Driveline issues...

[maxum-mama]

Hi all! It's me again (I'm the one who hit the sandbar last summer and thought I blew the motor, but turns out it was just bad timing... NOT my fault! LOL)

So... last year we lost our motor after only a couple months... one of the pistons was fried on our '90 Force 120 Ldrive. We looked into having just the one fixed, but were warned that if one was new and the others old it would work unevenly and make the old ones fry too... SOOOOO, we shopped around and found a '93 120HP that isn't an Ldrive. Got the motors switched out and all was working well, except for the last step... connecting it to the lower unit. The drivelines don't match up! One has 13 splines and the other has 15 I think. Any suggestions as to where we can have a special driveline made? We looked here in Spokane WA area, and found one place to do it but they want $500 for it. Seems a little excessive considering it's about a 4" long piece.
As soon as we get that piece made, we'll HOPEFULLY have a boat again for this coming summer! Any suggestions would be helpful!

 

[Frank Acampora]

Re: Driveline issues...

Oh, Good! A girl to make fun of! LOL

NOT to be the voice of gloom and doom, But I recently found out that L Drive engines, while the same block, rods, and pistons as outboard engines, had the crankshaft balanced differently because of the different orientation of the block. Using the outboard block, you MAY find a bit more vibration I don't know-- couldn't tell you effects for sure, but it may work well also.

Now I know in the later Force engines that Merc made with a Merc midleg and lower unit, The crankshaft and drive shaft had fewer splines. So, perhaps your 93 block is one of these. If you can find a trashed lower unit real cheap and cut off the splined end of the drive shaft, an EXPERT welder could join it to the L Drive end --probably for about 100 bucks labor. --Either that or for 0 bucks and your labor, dismantle the block and install your L Drive crank into it. That option, although time consuming, also has the advantage of being factory balanced and in my opinion would be the better choice if the crank is OK.

Do not let dismantling the block scare or intimidate you; if you can get the block off the mounting, you can disassemble it. However, buy a manual. There is a specific procedure for reassembling the connecting rod big ends.

 

[bayliner12]

Re: Driveline issues...

how would you possibly hook a non L drive power head to an L drive power head, thers all those u joints and stuff