merc sport jet 90 w/no spark

[jeremy bwheat]

i'm trying to help a friend with a sport jet 90. the engine will only crank with the black wire w/yellow stripe disconnected. any other time while the wire is connected there is no spark. any help would be greatly appreciated.

 

[B_Eager]

Re: merc sport jet 90 w/no spark

I have the 120 sport jet, they are the same motor except for the displacement. I have a 1999 model and recently purchased the shop manual. The Black and yellow wire is the rev limiter wire. You will have to be very specific on you questions and your wire colors and I may be able to look up your answers, the manual is pretty complete, including trouble shooting.

 

[kenimpzoom]

Re: merc sport jet 90 w/no spark

Where are you disconnecting the black/yellow wire?<br /><br />If at the switchbox (large 2 inch by 4inch box) then it could be the revlimiter or the wire is shorted or the key switch is bad. Revlimiter failures are common on this engine.<br /><br />Check out the links in my sig for more info.<br /><br />Ken

 

[jeremy bwheat]

Re: merc sport jet 90 w/no spark

hey wavehopper. i thank you for replying. the wire in question is the rev limiter wire. do you have the means to send me a wiring diagram? either way thanks for the help, i'll wait to hear from you soon.

 

[alex689]

Re: merc sport jet 90 w/no spark

hey bwheat i've got a 93 jazz with a 90 someone told me to un hook the rev box and if i got spark that was the problem sounds like it might be that for your buddys boat. i disconnected my rev box and got spark took it to the lake to putt out into the middle and now i get spark but only for 5 min or less can anyone think of what might cause this? thanks

 

[Haut Medoc]

Re: merc sport jet 90 w/no spark

This post is 4 years old.......​

 

[alex689]

Re: merc sport jet 90 w/no spark

i noticed that after the fact! kinda new at this site....

 

[Haut Medoc]

Re: merc sport jet 90 w/no spark

Welcome to iboats....​

 

[alex689]

Re: merc sport jet 90 w/no spark

ok enough with font, can you point me in the direction of someone that can help?

 

[Don S]

Re: merc sport jet 90 w/no spark

The engine is a Force outboard powerhead stuck on top of a jet pump.
If the engine has problem, post it in the Force outboard forum.