Timing adjustment

[rc3477]

I have a 1987 125hp force after finally getting the thing setup and running its time for a timing adjustment. The previous owner told me that he had adjusted it as he was at an altitude of 6500 ft. I'm pretty much at sea level. So as it is the first time I've ever done this I've come for advice. I checked tdc and its dead on the mark so I forged ahead per the repair manual. I hooked up the light gun and cranked well I see no numbers or marks just a blinking light. On the wheel all it has is a single line which i assumed to be the tdc mark and then three marks next to each other. Any help would be appreciated.
Thanks
Ray

 

[jerryjerry05]

Re: Timing adjustment

It has to be set running at WOT.Buy a manual.Jerry

 

[rc3477]

Re: Timing adjustment

I have a manual, it says to first set it at cranking with all the plugs out

 

[sweezy722]

Re: Timing adjustment

The fly wheel does still have the timing marks on it doesn't it? Are you putting the timing light to the right spark plug wire? Timing while running can be a little hard and dangerous. I have to agree it is probably the best - however - I time mine at cranking speed.

 

[rc3477]

Re: Timing adjustment

I was trying to do it at cranking, However I couldn't see the marks. I located a bad cd module only letting one of the coils fire and the other one ofcourse #1 cylinder isn't. I'm guessing its firing just not strong as the timing light was still blinking when connected.

 

[jerryjerry05]

Re: Timing adjustment

At cranking speed you need to advance the throttle all the way forward.J

 

[rc3477]

Re: Timing adjustment

Yea thats what I did, I guess I can't time it correctly though if that top cylinder isn't firing. On the lookout for a new module......

 

[rc3477]

Re: Timing adjustment

So I finally got my new cdi box installed and have spark on all cylinders. Hooked up the timing light and I can finally see some marks. Wasn't able to see them before. Well now how do I read these things. The manual says to set it 2 degrees retarded showing a picture of a whole scale on the flywheel. Well I don't have that. My flywheel has a single mark indicating tdc and then a little bit away 3 marks together. Anyone have any idea on this?
Thanks
Ray

 

[sweezy722]

Re: Timing adjustment

The timing should be the same regardless of altitude. The carb jetting changes at altitude is my understanding. As for the timing - Clymer has your engine listed at 30 degrees BTC at wide open running. The 2 degrees retarded (which would be 28 BTC) is referring to checking at cranking speed with the controls fully advanced. It looks like the closest mark to TDC is 28 degrees, the middle 30 degrees, and the farthest 32 degrees. So, if checking at cranking speed you want the first mark of 28. If checking at running wide open you want the middle mark of 30 degrees.

 

[rc3477]

Re: Timing adjustment

Thanks sweezy going to try it out. I'm not sure but I think this may be the cause of my problems. Just above idle around 2500 rpms my engine throttles up and down on its own. More towards top end 5,000 or so rpms it runs pretty decent.