alignment

[777memaw]

I have two mercruser 260 hp 350 engines one has a shaft nine and one half inches long the other is 8 inches. the tool goes in all the way on the nine and one half but only goes in motor coupling about one half inch on the 8 inch b4 it bottoms out. this does not seem right. any input would be a big help

 

[rodbolt]

Re: alignment

can ya get the seriel numbers off the drives?<br /> sounds like someone has installed the wrong shaft on one of the drives. never saw a GM V motor with the 8" shaft.

 

[Bondo]

Re: alignment

Ayuh,........ <br />That Short Shaft drive is for a Model 1 , Pre-Alpha, In-line GM engine.........<br />That'll Destroy the Coupler,.. In a Hurry,... It's only engaging 1/2 the length of the Splines......<br />Been There,..... Done That........<br /><br />Aside from that,......<br />I say That Engine also is in Serious Need of Alignment.........<br /><br />Either That,......<br />Or,...<br />Your Boat has been Seriously Cobbed Up........

 

[777memaw]

Re: alignment

It is a 1978 century that I have owned since 1996 never had a problem with the motor coupler but when I use this tool it botoms out and it is only in the coupler half inch the other boat is 1984 mark twain with 9 and one half inch shaft the tool goes in the coupler all the way

 

[Bondo]

Re: alignment

It's entirely possible that the coupler has started to get Torn Up from the short shaft,....<br />And, you can only insert the Bar That Far.....<br /><br />I ain't trying to rain on your parade,....<br />But,.. You WILL be having Problems with the 78....<br />The Shaft is Too Short.....

 

[777memaw]

Re: alignment

it seems really strange to me that this boat has been set up like this for the 10 years i have owned it with no problems last year i put over 5000 miles on her on the loop or great circle route

 

[Don S]

Re: alignment

Rear motor mounts go bad, then the back end of the engine drops down. Then the coupler starts wearing very quickly. <br />Just because something has worked for 10 years doesn't mean it will never break, unless you live in a completely different world than the rest of us.<br />The tires on my truck were new only 60,000 miles ago, why would I have a blow out now??????<br />See what I mean.

 

[777memaw]

Re: alignment

the rear mounts were new last year b4 my trip this shouldn't have anything to do with the 8 inch shaft being a problem

 

[Bondo]

Re: alignment

I can't find it right now,..... But,....<br />Wait a minute,.... I just found this,+ scanned it from my NAPA marine parts catalog,......<br /><br />

<br /><br />The Short Input Shaft is Only used for the GM Inline motors with the Pre-Alpha drives.......<br /><br />You've got a V-motor,....<br /><br />Possibly,.... The Coupler is Worn where it's only engaging 1/2 the splines,+ the Alignment Bar is Hitting on the point where the Worn Out splines turn into Good, unused splines.........

 

[777memaw]

Re: alignment

ok the motor coupling also was new last year. I measured from inside the spline where it stops to where the outdrive bolts on is 16 1/2 inches on the drive itis 16 inches from where it bolts up to the end of the shaft this is the 8 inch shaft. Now I measured on the other one it is 18 inches from the end off the spline in the motor coupling to where the drive bolts on and 17 inches from where it bolts on to the end of the shaft.

 

[Bondo]

Re: alignment

Well,......... Ya Got Me.......<br /><br />The 78 sounds like a Mongrel,.....

 

[777memaw]

Re: alignment

OK thanks for your input

 

[I/O WALDO]

Re: alignment

I wunder if your coupling is the NEW type that has a longer nose extending aft and the old style alignment tool will not go in to it to the splines?Is it a big triangle that bolts with 3 bolts on the outside the flywheel or the old type that screws in the cntr., to the crank?

 

[Fishermark]

Re: alignment

Here is the service bulletin describing what I/O Waldo mentioned:<br /><br /><br />

 

[777memaw]

Re: alignment

thanks guys but it is the new tool and the old coupling it appears to be hitting the top of the coupling so i assume the motor needs to come up in the back

 

[Bondo]

Re: alignment

I asked this over There,.......<br /><br />Is there any chance the Transom is starting to Rot,+ Sag,+ possibly be Causing your Alignment Issue

 

[777memaw]

Re: alignment

thanks Bondo but the transom is solid there is somthing i read somewhere about the new motor mounts may or may not need a shim i think i may. the boat only had 400 hours when i bought it in 96 i don't think it has been cobbled

 

[I/O WALDO]

Re: alignment

How bout raisin the engine up in dee ft ,memaw?Is your Century an Arabian? (They were NOT a mongrel of a boat!)I thought old Century's were Ford powered?

 

[777memaw]

Re: alignment

thanks Waldo I tried that right now i am looking for the shim that goes under the mount mercriuser #35777 nobody seems to have it or knows where to get it