Speed Problem?

[sfmaster]

hi to all!

I have a 91 johnson/ 90 hp. Starts up great, and starts to run great. Seconds after moving and slowly excelerating the engie kind a jerks and slows down . I then have to press choke and it then picks up speed. But while picking up speed It constantly keeps jerking and I need to keep pressing the choke for it to move. Any idea whats causing it? Im told it could be carb or water seperator? Any help will be appreciated?:redface:

 

[tashasdaddy]

Re: Speed Problem?

less start with the basics, do a compression check, and a spark check on all 4, and report the finds and the compression numbers. we are going to have to do some trouble shooting, to get to the bottom of this one. also change you separator filter, paying close attention for water in the fuel you drain out of the canister.

 

[sfmaster]

Re: Speed Problem?

Okay, I changed the filter and it had water. I noticed the water bubbles it had. I put a new filter in. I installed new spark plugs and Im gonna due compression check today, once my cousin brings me the equipment.

 

[sfmaster]

Re: Speed Problem?

tashasdaddy,

I finally did the compression test, these are the reseluts:

1. Left side pistons = between 90-95 on both.
2. Right side = top - 60
bottom - 65

This is bad right? What I need? it'll need serious repairs?


Thanks!

 

[SKEETR]

Re: Speed Problem?

Do a decarb and test again.

 

[sfmaster]

Re: Speed Problem?

Skeetr,

What u mean by decarb? :redface: sorry for not knowing!

 

[sfmaster]

Re: Speed Problem?

:redface:Never mind, I found out. Im gonna use seafoam tomorrow. Ill post results!

 

[SKEETR]

Re: Speed Problem?

It is always better to try everything you can to ensure that your readings are correct. Make sure when you are testing compression that all the plugs are out so it will spin as fast as possible. Also pull the lanyard or kill switch to ensure the spark is off, for safety as well as protecting the ignition system since the spark is not grounded.

 

[sfmaster]

Re: Speed Problem?

Thanks for the good advice SKEETR

Will do!

 

[tashasdaddy]

Re: Speed Problem?

do the decarb, then retest. if still low, pull the low head, and see if you have a blown head gasket. has the motor ever run hot?