set timing ,1979 rude 140

[boatmoter]

Have a 1979 evinrude 140,fresh motor,new pistons,cylinders bored,before its maiden voyage,would like to set timing and syncro carbs to timing and idle speed,where do I start? all adjustments have been moved and turned,including the stop for the timer base.(was try to get it to idle before I found it had weak compression...)
have timing light,but not sure how to set the timing..

 

[DHPMARINE]

Re: set timing ,1979 rude 140

Maybe someone can walk you thru this,But I wouldn't try it home alone,or at my shop without the OMC manual. Basicaly you find exact TDC on number 1,set the timing pointer to it,and then set your basic timing.From there it is just basic steps,adjusting here and there.

Many OMC products are similar,but vary a bit.That is why I still use the correct manual each time.

Maybe someone has done these V4's enough to help you,but I suggest you call Kencook.com,and get the manual.

DHP

 

[Theoutdoorsman]

Re: set timing ,1979 rude 140

boatmoter.......... Once you find the exact TDC, these are the steps you need to take as per R. Johnson here on the board. It's the easiest way I've seen yet to link and sync this powerhead. I'm sure you'll agree........ I hope you have the OEM Service Manual so as to better understand the terminology discussed in the procedure. If not, pick one up on Ebay and then procede.



Starting from the beginng, these adjustment's can be made easier if you disconnect the throttle cable to get it out of the way. Move in the idle stop screw until the throttle cam is out of contact with the rubber roller, loosen the throttle link screw so that both carb's snap fully closed, then tighten screw. Advance throttle cam until it contact's rubber roller, it should contact top mark, or embossed mark, "same thing" so that it is centered on the roller, loosen screw on roller, and adjust if it is not. This will make the adjustment close enough. Start the engine with the trottle cable still disconnected. With a timing light on #1 cylinder, screw in idle stop screw, and adjust until you are at 4-6 degree's B.T.D.C. Now remove the cotter pin, and washer from the throttle cam yoke, this is the white threaded yoke on the bottom of the cam, remove it from it's pin, and screw it in, or out until top mark, or embossed mark just touch's rubber roller, and replace washer, and cotter pin. Now adjust idle speed to 700, to 800 if running on muff's. Replace throttle cable, and adjust trunnion until the throttle linkage is just back to.the stop screw with slight tension. Shut the engine off, and see if the throttle goes completely open, and back to full idle. This should complete the set-up.


Refer to this link on setting your WOT timing. It will get you really really close if not dead on.

http://forums.iboats.com/bbBoard.cg.../bbBoard.cgi?a=viewthread;fid=28;gtid=1167985

Also, check out my posting mid-way down on that page. There is another link in that thread that will be of considerable use to you in building a spark tester. This will insure you are getting good spark on all cylinders, at the same time, while checking the WOT timing. Works absolutely great!!! And takes about an hour to make it with some old lumber you might have laying around the house or shop.


Good luck................ ALAN

 

[boatmoter]

Re: set timing ,1979 rude 140

Thanks for the info,I'll go thru these steps this week end and I'll let you know if it comes out ok

 

[Theoutdoorsman]

Re: set timing ,1979 rude 140

boatmoter.......... My idle on the hose was somewhere around 1300-1400 rpm's. When submerged in the lake, they dropped to 800 rpm's because of the back pressure when submerged. I liked that range because it made it easier for me to load my boat back on the trailer without it stalling out on me. The service manual suggests no more than 750 rpms, in gear, at an idle though. Just so you know. Your welcome.