Hot rod V4s

[floatbote]

The reason I was thinking about the Yamaha flywheel is it's steel. I need a steel center tapered hub to attach a small metal pickup trigger plate. Similar to what's already there. The omc is aluminum with a cast in tapered sleeve and it has magnets around the center hub. I guess I could machine off the magnets and screw in a trigger plate ring. I'll look into that. It doesn't even matter which flywheel or charge coils I use. I just need to fit a trigger plate and pickup coils. The system runs on DC so it will run on battery anyway. With stator just charging battery.

To the guy who asked about timing. You want to retard the timing at upper rpm. Coming from a world of snowmobile engine performance I'll say this. A proper ignition advance curve can make a huge difference. Felt in the off idle, holeshot and mid-range torque greatly increased. With the ability to control precisely the timing on the top end to avoid detonation.

The outboards we play with have just about the ****iest ignitions possible. Yes they have a throttle controlled advance mechanism but you can never run more max timing than what is safe for wot peak rpm. Say 19-20 degrees or so.

An electronic cdi ignition changes all that. You could run safely probably 35 degrees or more timing through the lower rpm range to boost torque and get you on plane quicker. The timing curve is electronically rpm controlled. No more throttle advance lever. Probably lock that out or make it a fine adjustment for dialing in the timing.

I can also make the timing curve TPS and rpm controlled. A 3d ignition map. So if you wack the throttle it adds even more timing temporarily then dials it back based on the rpm. This makes for an engine most responsive to throttle input. And would also help holeshot when tps senses the throttle go wot.

Agree totally,the things are so adjustable its crazy.timing has to be so much more accurate with the 60 tooth wheels too.every motor is a little different how it likes to be timed for max power and detonation safety.

[powerabout]

I am not putting the Omc ignition down. The question was asked how to convert to Yamaha. I answered the best I could. Is the Yamaha better? That is why I said try it. Can the Omc turn big rpm? Absolutely! I have turned my f1 v8 9100. My sst100 I have only turned 8200, not saying it won't turn more, not saying that ignition held it to 8200. At the end of the day you have to decide how much you want to spend and is what I'm spending worth what I am trying to accomplish. Is there any performance gained by going to Yamaha from Omc? I haven't seen any gain. Is there any reliability difference going to Yamaha? In my experience I would say yes. I know there are many opinions about this and this is mine take it for what it is worth. Are there benefits to using a trigger wheel and programmable ignition? Yes !! I have seen it on the dyno, but do you really want to spend all that money and time on a programmable ignition that will gain very little? These are all questions you should ask yourself. I also think you should try other options and test it instead of just speak negatively about something you have never even tried, whether it be ignition, compression, or fuel injection. Sorry for the long rant😊

all true but the poster asked about the yam flywheel on aftermarket ignition, hence my question.
One day we might get a dyno back to back on swapping to yam ignition.
My guess the component quality is always better than the OMC so its covers other low output issues day in day out?

[Freddie Webb]

There is no horsepower gain going from Omc to Yamaha ignition.

[FMP]

Stability is a +

[powerabout]

There is no horsepower gain going from Omc to Yamaha ignition.

Does it retard or advance at wot?
can it be programmed?

[FMP]

Strange, had a talk with an aftermarket ign guru. He said no Omc ign ever advanced ahead of the signal. Never, impossible. How do you say it's done?

[powerabout]

There is a reason you need to set OMC timing at rpm but on a merc you can set it at cranking.
They behave opposite.
Put a light on an omc and see for yourself from max advance to max rpm

[FMP]

Set any at cranking and you'll need to add advance to compensate for delay in travel of signal vs high rpm crank speed.

How does the Omc advance it ahead of the trigger signal. Does it do it with rpm reading and leading cylinder trigger, rotation calculations preset to set it off?

[upyours]

my Yamaha ing. pulls timing out at haven't checked it lately best I can remember it was about 2 deg.

[FMP]

The mechanical linkage goes to a full position and stops or backs up a hair at WOT? If it stops full the timing lost is from the crank speed getting ahead.

[gfinch]

Subscribed. Hey Freddie, causing trouble again as usual I see.

[Freddie Webb]

Gary Finch you taught me well��

[Freddie Webb]

Gary Finch call me sometime. I did try to document every detail on every dyno pull on your engine and loved every minute of it. The problem with that is I can't remember anything! Lol the bat cave causes amnesia haha

[gfinch]

Freddie it's CRS(Can't Remember Shix) or my favorite... "I've slept since then".
I talked to "Bat Man" recently, he said the OMC project might restart probably in May...of this year...I'm not holding my breath. LOL.

[Umassot50]

I have no idea what either the omc or Yamaha ignition does to timing after the throttle advance lever goes to max. I believe timing stays constant but due to electrical effects like coil saturation, ect this could vary some.

What I do know is what a proper programmable cdi will do. For example.
Starting timing will be between 5-10 degrees.
You will want this to stay low or same while put puting away from the dock or launch. Same for idle rpm. What's a good idle. I seem to remember 500-800rpm.
So let's say at 1000 rpm when you're starting to give some throttle you ramp up the timing. Maybe up as high as 35 degrees for poor combustion chamber xflow. How quickly you ramp it up will depend on how aggressively you want to launch and build torque. If you need to cruise off plane above idle you wouldn't want to ramp up timing too quick.
So say from 1000 rpm to 2500 rpm you ramp the timing up to 35 degrees.
This is where your launching the boat to get on plane. This is where the extra timing advance is going to help the most. Build more torque and overcome the extra weight your packing in your cooler.
Now the timing will probably stay flat for 1000 rpm or so at 35 degrees. Up to 3500 rpm.
Now your on plane and picking up speed. Now you start to ramp the timing back down(retarding) to a safe level for peak rpm. Say 20 degrees at 7000 rpm. Rpm can vary depending on your engine, how high it can turn. Timing will vary depending on what your engine likes. Depending on the compression ratio, and squish arrangements (for a looper) and fuel.

This all can be changed and tweaked depending on what your engine, boat and driving habbits demand.

So a proper ignition will both advance and retard the ignition timing.

If you add in a TPS. The ignition profile becomes reactive to throttle input making it even more responsive and tunable.