johnson 15 horse hole in piston

[mike lewis8]

help i went to change plugs after a weekend of use and found a small hole in lower piston the motor ran fine but developed a small miss the last day so that is why i figured plugs need to be changed is this normal i just never noticed it before, it is a 1980 johnson 15 horse 2 cylinder johnson 15 horse

 

[rwise]

Re: johnson 15 horse hole in piston

Welcome to Iboats!<br />no it is not normal for the piston to have a hole through it. can be caused by an air leak on the engine side of the carb or plugs that are to hot.<br />Ricahrd

 

[mike lewis8]

Re: johnson 15 horse hole in piston

hey thanks for the input but i may mention that it is not the whloe way thru from what i can tell the plugs have been the same for 25 years from a dealer close by , what do you mean air hole ? and do i have a big problem ? thank you

 

[mike lewis8]

Re: johnson 15 horse hole in piston

this motor is or was in excellent shape including paint , i am willing to fix it as it was my fathers

 

[lark2004]

Re: johnson 15 horse hole in piston

can you post a picture, or a link to one, of this hole?

 

[Solittle]

Re: johnson 15 horse hole in piston

Please do not post the same question/problem twice.

 

[OBJ]

Re: johnson 15 horse hole in piston

Well, realtree....you either do or don't have a hole in the piston. Your previous post stated that both cylinders compression was 95psi. And one of the guys said if it was a hole it would be flat zero. Soooo....which is it? Are you sure it's just maybe a little burned place or maybe carbon that looks like a hole. And as SoLittle posted, please keep your post together when dealing with one problem. Makes it hard to keep the help going in one direction.<br /><br />Thanks.

 

[mike lewis8]

Re: johnson 15 horse hole in piston

thank you i am new here sorry for more than one posting di not mean to cause any harm

 

[OBJ]

Re: johnson 15 horse hole in piston

No harm done Michael. Happens on occasion. What we need to know is, was the compression test true....ie...done a couple times to verify the compression? Are you sure it's a hole or as I posted before, something that looks like a hole? <br /><br />Does the engine still run good? The 9.9/15's are tough little engines and will take a lot. Any freaky things with the engine lately? (can't spell anomaly, anomely....something like that.....