'72 50hp question about spring tension on throttle mech.

[jbjennings]

I'm about to set the timing using Joe Reeves method on this motor. I've noticed that if I back off the timing stop, that the spring tension is not enough to advance the timing to the timing stop. I believe this may be causing me not to get quite enough spark advance. Has anyone had any experience that the spring can lose tension from sitting for 30 years? I had thoughts of getting a new spring, or trying to add a little tension to the current spring so it would pull a little harder, after using a timing light to determine if it needs to go farther than it is now to get the full advance.
Anyone have a similar problem or have any advice to offer?
BTW, all parts are greased properly.
thanks,
JBJennings

 

[oldcatamount]

Re: '72 50hp question about spring tension on throttle mech.

I doubt a spring would lose tension just sitting, it's probably not the original spring. I suggest getting a slightly shorter spring or re-configure the old one a little.

 

[boobie]

Re: '72 50hp question about spring tension on throttle mech.

I may have read your question wrong but is your timer base nice and free or is it binding up??

 

[Joe Reeves]

Re: '72 50hp question about spring tension on throttle mech.

What spring? If you're speaking of the large coiled spring that is incorporated within the vertical throttle lever..... it's highly unlikely that anything is weak in that area.

Suspect a slightly tight timer base retaining clamp. If so, either bend it up slightly or put a very thin washer under the tight one. If no tight clamp...........

Grease can be your bitter enemy. Grease "only" the brass bearing portion of the timer base and the related surface of the top main bearing area.

DO NOT grease the timer base nylon retainer ring. Make sure that it and the related portion of the top main bearing area is perfectly clean, THEN use only oil to lubricate that nylon retaininer ring. Grease collects dirt, dirt causes binding!

 

[jbjennings]

Re: '72 50hp question about spring tension on throttle mech.

Thanks for the info guys. I used your method Joe, for setting timing to 15 degrees, 19 being spec (hopefully that is correct). I discovered the spring was sufficiently pushing the timer base far enough as you already knew. I hopefully haven't greased the wrong place, but everything appears to be working fine and timed correctly. I even got a used stainless prop in the mail for it on ebay in flawless condition with factory spec pitch of 13 1/4 x 17 for 89 bucks, so it should really run smooth. I'm really excited about testing it tomorrow evening and expecting it to run like new. If possible, I'll borrow the wife's phone and take some "transom shots" of it running and post them, as I'm really proud of it, seeing how it's the first motor I've repaired to such an extent.
Thanks again,
JBJennings