Iridium Plugs in my 225?

Hi all, this group has not steered me wrong through a very thorough rebuild of my entire ignition system last year. Still running great, always looking for improvements. I am hoping for some advice.

1987 Evinrude 225. It has newer marine Champion plugs in it, model QL77JC4. I got advice from a motorhead a couple of boats ago that iridium plugs would cure my cold-start fouling blues and improve performance. For my 1977 Johnson 70 hp, he was right! It ran like a top and my fouling/flooding problems vanished. Mileage improved.

Can I use the NGK BR8HIX plugs left over from this purchase? I still have eight of them in the box, and the measurement specs are identical, but I dont want to risk misfiring or other ignition wierdness without the inductive resistors that the Champion QL's have in them. Will I get radio problems? Will my engine run hotter, more efficiently, both? Neither?

Thanks in advance for any help.

Dan

Re: Iridium Plugs in my 225?

Be very careful when running plugs other than Champions in a carb'd OMC. You can run any plug you want but just make sure the motor is jetted right. Some plugs that "cross" to Champions will actually burn hotter. OMC carb'd motors are calibrated for Champions and 87 octane at a given timing spec. Any time you deviate from those paramiters you need to check and make sure it's not too lean.

Re: Iridium Plugs in my 225?

Thanks very much. I figure that as long as I am not overheating it should be okay, eh?

Given the fact that my fuel pump is a VRO, is there a way to fatten up the mixture and stay on the safe side? I could always add some oil to the fuel tank, but don't want to overdo it.

Re: Iridium Plugs in my 225?

We're not talking about engine coolant temps but rather combustion temps. It's possible to have very cool water temp and still burn a piston.

The fuel / oil pump has nothing to do with the fuel / air mix. That's all done in the carbs and throttle bodies with jetting and components.

Re: Iridium Plugs in my 225?

not worth it

Re: Iridium Plugs in my 225?

Okay, thanks. Easy does it I guess- What I don't understand is how or where I can make adjustments to any of this. (Carbeuration) I have completely rebuilt everything (and I mean everything) in this motor that has to do with fuel or ignition, and in truth, it runs great.

However, once in a while, unless I start it "just so," I get flooding and no start until I remove the plugs, blow on them etc. This problem went away with the iridium wire plugs on my old 1977 70 hp Johnson (which is why I asked to begin with), but as this is a much bigger monster, I am taking any approaches to souping it up pretty carefully. when I got the thing, it wouldnt spin more than 3000 RPMs. now I can run 5700 all day, but again, once in a while, I get bitten in the tail by this startup hassle with the fouly plugs. maybe I need to lean it up a bit. (i.e. use a hotter plug?)

my sealoc does not provide any instructions for air/fuel mixture adjustments or carbeuration. as far as I know, its all done by the VRO and the hi and lo speed jet orifices. are these tune-able? is this out of the realm of the do-it-yourselfer?

Re: Iridium Plugs in my 225?

The VRO only mixes fuel and oil. It has nothing to do with calibrating the fuel air mix. That's all done in the carb assemblies. The low and mid range jets are air bleeds and are removable. Which I'm sure you did when you cleaned the carbs. The high speed jets are fuel jets and removable. Again, I'm sure you did that when you did the carbs.

Describe your starting proceedure. That has a lot to do with the problem you describe. I have basically the same motor but newer (1990) and here's what I do;

1- Pump the fuel bulb. That puts fuel pressure in the lines.

2- Turn the key to the "On" position. DO NOT engage the starter.

3- Push the key in for an 8 count. This opens the primer solenoid and allows fuel under pressure into the intake behind the carbs. It also limits the ammount of fuel going in by the line pressure. You can hold that key in (primer on) all day but unless the line pressure is renewed, by either pumping the bulb or the fuel pump when the motor is running, only so much fuel will enter. And that's not enough to flood it.

4- Turn the key to the "Start" position. The motor should start almost instantly.

As it warms up you may have to bump the primer a couple of times but if the T-stats are working correctly it'll warm up in a minute or so.

You don't have the Quick Start feature which automatically raises the rpm's so you'll need to give it some throttle before you try to start it. Once it starts let it warm up at 1200 to 1400 rpm or so. You'll get a feel for it quickly.

Now, all this is assuming that everything is working as it should. Ignition, fuel delivery etc.

Re: Iridium Plugs in my 225?

I believe that everything is working properly. it used to be that the thing would only start when it was cold. then after running a while, I could cut the engine and five minutes later, flooded no start. so I rebuilt all the carbs (two were mungey, stuck open and letting in fuel when the motor was hot) and the problem went away. you were the one who diagnosed my "hot percolation" problem actually. however, I guess I just need to refine my starting procedure. one thing that bums me out a little is that there is no way to goose the throttle without putting it in gear. so I goose the primer during warmup, which works well, as you describe.

Is the Quick Start feature an aftermarket add-on that I can install? I havent heard of this, will look it up.

Thanks, DHadley. You the man.

Re: Iridium Plugs in my 225?

My boat did the same thing. It started perfectly fine cold and then I ran it around the lake until I found a really good fishing spot. We stayed there about 30 minutes and then the engine wouldn't start properly. So we let the starter cool down for 2 minutes after every start and then it started ok, thought it was odd that it started cold just fine but then wouldn't start after it was ran for a while. You said that the carbs get stuck open, thus letting in fuel?? So I would you recommend that I rebuild the carbs if this happens again? The remedy for a flooded engine is just to let it sit right, so that the fuel will evaporate?

Re: Iridium Plugs in my 225?

Beach, there will be a way to advance the throttle without it going in gear, depending on which control you have. If it's a side mount or top mount, pull the handle out when in neutral. Then advance it.

If you have another type, let us know what it is. There's always a way. I think you just solved your hard start issue.