overhauled johnson

[brehlers69]

I over hauled a 25 horse johnson and it runs sluggish. I put .30 larger pistons and rings in it and put it all back together and it just doesnt have that kick it should. Any suggestions would be great.

 

[BoatBuoy]

Re: overhauled johnson

I probably won't be able to answer your question but I will make some suggestions before someone else does. <br /><br />What year/model is the motor? <br /><br />Was it bored? <br /><br />Anything else done to it? <br /><br />Most importantly for the folks here that may be able to answer your question, why were you putting oversize pistons in to begin with?

 

[Dhadley]

Re: overhauled johnson

At .30 it was bored a lot!! We're sure you mean it was bored .030 os but we do need "the rest of the story" as BB mentioned.<br /><br />Carbs cleaned? Right plugs? Fresh gas? Timing right? Sink & link right? Describe in detail what it does or doesnt do that you'd like to change.

 

[brehlers69]

Re: overhauled johnson

I have a 77 johnson 25 horse. Yes i had it bored out .030 because the piston walls were scored. I also had the head plained put all new gaskets in it put over sized pistons and rings in it and had the block plained. carbs cleaned, right plugs, fresh gas, timing right i think, what is sink and link. It runs good out of the water but once i get it under some pull it just climbs to speed very slowly. its on a 14 foot jon and should just fly on it but it doesnt. the plates under the fly wheel were the only things that gave me a little trouble puttting them back on but i have to have them right so what else would it be. any suggestions would be great

 

[Dhadley]

Re: overhauled johnson

First -- you have to be very very careful about cutting the head, let alone the block and head. We gotta keep an eye on that. How far did they cut each (be specific)?<br /><br />Are you sure the carb is clean? Did you soak it? In what?<br /><br />If youre sure the motor is at 100% then it sounds like some set up work may be required. Where is the anti-ventalation plate in relation to the bottom? What prop are you using?<br /><br />I know you say you have the right plugs but which ones are you using?<br /><br />What octane?

 

[Harker]

Re: overhauled johnson

Also, are you still on 25-1 break in fuel? I know my motors are sluggish with too much oil.