Hot rod V4s

[Freddie Webb]

The Yamaha flywheel has to be cut to the omc crankshaft taper. You will need a Yamaha to omc bearing cap, you can machine and weld to two together or you can buy them aftermarket. The year of Yamaha ignition you are looking for is 1986-1989. Powerabout, you should try the Yamaha ignition on one of your engines and test it for yourself. I have done it on a v4 and a v6. I also like the msd ignition although it doesn't have a charging system unless you run an alternator, but I am working on that.

[upyours]

yea what Freddie said

[floatbote]

electromotive has some very good stuff that can be used on a outboard,need to remove magnets on flywheel and machine for a 58 tooth trigger wheel,way accurate and very programmable can even do efi if you want to spend $.their xdi boxes are ignition only and cheaper.

[71V153]

electromotive has some very good stuff that can be used on a outboard,need to remove magnets on flywheel and machine for a 58 tooth trigger wheel,way accurate and very programmable can even do efi if you want to spend $.their xdi boxes are ignition only and cheaper.

I'se just a po Floda boy ...

[powerabout]

The Yamaha flywheel has to be cut to the omc crankshaft taper. You will need a Yamaha to omc bearing cap, you can machine and weld to two together or you can buy them aftermarket. The year of Yamaha ignition you are looking for is 1986-1989. Powerabout, you should try the Yamaha ignition on one of your engines and test it for yourself. I have done it on a v4 and a v6. I also like the msd ignition although it doesn't have a charging system unless you run an alternator, but I am working on that.

it was about flywheel and stator only hence my question.
I reckon for under 8000 I would go inductive, pull the charge coils off the stator and keep all that stock less your new pickup system?

[olboatman]

Can someone help out an old man and explain the bennies of programmable ignition ..... would retarding at wot be one? This has always interested me and I see there are some well informed on this thread!
Thanks
Gary

[powerabout]

does the yam ignition advance or retard at wot?

[71V153]

Fwiw I got the 'stock' CDI stuff on my latest xflow. A la unlimited power pack. At 7400 or so she sparks just fine.

[olboatman]

Fwiw I got the 'stock' CDI stuff on my latest xflow. A la unlimited power pack. At 7400 or so she sparks just fine.

Thats what I've been told!
Gary

[powerabout]

the secret to OMC ignition is the charge coil voltage.
OMC race engines used to have blue stators as they put out lots.

[olboatman]

the secret to OMC ignition is the charge coil voltage.
OMC race engines used to have blue stators as they put out lots.

power is there a part # for that stator....or is it NLA.
Gary

[powerabout]

just looked, cant find it written down but its stamped on the stator, I will post it when I next can
I'll bet its NLA
CDI made a special for the sst100 with 4 charge coils, that should work

[Umassot50]

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.

[powerabout]

You can glue a magnets to the undersideof flywheel for your pickup.
Lots have done that.
Or make a large diameter wheel and screw it to the underside close to the ringgear.

[Freddie Webb]

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��