115 hp Starflite 1973

[Nezlugh]

Found an old set of plugs in boat and kept them for reference. I was having problems with the new NKG plugs being taped by the piston and closing the .040 gap to .025 gap. The old used autolite plugs had double fire rings on them.

Has anyone had the same experience with the QL77JC4 plugs or other brand plugs in this motor 115393 Evinrude?

Why is it happening?

Could someone have installed different pistons or was this engine designed to run on UL77V plugs only.

Put NKG cross for UL77V plugs in and taking it for a run tomorrow.

 

[tx1961whaler]

Re: 115 hp Starflite 1973

Why are you putting NGK plugs in this motor? It was designed to run on Champions.
Champion QL77JC4 gapped at 0.030" is what's called for. If it's not running right with those in there, then there is something else wrong.

 

[Nezlugh]

Re: 115 hp Starflite 1973

Piston is hitting the plug with QL77JC4 or any other plug by any other manufacture. The decal or what is left of it looks like it reads
UL77V. What I can find on a web searching is this is the recommended plug.

I had the plugs in hand at a part supplier to measure the reach and the Champion plugs I special ordered for the QL77JC4 or any other brands available had the same measurments. The Champions UL77V were not available anymore. Even iboats is out of stock on these plugs.

I know from all the searching on iboats the Evinrude forum this motor is supposed to use CHAMPIONS. I would love to use Champion and will if I can get them.

The facts, as I can see them is if there is only 12mm of clearence and when you put in 14mm reach plugs the piston hits them something is wrong.

The question I am asking is - "What could be the problem?"

Why won't the plugs everyone is recommending fit in this motor without the piston hitting the plug?

It, as I see it dosen't matter! The plug type by any manufacture is causing the piston to hit the plug.

Please if you can explain why these QL77JC4's are not working in this motor.

What needs to be done so the QL77JC4's will run this motor without hitting the piston.

As for the resistor type plug, I do not have a fish finder or a radio. Is it possible to have a dependable, functional and operational motor with the flush type plug in a 1973 115 hp Evinrude?

By the way: On the muffs the miss I was getting is not there anymore using the flush plugs. (Not CHAMPION plugs)

Sorry for the ramble!

 

[Nezlugh]

Re: 115 hp Starflite 1973

Took the boat out today with the UL77V equivilent plugs. Hole shot was better than it has ever been, shot across the lake and trolled for about a hour and a half.

After that I could not shift into gear without it dying out. I dug out the old plugs - the QL77JC4 equivilent plugs with the doubled fire rings, gaped the plugs to .040 and was able to fish for the next three hours. I still had to shift into neutral when I hooked a fish and raise the idle on several occasions to clear out the motor sometimes it quit and had to choke to start.

If I can ever get the QL77JC4's I will double ring them to clear the piston and give that a try.

I wish I knew if this has ever been a issue for anyone else out there and what the solution is!

I tried to do a compression check and so far the testers I have tried hit the piston also leaving a mark in the carbon on the piston.

Going to do another decarb to try to remove the remander of the carbon on the piston as I wait to get the CHAMPIONS.

 

[Nezlugh]

Re: 115 hp Starflite 1973

Put the NKG plugs with double fire rings in and went out yesterday. Motor worked just fine. I did notice something while I was trolling the lake. When the motor acted like it was flooding out I reached down to shift into neutral and bumped the choke switch and the motor idled up. The next time it started to idle rough I hit the choke for a few seconds and the the motor evened out and ran for ten minutes before having to repeat.

I live at 6100 feet above sea level is it possible the low idle jets need to be changed?

 

[ezeke]

Re: 115 hp Starflite 1973

You can get the recommended surface gap plugs (Champion UL77V 831M - part # 0384771) Try ishopmarine.com or sea-way.com.

 

[ezeke]

Re: 115 hp Starflite 1973

When a motor speeds up when choked, it indicates that the engine was running lean, or had too little fuel. The problem at high altitude is lack of oxygen, not fuel.