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i took my betsy to the store for gas she did good , i still thinnkn i need to change my vac adavance,,i used to see it move when i reved it up and now i dont , anyway the temp sitting there at idel is 180 and oil pressure is about 30, soon as i rev it any at all it goes to 40 ,, that could be oil i am running 10w40 for now i am going to change the oil after a little while and go to 30w i guess , when i turn it off now you can here the oil draining back , i guess thats good means oil is up top ,, starts real good just a bump ,, so almost there, i want to thank all the guys that help me through this ordeal

thanks again

Might check the line at the advance when the engine is running.

See if there is vacuum at the advance when the engine is revved.

If the wrong carb base plate gasket is used it could block the passage in the base of the carburetor to the line.

will do
thanks

You should only have vacuum when the engine is revving.

At idle there shouldn't be any.

What do mean by revving?

When you are accelerating at any rpm, the vacuum will be relatively low. When you are running smoothly at just about all normal speeds/rpm (revolutions), you should have a high vacuum reading.

At idle, you should have a high vacuum reading.

The vacuum advance is ported vacuum on these old sixes the best I remember. Which means for there to be any vacuum to the distributor, the throttle plate should be off idle and least enough to allow vacuum to pull on the the advance.

You are right, the vacuum will be low, depending on how the engine is revved.

The best way to feel it is to actually goose the engine a bit.

You are also right that at idle the vacuum would be highest, but with the throttle plate closed the port to the vacuum advance line does not get any vacuum.

At higher loads and speeds the vacuum advance actually does very little on these sixes so long as the throttle is wide open. The mechanical advance does most of the work as the engine speed increases.

Pulling a long steep hill under a load with the throttle wide open would leave no vacuum to work the vacuum advance, so the mechanical advance keeps the timing up.

At least that's the way I was taught it worked.

If I'm wrong, ignore all I said. LOL

Thanks for correcting us, Roy,

The vacuum to the vacuum advance is indeed different from the vacuum produced at the carburetor/intake-manifold.

There have been a few vacuum advance posts lately. Before replacing a non-moving vacuum advance unit, I disconnect the line at the vacuum advance unit and attach the line to a rubber hose connected to a vacuum gauge. Then, rev the engine and check the vacuum readings as the revs go up and down. If the readings fluctuate but the vacuum advance had not been moving, . . .

Well..... if I got it right, I might as well go to bed now. Doing this with a massive head ache is for the birds.

So may not have been very clear to start with. May still be about as clear as mud.

....vroooom....

....vroooom....


My oil gauge also increases off idle, I thought that was normal

I hope it does.

roy that video is how mine used to do and now it dont .. i even tried to suck on the metal line at the carb tring to get it to advanve and it didnt , i did a check on the metal line and no leaks so that tells me that the diaphragm ius bad ( no? ) i will try hooking my guage up the metal line that goes to the vacuum adavanve and see if the carb is pulling , what should it be when revving up , i guess it should bounce up and come down when the engine come down ??

thanks guys

I don't know if you can created enough suction by mouth to move it. But if were leaking, you should have felt the air coming through the line.

I think you would have better luck borrowing or buying a hand held vacuum pump to test it.

I can't get the video to work with Windows Media Player so can't comment on it.

But the dist should turn then the throttle is opened.

when sucking on the metal line at the carb end nothing happens , kinda like open line you know ? i am still going to put my guage on the metal line at the dizzy end to see if there is vacuum created by carb ,,
thanks

If you can't create any vacuum at all on the line then the advance is likely bad, or there is a pin hole in the line between the carb and the advance.

Even sucking on it you should feel resistance.

ok i just did a few checks
1st is i pump my guage on the metal line at the carb and running at idel i had about 0 to 5 on vac guage when i revved it up it went to about 10 to 15
2nd i unhooked the metal at the carb and i pressed in on the diaphragm with my fingure on the opening of line and i let the plunger go and it came right back ,, so i say the diaphragm is bad too bad i have to change the whole thing and not just the diaphragm

thanks

Are you running these test at the carb? Or at the distributor?

If you have vacuum at the distributor when the throttle opens, then you have a bad advance.

Sounds like that's what you have.

just found a whole dizzy from a 57 235 for 25 bucks here local , he said it was good when removed , i will check it when i get there by pushing in on shaft and plugging the port and see if it moves back

thanks

well no good wrong dizzy that one was one with a hose port not the fitting port and it looked real bad
guess i have to order one

Probably a later model distributor. I think (and may be wrong) but all the 235 distributors with vacuum advance had the fitting on them, not a hose connection.

Likely he gave you one for later 230 or 250.

Great idea with the video.
It clearly shows how the vacuum advance is supposed to work. With the exhaust note, you can readily see that it's the throttle opening the vacuum port that actuates the advance. I think we should keep that link handy and offer it in the 1st reply to anyone who asks about vacuum advance. It would be cool to have an equally clear one of the timing ball.

regards,
Leon

Thanks Leon
I added a second link to the video that does not require quicktime.

lilrobo
What kind of carb are you using on your 235?

yeah i am glad i didnt buy it ,, i guess i have to order one i hate that , i like going and buying things lol

thanks