'94 E120ETLERC Misfire??? Wrong plugs!!!

jimbobcooter

Petty Officer 3rd Class
Joined
Feb 27, 2012
Messages
78
Hello,
New to the forum and boat ownership. Although I have been around boats my whole life this is my first large outboard boat.

I recently purchased and '94 Evinrude 120. I took it to a local authorized mechanic to an inspection prior to taking my family out. I am mechanically inclined, but prefer to get an expert opinion esp. when the family and water is involved.

Mechanic said if I would have run the enging I could have destroyed it due to improper plugs and a bad power pack. Said the plugs were too long and would have destroyed the pistons (yet had no obvious damage at this time). Also stated that engine was only running on one cylinder.

Does not sound or look that rough to me. Also would it start and run if the pack was bad? How would there be no damage to plugs if they wer 1/2 to 1in too long? AM I GETTING TAKEN? SHOULD I GET A 2ND OPINION?

Videos (If you can not view the video hit the arrow at the bottom to go to video 2of 2 and you should be able to see at least one of the videos)
https://www.dropbox.com/s/3o184xde14..._1818.MOV?dl=0

https://www.dropbox.com/s/7remx1byie..._1810.MOV?dl=0

Additional Info:
Previous owner replaced plugs in 2014 with the same ones that were in there. Although these were the wrong plugs (according to the mechanic) the previous owner stayed he never saw any damage on any plugs.

I think the power pack got fried by previous owner hooking up New battery incorrectly. During the sale he mentioned running a red wire from the engine directly to the battery.

Several good referrals about this mechanic so I am thinking about letting him do the work.

Just worried about potential damage caused by improper plugs. Is there any symptoms/examination techniques that would indicate damaged pistons? Just don't wanna throw good $ on bad!

Compressing checks good!
 

daselbee

Commander
Joined
Jan 20, 2009
Messages
2,765
wow.....running on one cyl. huh?

That engine sounds exactly like it should sound. Runs pretty darn good.
Look up the proper plug number on the many references right here on this site, and see for yourself if they are wrong.

One tip.....why didn't you post the number of the plug that was reported as wrong? Sure would have helped.
Give as much info as you can. Don't let your post leave us with more questions.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,431
What numbers were the " wrong plugs " that were in there?----Pictures of them ?
 

jimbobcooter

Petty Officer 3rd Class
Joined
Feb 27, 2012
Messages
78
Mechanic has boat so I do not have pulg #s. I have heard that engine can sound normal on hose but could still have a bad power pack. Right now I am basically taking the mechanic's word. I did pull one of the plugs prior to taking it to him and it was not damaged in any way.

I have no reason to believe that the mechanic would be dishonest since he is certified and comes highly reccommended by several people. I thought the engine sounded good on the mufs too, but I am new to large 2 stroke engines.


I am only $100 in to the mechanic right now, but power pack and plugs will be like $500!
 

Vic.S

Rear Admiral
Joined
May 4, 2004
Messages
4,719
As above the currently recommended plugs are Champion QL78YC, gapped at 0.030"

However ITYWF that it was originally supplied with QL16V plugs which are surface gap plugs and are what are still shown in the parts lists.

This may have confused your mechanic.
 
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jimbobcooter

Petty Officer 3rd Class
Joined
Feb 27, 2012
Messages
78
Thanks for the clarification on the different part #s Vic S. I do not want to waste my $500 that is why I am trying to get some advice here.

The mechanic stated that they were 4 stroke plugs that were too long (1/2 to 1in) and therefore could have potentially ruined the pistons. However they were run several times by the previous owner w/o being damaged. Would it be possible the 2 different part #s would look that different?

I did not know there was a discernable difference b/w 2-stoke plugs and 4-stroke plugs.

Is it possible that the motor could idol fine with a bad power pack? He stated that it was firing on one cylinder and inconsistent on other 3 cylinders.
 
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jimbobcooter

Petty Officer 3rd Class
Joined
Feb 27, 2012
Messages
78
Ok so I got the boat back from the mechanic and the previous plugs wer NGK ZFR6F replaced with QL78YC. I now have the old plugs and power pack in my possession.

I will be lake testing the boat Friday./

So far happy with the repair except for the fact that my battery was perfect when I dropped off but completely dead when I picked up. Once charged I found the boat radio was left on. Shocking they had to listen to my radio while making repairs and how the hell do you park it in the yard with it still on?

Thanks for all the help. Will post how the lake test goes.
 
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