is this good compression

buddylove48

Cadet
Joined
Jun 22, 2008
Messages
26
just had the motor tune up on a 1990 johnson 15 hp.
one has 79 and the other has 80
what is the normal for this motor
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: is this good compression

would like to see it higher, but different gauges read different. is this an electric start or rope. if rope, both plugs removed, and rope briskley pull at least 6 times each. what is good is that they are equal, which is most important. are you having problems?

looked at your other post, how did we get such a change in compression? 120?
 

Benny1963

Lieutenant
Joined
Sep 17, 2006
Messages
1,476
Re: is this good compression

check it again with all plugs out and different gauge ,also may try decarb
but that is low ,
 

iwombat

Captain
Joined
Jul 12, 2006
Messages
3,767
Re: is this good compression

They're even that's good news. It's going to be hit-or-miss on getting to 100psi tugging on a rope. What's making you check compression?
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: is this good compression

you still haven't answered my question, are you having problems. if you don't answer questions, we can't help you. if you are just tinkering, stop, get a manual, before you screw something up, that will take hours, to find out what you did!!!
 

buddylove48

Cadet
Joined
Jun 22, 2008
Messages
26
Re: is this good compression

this is my first boat and i have no way of checking the compression.i wanted to know what the conrols were the knob that turns and pulls out
and when i took it out for the first time. it ran for about 10 mins and i couldn`t get it to restart and then it wouldnt pull the cord wouldn`t pull out. but when i got it home hook up a motor muff it started. but i still took in and got it check, they ran the motor for 45 mins. so i must have done somethan wrong with the controls. i hope i clear things i`am a newbe
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: is this good compression

Some motors you can't pull the rope if it isn't in neutral.
The speed indications on the tiller usually mean little. Just be sure to reduce speed as low as possible before shifting.
To start cold squeeze the primer bulb till firm.With it in neutral advance the throttle till it stops pull the choke or prime as required and pull the rope.it should start in a couple of pulls.when started push in the choke.
When warm; in neutral advance the throttle and pull the rope.
 
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