Driveshaft will not go back in!!!

[ToddW]

So after spending over an hour trying to get the drive shaft to go back in I've officially given up for the day.

I've tried over and over, it gets snug then slides in another .5" then stops... it's about 2" from being totaly in, gets to this point all the time, my guess is that's right where the splines engage. problem is I can't freely turn the shaft at this point to line up the splines.

I then had my bro grab the coupler and lift up as hard as he could (almost lifting ski up) and I could barely move the shaft to try to find where the splines go, but still they wouldn't line up and go in.... seems the engine is a couple mm angled to much and I can't get it lined up enough.

Any tricks to getting this baby lined up and slid in? I can't line up the splines by myself AT ALL due to the tightness of the install, and even with a second person he can't hold the weight long enough to line them up.

My next thought was to use the cherry picker to put some pressure on the coupler/internal shaft but am afraid this may cause seriou sproblems???

-Todd

 

[keefer]

If the engine is not shimmed properly it will push or pull the midshaft into a position that will make it act exactly like you are describing. While the pump is out you need to get the alignment corrected. The pump should slide right in once you get this done. The only other reason is if the splines on the midshaft are really damaged. If you move the engine away from the coupler I would bet that the pump will slide right in. This is a further indication that you are way out of line and need to re shim the engine. If you do not correct this, you will wear out the mid & drive shafts spline section because they are in a bind. You should NOT have to force the pump into the midshaft.

 

[ToddW]

Can I just use a couple washers to shim the rear of the engine up a little or is there more to it then this?

-Todd

 

[headshock]

Had the same problem when I installed my prop, I spent about an hour working on it then removed the intake grate and slowely worked it in there. I used the method of pushing it in then when it didn't budge pullin it out and moving the driveshaft a degree or 2. This worked for me within 20 minutes. All of the work was done by myself from the bottom of the ski. I took the precaution of removing the plugwires from the plugs first.

 

[ToddW]

I'll keep trying that then, maybe prop the engine up a lil... why remove the plugs or wireS?

 

[keefer]

You have to get the engine setting in the mounts so that the coupler halves are level at the top and bottom. Check out the pic below of the Yamaha manual page about shimming the engine. You can use washers but it might be hard to get it right. Get some Stainless engine shims of various thickness and go to it before you destroy expensive parts.

 

[RideItLikeYouStoleIt]

I had this problem before too. Loosen the 3 bolts on the midshaft and put the driveshaft in. Then tighten the 3 bolts down. No problems since.

 

[ToddW]

You have to get the engine setting in the mounts so that the coupler halves are level at the top and bottom. Check out the pic below of the Yamaha manual page about shimming the engine. You can use washers but it might be hard to get it right. Get some Stainless engine shims of various thickness and go to it before you destroy expensive parts.

View attachment 32921

Coupler is in spec, I'll take pic to verify but to my eyes and tools its level.... I've put 10+ tanks through it too, how many tanks would it take to notice coupler measurement issue?

I got the dshaft in, just loosened rear motor mounts and bam it went right in, it's only off by a couple mm if that I think.

 

[ToddW]

I had this problem before too. Loosen the 3 bolts on the midshaft and put the driveshaft in. Then tighten the 3 bolts down. No problems since.

Thanks, could have done that too! :biggthumpup:

 

[keefer]

Did you check the coupler alignment with the rubber dampner removed? It will look ok if the dampner is installed and will fool you into thinking it is ok. If you have to pry on something or remove the midshaft coupler bolts then something is out of whack and you need to correct that. The pump should slide in easily if the splines are lined up. If you run it in a bind something will eventually wear out prematurely.

 

[RideItLikeYouStoleIt]

Well, If the the midshaft is sitting at the bottom of its mounting position it wont ever go in smooth. There is alil bit of play as to where the midshaft can be mounted. Not much but a couple mim. Mine is in pretty much perfect allignment checked with a micrometer and it would not go in smoothly. It would go in smoothly everytime after i put the driveshaft in and then tightened the bolts. I think you should probably mount the midshaft in place while having the driveshaft into it. Even with no motor in the ski if the driveshaft is sitting too low in the mounting position it wont go in. Ive put about 10hours on it since i did this its still in alignment and no signs of wear on driveshaft splines. This is my application though and its very important the engine is shimmed properly.