Splitfire spark plugs in boat motors?

I just bought a set of Splitfire spark plugs for my Volvo sterndrive.
Has anybody used these plugs in their boat motor?
How well do they perform? I'm wondering what to expect.

Re: Splitfire spark plugs in boat motors?

Expect nothing. The split in the electrode really does nothing for the spark and is just a marketing gimmick. I regard them about the same as those "turbo plates" you put under the carb to "increase atomization" and give a "miracle increase in horsepower"--a fool and his money are easily parted.

At least with Split Fire, you are getting a functioning plug for about the same price as other brands though.

Only time you might see an improvement is when or if you have fouled plugs. Then the split by offering two alternate sites for the spark to jump to MAY have an advantage. Currently, if your engine runs well, you will not see any more horsepower or speed.

Just my opinion and I'm sure others will beg to differ. But consider: if they really did give an increase in horsepower and thus gas mileage, don't you think detroit would put them in all their cars to help meet govt. mileage mandates?

Re: Splitfire spark plugs in boat motors?

run the plugs the engine manufacturer recommends.

Re: Splitfire spark plugs in boat motors?

Ayuh,......... Frank's Right...........

Yu don't say What your motor is,... Chevy or Ford,......
But,......
If it's a Chevy based,.....
You can't beat the plain ole AC MR43T, or the longer 1s for the Vortec heads......

Re: Splitfire spark plugs in boat motors?

That longer one for the Vortec heads would be the MR43LTS. If you got a good deal on the Split Fires you didn't waste any money.

Re: Splitfire spark plugs in boat motors?

I tried them one time in a 1989 Johnson 90. I didn't see a lick of difference. I went right back to the recommended Champ's.

I/O's. As far as I'm concerned: AC for GM's, Motorcraft (not Autolite) for Fords and Mopar for Chryslers.

Re: Splitfire spark plugs in boat motors?

My guess (by looking at your profile) is you have an AQ125 Volvo 4 cylinder engine. NOT 125 hp.
Use the proper spark plugs, and do a tuneup including points, condenser, cap and rotor. Along with setting the point dwell and the timing and you will have a good running engine. Forget the snakeoil plugs.
Oh, and check that timing belt. If it's worn out, all the rest of the stuff will be useless.

Re: Splitfire spark plugs in boat motors?

I used to do all that basic tune up work over 20 years ago.
About 17 years ago I gave my timing light to a relative, thinking that I
would never need one again. I just bought a new timing light to time
the AQ131A VP engine this spring. That is, if I can relearn the process.

Don't worry, I'm not asking for instructions on how to set the timing, etc.
I bought a SELOC manual, and will work my way through the process.
I already bought the split-tongue plugs, so I'll see how they work.
The motor does run fine, and with unbelievable good gas mileage.
I wonder why they don't make it any longer.
Thanks for the tips.

Re: Splitfire spark plugs in boat motors?

Mick,

Don't be bashful about asking the questions. Just do it in the I/O section. There are some great guys there to help you.

Good luck with the Volvo. They were a good package.

Re: Splitfire spark plugs in boat motors?

I've used them before when they first came out, I wasn't happy! Tried them in my 88' Monte Carlo SS 305HO, they gave a minor boost in performance, but the car started pinging a bit, (and this was with 89 octane, a bit higher then required) and I think once in awhile when I shut the engine off, it appeared to want to run on, it also seemed to run hotter then stock just because of these plugs, not good!

At the time, if you examined them, they had a body way bigger then my O.E. stock plugs, sort of a hot plug design, apparently they had very few part numbers, for many different vehicle applications, sort of a universal fit design. I didn't like the concept, and I also noticed they held a lot of heat long after the engine was off. I didn't even have them long enough for the 30 day money back gaurantee, I didn't want to do any more damage to my engine, back in went the stock plugs, returned the Splitfires, got my money back, and I was relieved.

My best advice to you is to use your stock O.E. plugs, if you want to try different brands, to experiment, that's fine as long as they're cross referenced conventional design. IMO, a good set of metallic spiral core suppression wires, will be a better, more dependable, choice, that will give you just as much power, or more, then the Splitfires. Good Luck, Mike

Re: Splitfire spark plugs in boat motors?

When in doubt about any sparkplug give them the dockside float test.

Procedure:
You must be in the water at dockside.
Very gently lay the plug on the surface of the water and release it.
If it sinks replace it.