which plugs for my '65 40 hp?

[dafox99]

The plugs in it are NGK ... I seem to remember L77J4 Champion as the right one? not sure they even make those anymore. Also .. anyone know the gap? The motor runs fine through the ignition timing advance, but that last 1/3 of throttle when just the throttle plate is moving, it either sort of bogs or surges a little, but no extra power. Clogged high speed jet? When I pull the cap screw at the bottom of the bowl over the high speed, gas runs out.<br /><br />One more odd thing. I just bought this .. changed the lower unit lube (put in new plug seals) and when I pulled the plugs to check the oil, it seemed emulsified. I put the lower plug back in, put the lower unit in a bucket of water, and was able to put about 20 - 30 psi on the upper plug. No bubbles, and it seemed to hold the pressure just fine. thoughts?

 

[Scotty's Fujiboat]

Re: which plugs for my '65 40 hp?

Do you have a make & a model # for your 65 40HP?<br />Im pretty sure that the gap for those plugs is .040 for a 50 HP<br /><br />As for the lower, Im not sure what to make of that

 

[dafox99]

Re: which plugs for my '65 40 hp?

Oops .. forgot that piece of data. Model number is RKL-27A

 

[Goodoleboy]

Re: which plugs for my '65 40 hp?

Hi Dave!<br /><br />When you drained the old oil from lower unit, was it also milky.<br /><br />If it was, it just may be that some of the old oil did not commpletly drain. Their fore it has contiminated the new oil, makeing it apear the unit is still leaking. <br /><br />As you have said it holds air presure, I doubt that its takeing in water.<br /><br /> I have used diesel fuel to wash out a lower unit that was leaking water, just fill it, then put in gear at idel speed for just a minute, drain and refil with new oil and new o ring seals on both screws. Good Luck!

 

[dafox99]

Re: which plugs for my '65 40 hp?

Thanks, pal. I think you may be right. I'll flush with some diesel, and refill.

 

[SpokaneBassPro]

Re: which plugs for my '65 40 hp?

Champion plugs are J4J. NGK is B7S. and Autolite is 353. Torque to 17 ft lbs.

 

[itstippy]

Re: which plugs for my '65 40 hp?

Don't put 30psi into the lower for an air bleed test. Not even brand new seals are designed to handle that; you risk blowing the seals you're trying to test. 8psi tops.

 

[lark2004]

Re: which plugs for my '65 40 hp?

the engine was designed for the Champion plugs, use them. The NGK will give you pre-ignition due to to the electrode design, it gets hotter than the champion.<br /><br />the manual calls for AC-M42K, or Champion J4J gapped at .030"<br /><br />You should also do a vacumme test on the lower unit as well as the pressure test the vacumme test should hold about 6 - 10 psi, and the pressure test 15 - 16 psi (as written in the factory manual)