2" diameter in between carbs #2 and #3 where it is hard to find and adjust) needing to be adjusted down? You do not set the idle speed adjustment with the adjusters on the cable. JAT...

[Geezer]

Originally posted by Lord Grizzlon
NOW SHE GET TOO MUCH GAS. WHN IDLING, SHE REVS OUT OF CONTROL. IVE CLEANED, AND REJETTED THE CARBS. 1 SIZE UP---CUSTOM EXHAUST, K&N--- BUT NON STOP REVVING

It sounds like an air leak, I'd pull the manifolds, clean and reseal them.

Geezer

[Lord Grizzlon]

thts wehat i thougt also, geezer. but.... ken was right...i have to remember KISS- keep it simple ....stupid.