76 johnson 9.9

[jag306]

took boat fishing today. motor ran motor would only ran at 1/2 speed at first, then all of sudden it took off, ran good at high speed, but at low speed the rpm's would go up & down all by itself---help

 

[steelespike]

Re: 76 johnson 9.9

Sounds like you have one cylinder cutting out.<br /> You may be able to tell by looking at the plugs.<br />One will probably appear darker and wetter than the other.New plugs may solve the problem if they are more than a season old you need new ones anyway.

 

[sloopy]

Re: 76 johnson 9.9

OH YEAH!!!! <br /><br />You might want to try a Lower burnin plug! it sounds trange but it happened to me!~!! what is the cap on the plugs? and are you ising champian platnum? some of those plugswill fit outboard egines, but they are not made for that!

 

[sloopy]

Re: 76 johnson 9.9

OH YEAH!!!! <br /><br />You might want to try a Lower burnin plug! it sounds trange but it happened to me!~!! what is the cap on the plugs? and are you ising champian platnum? some of those plugswill fit outboard egines, but they are not made for that!

 

[jag306]

Re: 76 johnson 9.9

thanks for the help guys---- i did put new plugs in just before i went out---- gapped at .030 they were denso's (all i could get on the way) could that have anything to do with it? also before i took it out this season it was sitting around for 10 years! i did have a boat mechanic go over it first--new points ,fuel pump, fuel line, gas tank, & lower unit checked----thanks in advance for any help, 76 johnson 9.9