2 wire dwell meter....how to 88 4.3 omc

[milkman250]

Today I stopped at an auto shop and got a dwell meter, its a two wire meter. The guy said to hook red lead on pos side of coil and black on neg side of coil, is this rite? My reading were not consistant, I was at 39* at idle and then at 1500 rpm it dropped to 29*, then unhooked and tried again and got 36* at idle and 27* at 1500, the needle did some bouncing also. what makes me think somethin isn't right is when I switched it to the rpm switch and it was showing 425 rpms and the boat tach was reading 600, and yes I had the cycle switched on meter. Would the boat even idle at 400 rpms without lugging its butt off. 88 4.3 OMC. is what we are working with, thanks for any input, I'm new to the site and love it

 

[rickryder]

Re: 2 wire dwell meter....how to 88 4.3 omc

Red to negative side of coil and black to a good ground.... If I remember correctly.....been years since I've had to check the dwell...

 

[milkman250]

Re: 2 wire dwell meter....how to 88 4.3 omc

Thanks rick ill give that a try in morning

 

[dubs283]

Re: 2 wire dwell meter....how to 88 4.3 omc

check this out:

http://forums.iboats.com/showthread.php?t=335302

 

[milkman250]

Re: 2 wire dwell meter....how to 88 4.3 omc

Wow that's good stuff .....thanks

 

[bruceb58]

Re: 2 wire dwell meter....how to 88 4.3 omc

Assuming the dwell meter is not at fault, another reason your dwell is all over the place is because you distributor is more than likely worn. See how much play is in your distributor shaft side to side.

 

[milkman250]

Re: 2 wire dwell meter....how to 88 4.3 omc

No play side to side, but can or does the lobe on distr get worn or is it suppose to wear out that plastic looking piece on points. According to what I read on the link from last post I did not hook up dwell meter properly, going to give that a try in am, and hope lol

 

[donzi gt230]

Re: 2 wire dwell meter....how to 88 4.3 omc

Yea you were just connected wrong---and dwell will change with RPM and change a little with engine temperature (distributor temperature).

 

[bruceb58]

Re: 2 wire dwell meter....how to 88 4.3 omc

and dwell will change with RPM and change a little with engine temperature (distributor temperature).

Dwell should not move at all.

Some dwell meters hook up differently than others. Read the directions that come with the dwell meter you have.

 

[milkman250]

Re: 2 wire dwell meter....how to 88 4.3 omc

Thanks for the replys, I will post up results in the morning, and then probably post more questions for what ever I find out of spec. I'm kinda a maintence freak with my toys and like them to be right. This is our first boat and purchased it late last summer and it ran liked poo, but this year is goinna be great its come along way, thanks to this site iv learned a lot of differences between marine and automotive.

 

[donzi gt230]

Re: 2 wire dwell meter....how to 88 4.3 omc

I've yet to find a motor where dwell won't change with RPM which is why the book tells you to test dwell at cranking speed, NOT with the engine running. I've used several instruments from inexpensive analogue meters to my Snap-On PDM. For the '88 4.3 dwell is 39 +- 2 degrees OR .019 gap. Dwell is more accurate than gap of course. Generally the connection is red to - side of coil and black to ground, but check your instructions. It's almost a miracle it worked hooked up wrong and probably a good thing it wasn't one of the high dollar digitals as it may have fried from that hook-up. Anyway, I'm not wanting to start a war about dwell/RPM, just follow your manuals' instructions and you'll be OK. Once you get it set properly you can check and record what it is at idle just to make it easier to recheck at a later date. I did that with mine so I don't have to fool with disabling the ignition and can spot check it easily during a pre-trip inspection run. It may be the same as cranking speed and that will make it easy. If the readings fluctuate at a steady RPM, no matter what that RPM is, then you likely have a point or distributor problem to repair.

 

[bruceb58]

Re: 2 wire dwell meter....how to 88 4.3 omc

I've yet to find a motor where dwell won't change with RPM .

His 10? over RPM is way too much and it is SUPPOSED to be steady within a degree. A changing dwell changes timing so it needs to be steady at ALL RPMS. I am not trying to start a war on dwell/RPM but what you are saying just isn't correct.

And not sure what book you are reading from but you check dwell when the engine is running.