1987 4 Deluxe QL77jc4 or '86's

[songdog]

I have 1987 Deluxe 4 E4RDHCUD- B1382644<br /><br /> The plug charts I've refrenced do not show a deluxe model 4 in 1987. She currently runs the '77JC4's and I'm noticing some significant carbon build up. The motor is used for trolling and on occation powers a small near shore skiff at near WOT. Can some one please clarify the plug.<br /> I run 87 octane mixed 75:1 with XD50.

 

[angus63]

Re: 1987 4 Deluxe QL77jc4 or '86's

Your motor calls for QL86C or L86C champions gapped at 0.030". Also your motor is a 50:1 motor even though you use XD50.

 

[angus63]

Re: 1987 4 Deluxe QL77jc4 or '86's

I believe the 77 burn cooler than 86 plugs, which would explain the build up.

 

[songdog]

Re: 1987 4 Deluxe QL77jc4 or '86's

thanx angus that is the way I was leaning. The nominclature on the motor says 100:1 now I did learn from the I-Boats resident experts that this was an attempt to reduce emisions but the mixture lacked corrosion protection. I went strait to 50:1 then the build up occured so I leaned her back to 75:1 in an attempt to offset the "cooler plug". Long story short, thank you.

 

[Cricket Too]

Re: 1987 4 Deluxe QL77jc4 or '86's

Your best bet would be to run the 86 plugs gapped to .040 if you troll a lot. I'd probably richen up to 50:1 if you are gonna do any WOT runs, but I guess the 75:1 would be alright for mostly trolling.

 

[papasage]

Re: 1987 4 Deluxe QL77jc4 or '86's

ther was a revision on the 100:1 on some in that year range. i would run 50:1 all the time just dont idle a lot.or less oil and idle all the time . you can chack with a dealer that was in buisness at around that time would know. my soninlaw x now has a 48 hp and it went south and had to rebuild it . now it is 50:1 mox