Mercury V6 School for lower units

**nitro_rat** · 07-24-2018, 09:24 PM

Any "big bearing" case that's 2:1 came off a 2.0, they're worth coning in my opinion. My 79m's original "preload" case has been coned since the early 90's. Still holding up. Just popped the power head Sunday on a 8k RPM kamakaze run, It's used to seeing 7200 regularly.

**LakeFever** · 07-24-2018, 09:32 PM

How many variations of lowers are there? Is there a part number breakdown with bearing size and ratio knowledge out there? I have no qualms welding up a lwp nose cone, in fact it would be fun I like to build vs buy whenever I can. I'm really enjoying this stream thus far and really appreciating and enjoying scream and fly. The hunt continues

**Dave S** · 07-25-2018, 11:46 AM

Just buy some spares and don't worry. Then when they start blowing ya ok. The ones with the pin are weaker but good for most stock mercs. The ones with out the preload are better. Better.Did I say..... the race stuff is not need for your application. It says your location is floating a round so I would say a grappling hook ...ya might be able to find some. Otherwise....I would say beat the bush at local yammi dealers for what they call junk and look for deals.

**LakeFever** · 07-25-2018, 11:55 AM

Fair enough so none are bad then and to be avoided? Basically at this stage my line of thought is get a lower unit with LWP so I can surface the prop and start testing props and keep my stocker for back up. Eventually I will add power as I bore and master driving through the power I currently have. First time out I was rolling off the throttle very quickly to get the hull stable, second time out I was wide open for minutes at a time trying everything to go faster. Had prop blow out many times trying to figure out the sweet spot. I didnt even know what prop blow out was I have never had a boat that did this before. Anyways on my lower unit search obviously I'd like to get the best possible value or quality or even better, both

So I want to learn more about what Im looking for. I searched a lot and didnt really come up with anything crystal clear. Seems lower units are where the tight lipped info is for whatever reason I am sure I will learn as I go.

Really trying to avoid buying something unsafe, or something that wont improve on what I already have is all. Seeing as I had little to no luck through search I also figure moving forward others will also want this info, hence this thread.

Would love to hear any and all opinions out there newb or not. Thanks again guys, and S&F I'm having all sorts of fun with this boat, and this forum

As for floating around? Yeah indeed, im all over the place almost never in the same water twice.

**nitro_rat** · 07-25-2018, 12:26 PM

Cone what you have. If you blow it then decide wether to replace or upgrade...

**LakeFever** · 07-25-2018, 04:42 PM

I was all set to do just that at the beginning then read a bunch of negative opinions on the small pre load case so I decided to get another and I like the idea of a ready to go spare anyways. Plus I'm not taking this boat out of service now that its up and running. For now Im focused on learning and I still dont have a clue how many factory lower units there are and what the pros cons are aside from C1 big bearing 200, CLE, and sportsmaster thats about all I know

**gotboostedvr6** · 07-27-2018, 08:57 AM

What's your application? Give us all the details.

**nitro_rat** · 07-27-2018, 09:27 AM

If you want the best combination of strength and handling for your boat, you’ll probably want a 2:1 geared “big bearing” case with a Bob’s cone. The racing cases (CLE/Sporty) are stronger but don’t handle as well on most V bottoms (‘Streams anyway).

Big bearing 200 cases have 1.87:1 gears. You probably won’t be happy with the performance of your 135 with the tall gears. You’ll need a different prop also to accommodate the change in gearing.

There is a big bearing case for the 135/150 with 2:1 gears. It will be a ratcheting case with 2:1 gears and no preload pin on the top of the driveshaft.

My ‘79 Mariner 175 still has its original preload case with bobs cone and has been surfaced on a Hydrostream since 1981. I change the oil frequently and don’t shift while running with tall props.

**LakeFever** · 07-27-2018, 06:03 PM

Originally Posted by nitro_rat

If you want the best combination of strength and handling for your boat, you’ll probably want a 2:1 geared “big bearing” case with a Bob’s cone. The racing cases (CLE/Sporty) are stronger but don’t handle as well on most V bottoms (‘Streams anyway).

Big bearing 200 cases have 1.87:1 gears. You probably won’t be happy with the performance of your 135 with the tall gears. You’ll need a different prop also to accommodate the change in gearing.

There is a big bearing case for the 135/150 with 2:1 gears. It will be a ratcheting case with 2:1 gears and no preload pin on the top of the driveshaft.???

My ‘79 Mariner 175 still has its original preload case with bobs cone and has been surfaced on a Hydrostream since 1981. I change the oil frequently and don’t shift while running with tall props.

This is now the third time I hear the CLE is a no go for this hull thank you! I'm pretty set now on coning a stocker and sticking with a 2:1 which if I have to do twice because I get impatient and cone this stocker I have instead of finding a big bearing i'm still good with that. I have an XR2 with oil inj delete that I am working on to fit this onto and will repower the hull when its done along with a new lower and prop. I'm going to play with some through hub props and stock lower with this 135 for now and work on the second mota as I get time and parts.

Thanks a ton guys and S&F I'm really getting somewhere now.

Also I did find a grenaded early 80's carbed bridgeport the other day with a CLE I assume? Owner says its all original and I was excited to buy and build that but now? I'm thinking the hotter XR2 will do until I find a 2.5 later on and go for the century. I love learning

*edit* speaking of learning this pin you speak of is readily visible with the unit off yes?

**Onetime** · 07-27-2018, 06:18 PM

Call BS on the CLE being no good on your boat but a nose coned Bob’s being good.

Since you’re a 135 HP with a 2:1 case, if it doesn’t have a pin in the top of the drive shaft it’s an ok case and you could nose cone that. Keep in mind if you start running it high surfacing, it will probably start walking the prop shaft seals out.
A CLE, if you can find a good one, will more then likely be 1:87. You can make up for the ratio by running a lower pitched prop.

**nitro_rat** · 07-27-2018, 07:06 PM

Originally Posted by Onetime

Call BS on the CLE being no good on your boat but a nose coned Bob’s being good.

I never said that a CLE was no good, just that most seem to prefer the handling of a coned standard case on a ‘Stream.

Originally Posted by Onetime

Since you’re a 135 HP with a 2:1 case, if it doesn’t have a pin in the top of the drive shaft it’s an ok case and you could nose cone that. Keep in mind if you start running it high surfacing, it will probably start walking the prop shaft seals out.

This is is what I originally recommended...

Originally Posted by Onetime

A CLE, if you can find a good one, will more then likely be 1:87. You can make up for the ratio by running a lower pitched prop.

IMO 2.0’s punch harder and are happier with a 2:1 ratio. Plus it’s hard to find 18 and 20 choppers...

**LakeFever** · 07-27-2018, 09:56 PM

Plan is to leave the boat as it is for this season and I am putting together another 2.0L with a new 2:1 lower and bobs. I considered skipping this step and jumping into a 2.4/2.5 but I have these two motors and after speaking with a long time stream guy who also runs a 2.0 on the same boat I think its worth the effort plus it leaves me new goals to shoot at when I do re-power with bigger cubes.

I was suggested a bobs lower with a 28 chopper and I see no complaints for Bobs so that much I am pretty well set on. Prop? You guys know the drill I'll probably end up with 10 or more by the time I sort this out.

**Krazymaan** · 07-28-2018, 11:16 PM

Just for the heck of it. Here is some numbers on a 4 hole CLE with the long skinny access panel. Kind of an odd ball but who cares.

**nitro_rat** · 07-29-2018, 06:47 AM

Originally Posted by LakeFever

I was suggested a bobs lower with a 28 chopper and I see no complaints for Bobs so that much I am pretty well set on. Prop?

28 is a little steep for a 2.0. I have swung a 27 SRX with mine but the extra 1 or 2 mph wasn’t worth the loss of holeshot and handling. A large ear 24 chopper is my every day wheel. Good hole shot even with passengers. I can spin it to 7200 if I want and mid 70’s. A 26 small ear is one I’d really like to try. 22’s are a lot of fun and don’t give up much on top as long as you can wind the RPM’s without popping!

XR2’s are a great motor! I would add solid mounts, chris carson’s reeds, have the heads cut to 26-28 cc’s, maybe shave the front half a little. Make sure you get rid of all the timing modules or “black boxes!” They will kill your motor! If you split it, I’d look for a non-oiler crank and a top cap/bearing from a small bearing 260. Then fill in the oil pump cavity with marine tex! Get the pro marine rod bolts and metal caged bearings. That combo will pull hard and live!

I wouldn’t worry about the horizontal front swap unless you just have all the stuff laying around!

**LakeFever** · 07-29-2018, 06:55 AM

Solid tips thanks! I love building so I'm more than likely going to tear it all down and go through all of it. This is also why I want to build a lower while Im at it it looks like a fun project and I will hold onto it if ever I sell the 2.0L stuff I have a lower for running ready to go.