rebuilt power head , idles rough

[sam03v]

Hello,

I recently rebuilt the power head on my 35hp 1978 johnson, new pistons, bearings, fuel pump, the works. First time I've ever attempted a rebuild. I fired it up yesterday for the first time, I had a garden hose connected to the lower unit using those clamp on things. I didn't run it for long since I need to break it in on the water, but I wanted to make sure it would start. It did, but it idled rough. Should I be worried about this or is it normal for a rebuild to run rough initially. The fuel tank is old and has a leak around the fuel level indicator if I tip the tank at an angle(with it full). The fuel bulb stayed primed so I'm guessing the leak is not a problem. I haven't messed with it too much yet since it was late last night when I got it going. Any suggestions or comments on breaking it in or on this idle issue would be appreciated.

Thanks in advance,
Sam

 

[wilde1j]

Re: rebuilt power head , idles rough

Did you do a link and sync?

 

[sam03v]

Re: rebuilt power head , idles rough

No, I didn't. How would that affect the motor..good or bad..?

 

[JB]

Re: rebuilt power head , idles rough

Please do not double post, Sam. This is a message board, not a chatroom.

You need a Service manual. The link 'n'synch is critical to proper performance.

 

[sam03v]

Re: rebuilt power head , idles rough

Sorry, the double post was an accident.

I do have a service manual, but sometimes advice by folks like you is more useful than the book..so you got any advice besides read the book?

 

[Mark42]

Re: rebuilt power head , idles rough

The Synch and Link will ensure that the timing advance is set properly for the throttle possition. Also ensures that carb linkage is proper so that the butterflys are not "over" opening or not fully opening and are synchronized with each other. Also full throttle stops are set right, etc.

Yep, that has something to do with how it runs and idles.