Do I have to adjust timing after replacing broken driveshaft?

[bayprowler]

I just replaced a broken driveshaft on my 1987 Johnson 140HP V4. Since the driveshaft broke, the engine has not run well...it is hard to start and stalls below 2000 rpm. I'm thinking I have to adjust timing, adjust spark advance to correct problem. Does this sound correct to anyone?

Thanks.

 

[jeffersondodson561]

Re: Do I have to adjust timing after replacing broken driveshaft?

I would definately verify TDC, if you broke the driveshaft their is a chance you could have sheared the flywheel key.

 

[bayprowler]

Re: Do I have to adjust timing after replacing broken driveshaft?

when the driveshaft broke, it sheared down by the impeller. the flywheel key is ok and new driveshaft (and new lower unit) functions properly. I am assuming that the timing issue arose when the driveshaft broke b/c the bad engine performance change coincided with when the driveshaft broke. does this sound right?

to determine TDC, I don't have the OMC piston stop tool, but I am using a caliper to find the piston at its fullest extension (top dead center). Will my tool substitution work? I am going off of cylinder #1. I think cylinder #1 is the highest cylinder on the engine, is that correct?

 

[dew2]

Re: Do I have to adjust timing after replacing broken driveshaft?

YES Get er done

 

[jeffersondodson561]

Re: Do I have to adjust timing after replacing broken driveshaft?

I don't have the OMC piston stop tool

Just get a piston stop tool from online or autozone, be sure to disconnect battery when verifying. It's a long shot but if you have a multipiece crankshaft could be offset, verify TDC anyway, always verify before adjusting timing.