jonson 9.9

[Natebreck]

Hey everyone quick question I have what I think is a 70s Jonson 9.9 sea hores and it needs a ring job would anyone know if it’s worth fixing a motor of that age

 

[racerone]

It is if you do it yourself.----But what is your motor doing / not doing ?----What trouble shooting have you done if any.-----Just putting rings in possibly worn grooves might be a mistake too.

 

[F_R]

What is the exact year of your 9.9? I certainly wouldn't spend that kind of money on a 1974-1976. Are you assuming it needs rings because it fouls plugs? Those years did that when new right out of the box.

 

[Natebreck]

It doesn’t have full comprehension and and only has half the speed that it use to any ideas ?

 

[Natebreck]

And it’s getting harder to start

 

[flyingscott]

What is your compressio? Those motors run fine 90#s of compression. Running at 1/2 speed sounds like running on one cylinder.

 

[racerone]

Post a model # of post some pictures of the engine and powerhead.----No need to ASSUME it needs rings.-----Could be a blown head gasket . ----Some inspection on your part needs to be done.----Post your actual compression numbers.-----Statements like " good compression "----Or ---" it doesn't have full comprehension " ---just mean nothing to folks ( 1050 miles away ) trying to help you !!!

 

[F_R]

Probably running on one cylinder. Did I mention they fouled plugs?

 

[Natebreck]

Thanks yeah the compression test had low numbers in one and I wish I could send pictures I’ll have to send them at another time the motor is in upstate ny about 350 miles away

 

[Natebreck]

I tried the plugs last year and it didn’t change

 

[oldboat1]

might want to wait for those pictures. Current info. is that there is a European mutation of Covid 19 here in NY.

 

[Natebreck]

Another quick question would a car battery Work to start a 30 horse motor or do I need a boat battery

 

[oldboat1]

Car battery will work. (Better if you plan to keep it charged/topped off, otherwise deep cycle a better choice.)

 

[racerone]

Even a garden tractor battery would work fine for a 30 HP motor.

 

[Natebreck]

Thanks guys