Jump to content
Sign in to follow this  
illinilefttackle

USE DWELL METER&TACH ?

Recommended Posts

illinilefttackle

B) Hey guys-I'm digging out my old Dwell meter,tach,volt &amp meter (boy has it been on the shelf a long time!) QUESTION-can I use this to check and see how close my point setting is while the engine is running? If so-what should the dwell be in degrees? I know the tach will work-Help an old mechanic out here!-Thanks-AL :whistle:

Share this post


Link to post
Share on other sites
 
refracman

Its been so long that Ive had to use the dwell, I cant remember how to use one B) But a old chevy head should know how to take the reading. If nobody replies I'll dig up one of my old books and check it out.

Share this post


Link to post
Share on other sites
 
illinilefttackle

Its been so long that Ive had to use the dwell, I cant remember how to use one B) But a old chevy head should know how to take the reading. If nobody replies I'll dig up one of my old books and check it out.

B) Refrac- I remeber how to hook it up- I just have never tried to take a dwell reading on a one cylinder before- My meter has a 4,6,8 cyl setting-I have heard, if you are working on a 4 cyl, you can run it on 8 cyl setting-then take it times 2---If thats true, why couldnt you run it on the 8 cyl setting and take it times 8 for a one cylinder? I know the old chevy engines were 30-35 degress or so- but I have no clue on the 1 cyl kohler.

Dwell is the period of time the points are closed in crank rotation, in degrees. And dwell is directly porportional to point gap. All that said, I don't know what dwell is supposed to be for a 1 cyl with gap of .020.

ANYBODY know?-THANKS-AL :whistle:

Share this post


Link to post
Share on other sites
 
linen beige

Hey Al, Setting the timing with a timing light automatically sets the dwell at the proper angle. The relationship between point gap and dwell angle changes only on engines with moving point mounts such as movable distributors and spark advance.

Share this post


Link to post
Share on other sites
 
sorekiwi

Hey Al, Setting the timing with a timing light automatically sets the dwell at the proper angle. The relationship between point gap and dwell angle changes only on engines with moving point mounts such as movable distributors and spark advance.

Jim is kinda right here, - since the only way you can adjust timing on a Kohler is by adjusting the points gap, you have to decide which is more important - dwell or timing. And I would say timing is more important.

Still it would be interesting to know how much dwell you have, and what you should have. Cant help you there - I've never measured it on anything less than a 4 cylinder either. If you find out, let us know!

Share this post


Link to post
Share on other sites
 
illinilefttackle

:whistle: Guys-I appreciate your replies-But I guess I'm confused-Of course, you can't change the timing on a Kohler-except by changing the point gap. "Dwell is a function of point gap" If you change the gap,you change the timing,and you change the dwell. I was just wanting to check my point setting with the meter-just in case these old feeble fingers can't feel .020 anymore! I used the "go-no-go" method to set the points,but at best,that is tedious. BUT-if you can just hook up a dwell meter and -say your dwell should be 20 dgrees for .020 point gap-BUT- your meter says 15 degrees, you would know to reset the point gap again!

ANYBODY CONFUSED? I think we are all saying the same thing-but not coming up with any answers. I'll see what I can find out-Thanks-AL B)

Share this post


Link to post
Share on other sites
 
Teddy da Bear

Al......all I have is a related idea. Hope it helps.

This sounds familiar with what I read in the Tecumseh manual you sent.

It said that you have to find 10degrees before top dead center and set your points gap there.

I am sure it is a similar operation for kohler.

Share this post


Link to post
Share on other sites
 
WheelHorse_of_course

Al,

I don't think anyone knows the answer because that just isn't they way it is checked on small engines. That said, if it runs properly you can take the dwell and tell all of us what it was!

Everyone else,

the timing, dwell and point gap are 100% related on an engine with fixed timing (e.g. no centrifugal or vacuum advance). So any one of the three can be measured (IF you know the proper setting).

Setting the points via the timing method is most likely the most accurate. Once that is done I am sure a reference Dwell could be determine.

Share this post


Link to post
Share on other sites
 
linen beige

Al,

I don't think anyone knows the answer because that just isn't they way it is checked on small engines. That said, if it runs properly you can take the dwell and tell all of us what it was!

Everyone else,

the timing, dwell and point gap are 100% related on an engine with fixed timing (e.g. no centrifugal or vacuum advance). So any one of the three can be measured (IF you know the proper setting).

Setting the points via the timing method is most likely the most accurate. Once that is done I am sure a reference Dwell could be determine.

Well said.

Al, I think what may be confusing you is that you have too much knowledge of auto engines. On any engine with a movable point mount (timing advance), the dwell can be set at any gap and the timing then set by moving the point mount relative to the crank's rotation. On these engines the gap/ dwell has to be set before the timing can be set accurately. This can be shown by noting the timing of an engine, open the point gap slightly and recheck timing. The timing should have advanced slightly. This can't be done on these small engines, so if you set the timing by adjusting the point gap so that they open at the proper time, the gap/ dwell angle is automatically set for you- Set the gap and the timing is automatically set. All of this is, of course, dependant upon you having your crank and cam timed right.

There are at least two ways to get an answer to your original question. One is for you to use a timing light to set your timing and therefore simultaneously set your gap/ dwell, and then check the dwell and record it for future use. The other is for someone here who has the same model engine, properly timed, to check their dwell angle and report it back to you. This would have to be done on an engine with the same cam grind, as lift and duration would also alter the dwell. I would be glad to check this out for you, but I don't have any K series Kohlers larger than a k-241, and I don't know if the cam grind is the same.

Share this post


Link to post
Share on other sites
 
Kelly

Ok dumb question, how do you time these kohlers with a light? I think my newer ones have a hole in the blower housing,bottom front, I think, is that where you do it at? are the older motors the same? I've always set the points with a feeler guage, when the points were open, so I could be off a bit, and that could hurt perfomace.

Share this post


Link to post
Share on other sites
 
linen beige

Ok dumb question, how do you time these kohlers with a light? I think my newer ones have a hole in the blower housing,bottom front, I think, is that where you do it at? are the older motors the same? I've always set the points with a feeler guage, when the points were open, so I could be off a bit, and that could hurt perfomace.

Not a dumb question at all Kelly. Kohlers have a timing sight hole, either in the blower housing, or the bearing plate, depending on model. Take the plug out of the hole and rotate the flywheel through a turn ( unhook the plug wire first!). You should see two marks 20 degrees apart (K-91s only have the "T" mark and it is used for setting timing.). One is "T", for top dead center, the other is "S" or "SP" (I guess it stands for "spark"?). Highlight the "S" or "SP" mark so it will be easily visible. Hook up your timing light, run the engine between 1200 and 1800 rpms, and watch the flywheel "S" or "SP" marks through that site hole. The engine is timed right when the light flashes as the mark is centered in the hole or aligned with the corresponding mark on the housing. If the timing is off, adjust the point gap gradually until the timing is right and you're done.

Share this post


Link to post
Share on other sites
 
sorekiwi

There's a few of us ex-auto mechanics that get confused when faced with an engine missing at least 3 cylinders. :banghead:

But wait till your setting points on a Tecumseh, and come to the realisation that since the lobe that operates the points is on the end of the crank, it fires on every revolution! :wtf:

Share this post


Link to post
Share on other sites
 
linen beige

But wait till your setting points on a Tecumseh, and come to the realisation that since the lobe that operates the points is on the end of the crank, it fires on every revolution! :wtf:

So do the twins that use two spark plug wires from the coil. I don't want to say Tecumseh was maybe ahead of the times, but many auto engines now fire on each revolution to help burn off some of the emissions.

Share this post


Link to post
Share on other sites
 
rustbucket

yeah my H-60 is like that fired every full rotation hehe talk about scarry stuff.

Share this post


Link to post
Share on other sites
 
illinilefttackle

:USA: I'm afraid not too much to report about the dwell experiment-My meter is a Snap-on MT-826 ,volts,ohms,dwell,Rpms. It gave me a reading on the 8 Cyl scale(the others wouldnt read it) of about 46 degrees. What the heck that means , I don't know- I would suppose that the points would stay closed most of the 360 degree rotation of the crankshaft, but I dont know how much. It would depend on the height of lift and accelaration rate of the cam lobe. If you take this times 8 it =360----If you divide it by 8=about 6. Your guess is as good as mine.

I'm glad I took the timing reading that is correct.

:banghead: -AL

Share this post


Link to post
Share on other sites
 

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×
×
  • Create New...