Timing at full throttle on the boat ??

[phillnjack2]

Re: Timing at full throttle on the boat ??

so if its showing 17 degrees at around 2500 rpm when the lever is fully at the stop and then when test with engine at 5000 its 2 to 6 degrees out, dohhhhhhhh

Ok lets see if this is right.

I get it to 17degree btdc at 2500 without butterflys opening.(idle on carbs )
Then go for a ride on the boat and just check it 5000, if it shows 17 leave it alone..and enjoy it.
BUT if it shows 15 or 13 BTDC etc then change it to 17 BTDC @ 5000 ? then this would be perfection ?


phill.......

 

[clanton]

Re: Timing at full throttle on the boat ??

I would insure the timing is set at OEM specs. These 3 cylinder 60/70 horsepower engines love to toast the middle cylinder. After all settings are complete, I would prop engine to turn 6000 with light load in boat.

 

[daselbee]

Re: Timing at full throttle on the boat ??

I understand the opinions, methods, and "gotchas" being presented here, and I surely know that everyone has their way of setting the WOT timing. All ideas and suggestions are noted and welcome. With that said, I would like to go on record as never observing this timing shift due to RPM change. I use the method I described briefly above, set the timing dead on (18* BTDC for example), and then test when on the water. I have a buddy drive, and I hang off the back with a timing light to verify. Now I know, this is prolly frowned on :facepalm:, but I do it anyway. I really have NOT seen any shift in timing due to 5k vs. 2.5k rpm. I THINK, but I am not sure, that Joe developed his method with the collaboration of OMC field service reps, and they came upon the SAFEST method, which is as Joe has posted on this site and others. SAFEST from two aspects: 1. Personal safety. Less danger of injury from flywheel and 2. If you set the timing 4 degrees back from the max spec, there is no danger of accidentally getting it TOO FAR advanced, so it is safer for the engine. All that is pure speculation, tho. Maybe Joe will pop in here and tell us the history of how the "Joe Reeves WOT timing method" came to be.

 

[phillnjack2]

Re: Timing at full throttle on the boat ??

Hi Clanton, i will definitely take your advice on this.
i am aiming to get 6000 rpm or even a touch more from this engine when finaly got the set up right.
i do believe in not over loading an engine, and i prefer letting it rev rather than over loading and lugging.


so i will set it to the 17 mark, then hang on for dear life and just double check it very quickly ha ha
(i might just try rigging up a camera and a remote for the timing light)



phill

 

[phillnjack2]

Re: Timing at full throttle on the boat ??

waiting for rain to stop so i can work on it today

phill

 

[classiccat]

Re: Timing at full throttle on the boat ??

Hi Clanton, i will definitely take your advice on this.
i am aiming to get 6000 rpm or even a touch more from this engine when finaly got the set up right.
i do believe in not over loading an engine, and i prefer letting it rev rather than over loading and lugging.


so i will set it to the 17 mark, then hang on for dear life and just double check it very quickly ha ha
(i might just try rigging up a camera and a remote for the timing light)



phill

perhaps this can be adapted for your timing light? (and you can't complain that you can't get it shipped to the UK )

Very informative thread btw!

 

[phillnjack2]

Re: Timing at full throttle on the boat ??

That wouldnt be any use to me.
i have the camera and mount,i have tripods and all sorts but i would simply make one up for the engine to camera.
the timing light can be simply made to stay switch on by simple electrical tape around the trigger.

its not hard to set it up as long as i dont it to look pretty ha ha
then i would simply put the camera into video mode and see the results from the strobe of the timing light.

i think video would be far more realistic to try and get than a static photograph at the exact right time of spark.

my set up will be something out ofmad max, just strong and do the job its meant to just the one day.

i do make some wierd crap at times from all sorts of junk, i do sometimes make some very good bits as well.

your on the right track with the camera thing though,but i would use video.



phill

 

[clanton]

Re: Timing at full throttle on the boat ??

Now I could go for this. This project could go with the electric fuel pump project I never finished.

 

[MaPaHa]

Re: Timing at full throttle on the boat ??

My brother and I used to each have a '70's model straight 6 Mercury 115 HP. I set the WOT timing on them with the boat strapped to the trailer backed into the water but I strapped wood blocks to the trailer so the foot of the motor would push against the blocks and not put as much stress on the back of the boat. I suppose you could re-adjust the transom saver to do the same thing. I used as many blocks as needed to get the motor in a normal upright position based on the angle of the ramp. This was years ago and I used the regular prop. Today I would find a low pitch prop that would not overload the motor and let it rev on up instead of lugging at 4,000 or so RPM.

BTW, I really like the method mentioned in this thread and I know a lot of R & D went into it. I've got two motors I'm going to do a link and sync on this winter and I'll certainly do that first and then maybe check it in action.