MC-1 Drive Dog failure?

[ratdude747]

Had a frustrating outing today with my 1976 MC-1 (888 302).
It's always been hard to not granny shift without slamming the throttle (both directions)... but today was particularly bad (would not engage)... but then we seemingly hit something at the end that wildly nuked two prop blades on my 4-blade composite piranha...



... and with that blown up prop, it was nearly impossible to get it engaging without rev bombing, especially in FWD. RWD didn't seem to be nearly as bad.

Sure, I lost half my prop area... but I fear that whatever happened took my drive dogs from bad to worse given that one direction seemed to be worse off than the other. I've already fixed the prop (Had two spare blades, hub survived), but am hesitant to run it any more if there's any reasonable chance that there's a ton of metal in my oil. What would be the next step, drain outdrive oil and look for metal?

 

[alldodge]

It's always been hard to not granny shift without slamming the throttle (both directions)... but today was particularly bad (would not engage)..

The first part of your post leads me thinking the lower shift cable needed to be replaced before this happened

Checking the lube would be a good thing

 

[ratdude747]

The first part of your post leads me thinking the lower shift cable needed to be replaced before this happened

Checking the lube would be a good thing

Bad cable or just needing an adjustment? Looks like I'll have to pull the outdrive to replace, something that was originally on the list for this last off-season until I discovered what I thought was dry rotting bellows was actually cracked dirt (no dry rot)... if an adjustment would get me through the rest of the season, I'd rather not have to pull the drive in the middle of the summer. But if it's boned, it's boned.

 

[kenny nunez]

After losing the 2 blades the open cavity let exhaust blow out around the propeller, the exhaust bubbles ventilated the propeller blade surfaces.
Try it again to to see if anything has changed.
As AD said you need to perform the shift cable adjustment procedure.
There is an excellent procedure on this site with a video that should help.

 

[ratdude747]

After losing the 2 blades the open cavity let exhaust blow out around the propeller, the exhaust bubbles ventilated the propeller blade surfaces.
Try it again to to see if anything has changed.
As AD said you need to perform the shift cable adjustment procedure.
There is an excellent procedure on this site with a video that should help.

I saw the video... and yeah, that makes sense about the prop being windowed.

Looks like an adjustment is in order... my next outing won't be for (at soonest) three weekends from now (have commitments the next two). And then we shall see.

 

[ratdude747]

It ratchets both directions in both FWD and rev. Definitely needs checked.

 

[ratdude747]

Seems something is indeed shot. Went through the adjustment... even with the lower cable stud all the way up (which is how it was originally), I can't get engagement in both directions with the throttle lever. If I manually pull the lower cable, it does engage as it should... so lower cable gone sloppy?

 

[nola mike]

Seems something is indeed shot. Went through the adjustment... even with the lower cable stud all the way up (which is how it was originally), I can't get engagement in both directions with the throttle lever. If I manually pull the lower cable, it does engage as it should... so lower cable gone sloppy?

Maybe. Run through Achris' adjustment video on youtube (is that the one you looked at before?) and pay special attention to checking play in the shifter cables.

 

[ratdude747]

Maybe. Run through Achris' adjustment video on youtube (is that the one you looked at before?) and pay special attention to checking play in the shifter cables.

Nope... But watching it now. I'll check the wear but I'm pretty sure it's out of spec. He did mention that 1976 is where 6" on the lower cable started and before it was 5 7/8". I think my serial is in fact 1976... but if not, maybe that's part of the problem?

 

[ratdude747]

Im getting 13/16" of slop. Max allowed is 9/16"... So 3/16" out of spec. Cable replacement time?

 

[Eric 3.7LX Alpha 1]

Yes that is a lot of stretch in the lower shift cable, and why you can't get both forward and neutral to engage. It's going to be a pleasure to shift in and out of gears once you get the new one installed. I don't 100% remember what I used for the "special tool" to un-thread the lower end of the shift cable from the bell housing. It was either a 9/16" spark plug socket with a hex nut on the end so another socket could connect to make it deeper, or a 1/2" drive deep socket in 9/16".

Don't forget to run a guide wire up the outer cable after you remove the inner core before you pull out the outer cable, it will make the job much, much harder if you forget the guide wire.