Sei conversion question

[ruggles]

I am thinking of doing the conversion to the alpha 1 but I have a question. Can you use the conversion kit with an actual
Merc alpha or does it have to be an Sei drive? The reason I'm asking is two food. First there are some good affordable used ones for sale and second I'm sure they're of better build quality than the sei.
Thank you.

 

[southkogs]

You're in an OMC forum at the moment ... what are you converting from?

 

[Bondo]

Ayuh,.... The SEI's are dimentionally identical, so each drive will fit where the other will fit,....

 

[ruggles]

I'm converting from an omc cobra to the alpha. Just wondering if I can just buy the kit and use an alpha 1 gen 2 merc leg instead of the Sei units

 

[alldodge]

Replace the transom assembly

 

[ruggles]

No there is a kit that bolts up to the omc housing. I'm just wondering if the sei alphas are modified at all versus a legit merc alpha

 

[G_Hipster]

I'm thinking, by the time you buy the kit, and maybe a shifter, and a used drive that might or might not need work you might not be far off from someone getting inside and repairing the drive you have.

 

[ruggles]

My drive is fine. I'm done fucking with the cobra shifting is all. Comes out of adjustment constantly. I used the tools and followed the directions and still issues

 

[Fun Times]

I'm just wondering if the sei alphas are modified at all versus a legit merc alpha

The typical upper and lower drive shaft housing units are typically considered to be the same....Nothing would normally need to be modified between the two brands.....But with reading the details of the SEI kit, SEI says there is a small modification to the drive that needs to be done plus they sell a drive labeled as Modified complete... I'm not sure of what that may entail though so you may want to try giving them a call to see if they're willing to explain if no one chimes in here that's already done this...Plus it seems they would rather you call with "your" boat details before just ordering a kit so that may help get a better answer. If you do call, let us know too for future reference.

http://www.sterndrive.cc/product/Fit...rsion-Kit.html
http://www.sterndrive.cc/Mercruiser-...onversion.html

• Replace 1986-1993 Cobra drives that shift in the lower unit.
• Does not replace King Cobra drives.
• If you have a fuel injected motor with the shift bracket at the front of the engine, please call us to order.
• The throw of the shifter must be changed. You may need to purchase a new shifter
  if your current one cannot change the throw of the shift cable.
• 300HP Limit.
• You will need to purchase a new prop and hardware to fit the SE116 drive.
• This kit does not keep the function of the trim position sensor. You could make an adjustable L bracket to activate the plunger.
• Designed to work with our SE116 drive.
• The drive does need to be modified slightly.
• If purchasing the drive, please note that you will want to purchase the install kit and anode kit at the same time.
• If the drive is ordered at the same time as the Conversion kit, we will modify the drive at no charge.
• SE116 1.47 Mod. Complete (Replaces Mercruiser Gen II)

^ Without fully knowing, I was just about to let you know of one possible exception that you might of needed to be aware of... On the older Gen1 drives the input shaft (U-joint shaft) lengths came in different sized lengths and could affect/compromise the engine coupler if not a correct match....But being the kit fits the SEI116 drive unit, that unit number is compared to being the Alpha Gen 2 drive unit...Not a Gen 1 unit so it shouldn't affect this install.....Unless the unknown mod is to change the shafts length to fit the conversion.

Should some more info become needed covering the shaft sizes, follow the two lower links within this link, http://forums.iboats.com/forum/engin...9#post10308189
Notes from SEI: SE104 drive unit = Short Yoke (Replaces Mercruiser's Alpha One) while SE106 = Long Yoke/Shaft (Replaces Mercruiser's Alpha One) 116 = Gen One.

 

[Scott Danforth]

you get a new drive from SEI with a warranty for about the same money you get a used drive, with unknown background if you get a mercruiser unit and it may or may not fit the SEI conversion......

two options. either go with the complete SEI conversion package. or find a used boat with a rotten hull and swap out the mercruiser stuff complete.

 

[ruggles]

Thanks guys. I'm going to call a local place that sells the conversion kit to get more info. I'll report back once I have.

 

[bruceb58]

I was looking at your last thread where you were adjusting the cable. Just so you know, it is normal for the drive to grind a little when going into gear if that is still your issue you are worried about. The Alpha will do the exact same thing. Also, if your console shifter is worn and not giving you enough throw, no amount of adjusting of the shift cable will solve that issue.

 

[ruggles]

I've decided to get a new remote shift cable as it's original to 1991. I'm pretty sure the throw isn't enough. I'll buy an oem transom shift cable this time as well. If this doesn't work this time I'll be selling the boat. I'm also going order a new greasable bellcrank as mine has a flat spot. I'll pulled the drive this weekend and winterized the motor. I also noticed a small amount of coolant in the bilge. Most likely the water pump is starting to seep. Are the ones on amazon decent? They are only about $100

 

[Lou C]

When you set up the cable did you check to see if the throw was equal in fwd and rev? When I did mine not only did I have to do the transom shift cable but I had to do the remote cable as well. Did you start with the shift rod height adjustment on the lower unit? Everything hinges on that, if this is off it will not be right no matter how much time you spend on the other adjustments. Then, did you measure the cable drag, with the cable disconnected at both ends? Less than 2.5 lbs with a fish scale? That's the other critical thing. When I did mine, with the transom cable disconnected at the engine bellcrank, (ENGINE OFF) I shifted it in and out of gear with someone spinning the prop and marked on the cable itself, how far it was from neutral to fwd and neutral to rev. Then when I hooked up and adjusted the remote cable, I made sure it was the same. If not either the remote control is worn out, or the remote cable adjustment is still not right. They are not that hard to get right if you get the shift rod height right and have a good cable and control. I did mine in 2013 and its been great ever since. Before that, the last time it was done was 11 years before!. I only had to do it because the remote adjustment changed. So I went back and re-did all of it.

PS, I don't think I'd trade a good running Cobra for an Alpha. I like being able to change the water pump in 5 minutes, and having a bellows that is not a battle to change. And OMC's shift assist system, is superior. It does not stall the engine like Merc's can as long as your engine tune and idle speed are right. Yes it is hard to find mechanics who know them, but if you make sure all those points are covered, it should be good. I suspect your control, cables or remote cable adjustment. Keep in mind that the Alpha is not so different, its dog clutch shifting in the lower unit, with a 2 cable system. Same basic idea.