100 to 1 oil mixture? really???

[dfrants]

just picked up a 1985 6hp Johnson that won't idle, the plugs turn wet and black. on the side of the cowl there is a 100/1 oil mix decal???? really? is this recommended still? i thought 50 to 1 was the norm. could this be the reason the plugs turn black and won't idle?

 

[Joe Reeves]

Re: 100 to 1 oil mixture? really???

50/1 in still the norm..... 100/1 was a OMC goof that resulted in quite a few blown powerheads.

Weak Spark?

 

[F_R]

Re: 100 to 1 oil mixture? really???

Do not use 100:1. That was a big mistake by OMC. They sent out a bulletin telling to use 50:1 and remove that sticker. So, is that the cause of your problem? I don't know, it might be if your motor has been damaged by running 100:1. First things first, check your compression.

 

[nwcove]

Re: 100 to 1 oil mixture? really???

as mentioned 100:1 is a no go ! i would start by checking the t-stat for proper operation. i have a slightly older 4.5 that has never been ran at 100:1, just a guess on hrs....must be 500....95% of that runtime was slow trolling, and it still has the original plugs. if your t-stat is still there and works, you may want to consider a slightly hotter plug ? i think that motor came with ql77jc4, maybe go to a ql77jc6. ( dont go by those numbers tho, confirm it! as i am going by memory, and memory nowadays is gettin a bit foggy! lol)

 

[dfrants]

Re: 100 to 1 oil mixture? really???

checked the compression, 105 top, 100 bottom.