1967 evinrude 33hp ski twin, spark plug cross reference

[gintstone]

I have the manual in pfd form, and it says that the plugs that are acceptable is the champion J4J, Autolite A21X, or AC Delco M42K. I ende up asking for the Champion J4J's they didn't have them so they cross referenced a and got a Autolite 353??? I cross referenced the J4J's online and it gives me Autolite 313's, hmmmmmm. When I cross reference the M42K's it tells me I can use autolite 303's, 313's, or 353?!?!?! what the fack. So what one is closes to a J4J, A21X or M42K. I thought there would only be one of each brand that is cross referenced with the plugs the manual recommends. Any suggestions on which plug I should use. I know the different numbers are how hot the plug is, but what I don't understand is why they gimmie 3 or 4 different heat ranges for a cross reference of the "proper plug" that the manual suggests. thx guys.

 

[Daviet]

Re: 1967 evinrude 33hp ski twin, spark plug cross reference

You woun't find any J4J's anymore, they changed to J4C. If you are going to do much low speed operating, I would use J6C's.
In fact I use the J6C's for all of my engines, don't foul as easy.
I would stick with the champion plugs, the engine was designed to use them.

 

[kfa4303]

Re: 1967 evinrude 33hp ski twin, spark plug cross reference

+1. Champion J6C is the way to go.

 

[lindy46]

Re: 1967 evinrude 33hp ski twin, spark plug cross reference

+2 - use J6C

 

[kbait]

Re: 1967 evinrude 33hp ski twin, spark plug cross reference

+3.. J6C.

NGK B6S are fine too. I buy whatever's cheaper and have had no issues w/either brand.

Both are usually under-gapped from the factory, so have your .030" gauge ready.. Some folks gap 'em wider for lots of low speed trolling, but I've never had a fouling issue at .030" with these plugs.

 

[gintstone]

Re: 1967 evinrude 33hp ski twin, spark plug cross reference

K thx guys j6c is what im gonna run

 

[gintstone]

Re: 1967 evinrude 33hp ski twin, spark plug cross reference

I forgot to mention i run my 33hp skitwin at 32-1 ratio. Still use j6c?

 

[Daviet]

Re: 1967 evinrude 33hp ski twin, spark plug cross reference

Yep, the J6C's will work fine.

 

[kfa4303]

Re: 1967 evinrude 33hp ski twin, spark plug cross reference

yeah. I think you can run 50:1, technically, but I run 24:1 in my old motors. 32:1 is a nice compromise. The plugs will be fine either way.
Here are some handy links.

http://www.marineengine.com/parts/v...ntage-evinrude-johnson/382089/38208900001.htm

http://www.duckworksmagazine.com/04/s/columns/max/24/index.cfm

 

[gintstone]

Re: 1967 evinrude 33hp ski twin, spark plug cross reference

now I just need my skitwin to gey my 1970 mfg 16' up on plane (anyone know how much my boat might weigh?), previous owner decided to paint the entire outside of the boat in house paint, and I think that's hampering the boat planing :/ Maybe a hydrofoil will help? Anyone got a used hydrofoil for sale, lemme know. I don't know what they were thinking. The paint feels grippy to the touch, so why would they think it's going to cut through the water without much friction. Anyways, after the maiden voyage we notice the paint was peeing off the hull, so now, when me and my buddy are goin fast in the boat, we say we're "Peelin' Paint." Also adopted that as the boat official name, hehe. Only paid $400 for boat, motor, and trailer.

 

[kfa4303]

Re: 1967 evinrude 33hp ski twin, spark plug cross reference

I like the black on black, but I bet it gets hot. No telling what the previous owner used to paint the boat. Best to strip it off and start fresh, if at all possible. However, the paint won't keep you from getting on plane. The motor should be strong enough, if it's running correctly. You should probably get up to around 25 mph with 1-2 people. Hydrofoils are kind of a gimmick and you shouldn't nee one if your motor is trimmed properly. You want the anti-vent plate, found just above the prop, to level, or slightly higher than the keel of the boat. Most folks usually use the 2nd or 3rd pin setting away from the transom. Trimming the motor "out" (i.e. away from the transom) should make the bow go down and vise versa. You can also try moving the fuel tank and/or battery around in the boat to redistribute the weight. Here are some vids of folks in similar set up so you'll have an idea of what to expect.

http://www.youtube.com/watch?v=LPQhuVhkLtU
http://www.youtube.com/watch?v=lr4ZyXMolag&feature=related
http://www.youtube.com/watch?v=1z3M2z06I5I&feature=related

 

[gintstone]

Re: 1967 evinrude 33hp ski twin, spark plug cross reference

ty very good info, and your just about right, 20mph last time we took it out, it did feel sluggish tho, I need a marine tach to tell what RPM's my motor is turning at WOT. I'm aiming tward the pitch of my prop causing my planing issues then, if you don't think the house paint is doing it. You know what. I am a doofus! I just thought about it, I am trimming my motor in (tward the transom) to try to help out with planing, the nose of the boat will be too high, I'm trimming it backwards aren't I?

 

[Daviet]

Re: 1967 evinrude 33hp ski twin, spark plug cross reference

If you trim the lower unit towards the transom, it will try and push the bow down, into the water.
If you trim the lower unit away from the transom, it will try and push the bow up, out of the water.

 

[gintstone]

Re: 1967 evinrude 33hp ski twin, spark plug cross reference

alright I was going the right way with the trim, I should have mentioned that my buddy riding with me weighs 300lbs, hahah no wonder we had planing problems. The boat itself is only rated for 600lbs, and can hold up to a 50hp, I wanna get a 60, think the 'ol MFG can hold that kinda weight? Anyways, I did run the boat today with a slightly lighter friend (160lbs) and we planed out nice and ran great on the same trim setting. Felt like we were doing about 22-23mph, although I couldn't tell for sure, I didn't have my phone to use the gps. Hmmm, wonder what prop is on there, the numbers should be stamped on one of the blades right?

 

[yorab]

Re: 1967 evinrude 33hp ski twin, spark plug cross reference

Take your rig to a landfill, scrapyard, feed store, or anywhere that has a truck scale. If they aren't busy, ask if you can weigh your rig unhitched. You can look up the weight of you motor and you can estimate the weight of your trailer. This'll give a ballpark weight of your boat.

 

[gintstone]

Re: 1967 evinrude 33hp ski twin, spark plug cross reference

good idea thx

 

[Chris1956]

Re: 1967 evinrude 33hp ski twin, spark plug cross reference

That motor is about 140#. That boat should be no more than 400#. It should plane easily with that motor, and give 20+ MPH performance.

Take a compression test and a spark test. That motor should be run at 50::1, since it is newer than 1964.