XR-6 2-piece prop shaft

[King-V]

I have to start off by saying that this is an AWESOME web site! I'm sure I've already avoided a ton potential problems by reading everyone's posts, so THANKS!

Does anybody know what years the Merc 150 XR-6 came with the 2-piece prop shaft (or do all years have the 2-piece shaft)? If I do have the 2-piece shaft, how much can I surface the prop before I break something? I've been told not to go higher than 1.5" below pad with a 4.5" setback or I'll break something. Bottom line - I want to know if I should buy and install a better prop shaft before installing a nose cone & LWP.

Any seasoned advice appreciated. Thanks!

[CharlieB]

I ran my 200efi 1.5 below for 5 years at 10" set back. I was probably at the limit of where I would consider safe. A Two piece shaft is really 2 parts that are spun welded into a one piece shaft. It is also not the only concern on that motor. The bearing carrier is weak and won't hold up to surfacing a prop for long.

[King-V]

Thanks CharlieB - I guess that means it's best to change to another LU all together if I want to surface the prop to any extent. Do you (or anyone else) know if the CLE would be able to tolerate running the propshaft even with the pad? If so, will a CLE fit the XR-6? I've seen some used CLEs with nose cones for sale on this web site and if one of them will fit my application, I'd consider buying it.

[CharlieB]

don't know anything about your setup but a sportmaster LU is what I went with on my PMax and Bullet. Not sure if you need that or CLE or even torquemaster.

[O/B Dude]

All you need is an Alpha unit. They come on 175's and 200's. The newer models have a chromed steel 1 pc shaft. To check this, put a magnet on the end of the prop shaft. If it doesnt stick, its a 2 pc. I run one on my 260 with a Bob's cone and its fine. Your 150 doesnt put out enough power to warrant the expense of anything stronger than an alpha unit.

I had a pin-preload unit on my 83 2.4 200. Ran it full surfacing for years before the 2 pieces of the propshaft filed for divorce. The prior owner ran it that way for years also. I disagree that surfacing is a bad thing with a 2 pc shaft. It will eventually snap whether you surface it or not. Its more an issue of how hard you drive your boat as to how long it will last. The internals of your XR-6 unit are more of a weak link than the shaft. The problem with the shaft is you never see anything wrong with it before you lose the shaft and your prop, and then get to enjoy a tow back to the dock. :D

[King-V]

Thanks Dude! I've been away from the boat a while and forgot that I wrote this post!

I put a magnet on the end of the prop shaft on my LU and it stuck just fine. Does that mean I have the Alpha unit you are talking about? My mechanic said my motor had the LU of a 200 on it, so judging from your response, I could have an Alpha unit already. My whole rig is only about 1100 lbs (including motor & fully rigged), so at that weight, it might end up being easier on the shaft and carrier anyway.

If the same LU holds up on your 260, would you agree there's reason to believe it will hold up to my 150 even if I tweak it to 200 HP in the future? If so, perhaps I'll put a Bob's cone and LWP on it after all.

Thanks for the advice!

[DK]

I have to agree with dude I know people that have ran the s$#@ out of the EZ- shift gearcase for years without troubles. The EZ- shift is the standard gearcase that comes all v-6's accept the 3.0 L and the 3.4 L. Just one little thing if you are going to swing a big prop or pierce the surface make sure that you take out the fish line cutter and install a regular seal. A fish line cutter is the outside propshaft seal with a stainless cover over the seal so fish line can't get in. When the prop blades pierce the water it will move the propshaft and it will rub on the fish line cutter and score the shaft creating a weak spot and cause the failure that was described above.

[DK]

One more thing some of those xr-4's and xr-6's came with the inline 6 gearcase. If you have the smaller torpedo then thats the gearcase you have. They put that gearcase on because it is smaller and has less drag in the water. But it is weaker and it could blow the pinion bearing out of the side if you push it hard. If you are going to run it hard and you have this gearcasi it would prolly be a good idea to change it to something else.

[King-V]

Thanks for the info DK!

I think I have the EZ-Shift case - the torpedo is just under 5" diameter at the exhaust outlet (4-7/8" diameter I think - it's hard to measure with the prop shaft in there). The case also has a swept skeg and a speedo pick-up notch in the leading edge - does that help identify it? The prop I use is an Aquaholic 14.5" x 28" ET clone, so I guess that counts as a "big" prop.

I had a look at what I think is the outside prop shaft seal and I can't see that there's a stainless cover in there. Are you able to tell if I have that from the attached picture? The seal looks to be rubber.

Thanks again for the advice!

[DK]

Sounds like the EZ- Shift to me. That also looks like a regular seal. Yea that is the seal that I am refering to. If there was a fish line cutter you would be able to see it just by looking at it. The fish line cutter is an extra stainless shield on that seal that covers it almost to the prop shaft. It goes close enough to the propshaft that an averige piece of fish like can't between the two.