No tach, how to set idle speed?

[gunterm]

So being an older Chrysler that needs that 20 pole tach (I found one that still doesn't work), I don't know the idle speed so it's pretty hard to know what's going on. Is there any way to ballpark that it's idling at the right speed?

Also, it runs differently with the cowl on or off (obviously since the carb can get more air), so my question is, should I make these adjustments and quickly throw the cowl on, or are the instructions meant to have you set it with cowl off?

 

[Georgesalmon]

Re: No tach, how to set idle speed?

You really need a tach. Dosen't need to be dash mounted. One out there called a "tiny tach". ebay usually has them less than $50. You will need a tach for checking rpm at wide open throttle too. Should not run differently with the cowl on or off. No idea about that one unless the air intake ports are pluged.

 

[gunterm]

Re: No tach, how to set idle speed?

Here's the closest I got, also included a shot of the 20 pole tach

http://www.youtube.com/watch?v=jYdACgWvph0

If I'm too poor to afford a tiny tach, would this one work?

http://www.ebay.com/itm/12V-Hour-Me...551?pt=LH_DefaultDomain_0&hash=item35bba6b987

 

[Frank Acampora]

Re: No tach, how to set idle speed?

Well, first off, unless that engine has electronic ignition the 20 pole tach is incorrect. A regular tachometer is the correct application. It takes signal from one set of points and the tach is set on the back for (1) pulse.

 

[gunterm]

Re: No tach, how to set idle speed?

My cowl says "Magnapower" model # is 5591, I don't know if that is telltale of magnapower or not.

 

[jerryjerry05]

Re: No tach, how to set idle speed?

Running better with the cowl off????
There's an exhaust leak somewhere.
Or a blockage(not likley).
Find someone with a timing light that has the meter in the end.
Tiny tacks ain't that expensive.If you buy 2-3 wrong tachs the shipping back and forth would buy the TT

 

[BonairII]

Re: No tach, how to set idle speed?

Save up...and buy a tach. I almost went the tinytach route, but bought a teleflex for $20 bucks more. Tinytachs have a potted battery, so once it dies...the tach is done(unless you can dig the battery out of the epoxy and replace it.

A tach will help you run your motor more efficiently(saving gas) and help you prop it correctly(saving gas and increasing the life of your engine).

Well worth the money IMO.

 

[Jiggz]

Re: No tach, how to set idle speed?

Here's the closest I got, also included a shot of the 20 pole tach

http://www.youtube.com/watch?v=jYdACgWvph0

If I'm too poor to afford a tiny tach, would this one work?

http://www.ebay.com/itm/12V-Hour-Me...551?pt=LH_DefaultDomain_0&hash=item35bba6b987

I actually ordered one of those $15 tach that attaches to the #1 plug. I have yet to receive it but I just plan on using it as a back up or verify the main tach. I'll let you know as soon as I get it and tested. it should work though since it only measures the spark for the #1 plug which in a 2 cycle engine equates to 1 REV.

 

[gunterm]

Re: No tach, how to set idle speed?

Running better with the cowl off????
There's an exhaust leak somewhere.
Or a blockage(not likley).
Find someone with a timing light that has the meter in the end.
Tiny tacks ain't that expensive.If you buy 2-3 wrong tachs the shipping back and forth would buy the TT

That's what I was afraid of, I figured they wouldn't build an engine that needed settings adjusted with it on without mentioning that in the manual.

Where can I start looking for the leak or block?

 

[jerryjerry05]

Re: No tach, how to set idle speed?

Look in the lower part of the motor cover down inside is a rubber boot that might have slipped.
Or a small snout that sticks out the back of the motor.Possibly a seal leak there?
Or worst case,one of the gaskets under the head sprung a leak.
Start motor and look under the cowl.

 

[gunterm]

Re: No tach, how to set idle speed?

I'm assuming this is what I want to look under? I don't really see much here, except that everything is really oily. There's something that looks like a boot down in the corner, but it's attached.

 

[Frank Acampora]

Re: No tach, how to set idle speed?

Those early 55sDon't have a rubber boot for the idle relief ports. That single tube that sticks out the back is the idle relief vent. Judging by the amount of oil inside the lower cowl halves, I would guess you have a bad base gasket and it is leaking exhaust into the cowl then down the leg. It is a long job to replace the base gasket--you must completely remove the powerhead--so that is probably why it was never done.

Again, Chrysler used the term Magnapower quite loosely. These old 55 while labeled Magnapower are usually magneto or battery and points ignition. They use a standard tach but even those do not seem to work very well.

 

[gunterm]

Re: No tach, how to set idle speed?

Ah, well the big long gasket that encircles the motor is starting to deteriorate, so that must be it. Before the fuel pump went bad I was able to plane out at top speed, so I'm guessing it doesn't affect you any time except at idle. Maybe it'd be easier to drill holes in front of where the carb is and run a little tube with air filter.

You can see the gasket I'm talking about at the top of the 2nd picture.