74 and 88 johnnyrude 15hp dies at low idle. im going crazy!

i have successfully taken motors from the grave to running except for these three motors. i am getting flustered to no end. i hope someone can give a little advice?

three motors, all dont low idle. same symptoms. at low idle they die.

88, evinrude, 15 hp. new hoses, rebuilt carb used all the pieces in the kit, rebuilt fuel pump, compression is 125 in each cylinder. i still need to replace the plastic carb cover to see if this changes the low idle issue. replaced the switch box as well. runs really well from off idle (where u line up the shift arrow) to wot. lots of power full spark and fuel.

74, johnson, 15 hp. new hoses, rebuilt carb used all the pieces in the kit, rebuilt fuel pump, compression is 120/115 in each cylinder. this has points and am waiting for new set of points. i filed the old points and cleaned them with electrical cleaner and finished off with some clean paper. only barrel tested this one. i have spark, and fuel and compression

74, mercury 7.5hp. new hoses, rebuilt carb used all the pieces in the kit, rebuilt fuel pump, compression is 130 in each cylinder.

** i have a brand new tank and hose, glass filter so i can see the fuel and there is no bubbles at the fuel tank. **

arrrggghhhhh all start easy, run, just no slow idle.

dino

Re: 74 and 88 johnnyrude 15hp dies at low idle. im going crazy!

can you post movi on youtube how all motors run?

Re: 74 and 88 johnnyrude 15hp dies at low idle. im going crazy!

had same issue with a 15 hp evinrude.turned out to be the coils.look very very closely at them .even a hairline crack can cause you grief.baring that, its strange that all 3 are doing it .do you have the idles set a little low?using the proper plugs?champion for the omc,s ngk for the merc?changed the gas just in case you got a bad batch maybe?

Re: 74 and 88 johnnyrude 15hp dies at low idle. im going crazy!

gas is new. plugs are all new ngk for the merc, champion for the evinrude.

merc has been stored for about 20+years and is good overall condition.

88 evi is from the same owner, both motors were stored covered in a garage. this motor has low hours it is in almost mint condition even the clamp is in mint condition.

74 is a little trashed. i got this with the tinny i just bought. dont know much about this one.

i will post some pictures later today.

the coils seem to be ok. thanks for the tip though. i guess i better check the coils.

dino

Re: 74 and 88 johnnyrude 15hp dies at low idle. im going crazy!

raczekp1 said:

can you post movi on youtube how all motors run?

Click to expand...

i can video at least one of the motors tonight. will get the others posted in a bit. have to go to work and will be back later.
dino

Re: 74 and 88 johnnyrude 15hp dies at low idle. im going crazy!

Did you set the rich/lean carb adjust properly when you cleaned the carb. The initial settings of 1.5 turns out from seated is just to get it started and warmed up. It will run rough at that level and may require a higher idle.

Re: 74 and 88 johnnyrude 15hp dies at low idle. im going crazy!

OptsyEagle said:

Did you set the rich/lean carb adjust properly when you cleaned the carb. The initial settings of 1.5 turns out from seated is just to get it started and warmed up. It will run rough at that level and may require a higher idle.

Click to expand...

yes i adjusted the low idle needle.

dino

Re: 74 and 88 johnnyrude 15hp dies at low idle. im going crazy!

here are some picts of the 74

Re: 74 and 88 johnnyrude 15hp dies at low idle. im going crazy!

i wouldnt trust those coils they have the exact same hairline crack mine did .i change mine and my idle and starting issues went away completely.you cant see it but those cracks are proably letting moisture into the inner coil and shorting it out.

Re: 74 and 88 johnnyrude 15hp dies at low idle. im going crazy!

thanks rude! gonna get some coils
here is the video
http://www.youtube.com/watch?v=OlAzbODqZ08&feature=youtu.be

Re: 74 and 88 johnnyrude 15hp dies at low idle. im going crazy!

update, i replaced the carb cover on the 88 now she runs perfect!