Merc 9.8 70' - 71' Thunderbolt Ign.

[OBJ]

Ok guys, big time mech here needs some help from you Merc fans.<br />I got the above motor I been tinkering with for a while. Replaced stator module and one ign coil, points and wireing. Rebuilt carb also. Got it running easy enough with a couple pulls on the rope. Problem is I can't get it idles down. It's idling way above specs to the point I don't want to put it in gear. Timing is retarded as far as it will go and the idle screw is at the point where just a touch will cause the engine to stall. Idle screw is approx. 3/4 to 1/2 off seat. Followed the procedure for timing and when I get the dial indicator set at .193btdc and adjust the timing screw to adjust timing to the point break, I have a meter across the points, the throttle arm is so far down on the cam I can't get WOT. What am I doing wrong????<br /><br />Sincerly...Brain Dead At Shop :confused

 

[steelespike]

Re: Merc 9.8 70' - 71' Thunderbolt Ign.

Outboard jim,This is from a 1965 pocket service guide.Procedure if degree plate tool is not<br />available.<br />Set stator to position where magneto cam just touches the carb pick up lever.Turn crank until <br />Breaker arm is on the high point of the cam <br />(high point is not at the key way but to the left of the keyway.)Adjust the points to .020.Adjust<br />the second set the same way.If the cam is not<br /> cut into crank be sure it is tight and installed <br />with arrow in the direction of rotation.<br />If the keyway or key is damaged it will throw off the timing.Obviously this is a different year from yours but what do you have to lose.

 

[alcan]

Re: Merc 9.8 70' - 71' Thunderbolt Ign.

Hi OB Jim<br />If I had the Ser# I might be able to help.

 

[OBJ]

Re: Merc 9.8 70' - 71' Thunderbolt Ign.

Hi alcan....<br /><br />Serial number on the 9.8 is 2849216. Any info will be appreciated.<br /><br />Thanks steelspike also...I'll take a look on this also.<br /><br />Jim

 

[Chinewalker]

Re: Merc 9.8 70' - 71' Thunderbolt Ign.

Hi O.J.<br /> I would disconnect the throttle arm that attaches from the verticle part to the armature and advance/retard it by hand to see if it is in fact a timing issue. See if you can idle it down from there.<br /> Also, check to make sure the butterfly in the carb is closing fully - I had one of those lose the screw and the butterfly cocked so that it wouldn't close.<br />- Scott

 

[alcan]

Re: Merc 9.8 70' - 71' Thunderbolt Ign.

Jim post your email address and I'll send you some info.

 

[OBJ]

Re: Merc 9.8 70' - 71' Thunderbolt Ign.

OK alcan...<br /><br />mudcatmary@attbi.com or<br /><br />matt@1st.net<br /><br />The first one is home and the second is at the shop.<br /><br />Thanks mucho to all for the tips and trys...Jim