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sei mecrusier /omc swap

F

floatin radio

Regular Contributor
former user name of Cannonballkev, couldnt log on so i changed to a new one.
I have a OMC 2.3 and and am on my third outdrive, replace shift cable, followed stuart hastings directions. The last two outdrives were used, didnt know any history of them. Bought complete used boat in the winter for $300, still have old, engine, all parts.
Anyway, my current outdrive is clunking,, just srarted last couple trips out, may be just the clutch dogs not sure, could replace those, not sure what other damage there is.
Boat runs great, finally, redid the interior, not sure i want to just get rid of it, but dont want to put another OMC used drive on it.
I ran across "SEI" and they have a conversion kit and drive and they will make the modification if you buy both from them, roughly $1900. My question is, is it worth that, im not into the boat that much, traded an old hotrod for it 6 years ago, but for 2 grand i could be good to go for awhile, and possibly sell it to upgrade. what do you know about this conversion? thanks in advance
 
same as a 3.0 or close enough not to make a difference.

As to " is it worth it " Question is subjective, not putting down your setup
you have to decide is it worth it to you.
 
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ok, thanks. will decide before next season. boat is still "clunking" along may have clunked a total of 10 times all summer, and i have been at the lake aalmost every weekend
 
Yes, that was true. Was told to try re proprop, but found a used 2.3. I found a link yesterday that listed a 2.3 conversion, but cant seem to find it today. I emailed SEI to find out if they have that option
 
Maybe it was not a 3.0 drive. Below is copied and pasted here from another website, written by one of the best mechanical minds i have ever seen post to a website.

This is how to determine the gearing of a drive. < added by me da Chief.

If it's a 1.5:1 or 2:1 drive it's easy.....3 turns of the yoke will produce 2 prop turns or 2 turns to 1 turn respectively.

If it's 1.43 to 1 you'll have to turn the input shaft more turns.... 143 to be precise. it would be 143 revs of the yoke to 100 revs of the prop etc.... This is where the protractor comes in handy...

For example, with a 1.43:1 drive the input shaft (engine) turns 1.43 revolutions for every 1 revolution of the prop......... If you measure exactly 1 turn of the prop. you would have to measure 1.43 "turns" of the yoke....... 0.43 times 360 degrees would be about 155 degrees.

so 1.43 turns would be 1 revolution + 155 degrees more
 
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yes adjusted acorrding to his specs. when i installed it at beginning of year, it was great , no clunks, shifted smoothly, forward and reverse, then a couple months later it started clunking. not constant, just every once in awhile
 
tech support said they had used 1:94 but the 2.3 seemed to use a higer ratio so he said to go with a 2:4 ratio. not listed on their site but is available
How hard is it to replace the dogs? I am mechanically minded
 
chiefalen said:
Maybe it was not a 3.0 drive.
Click to expand...

If it was anything besides a 2.3 or 2.5/3.0 drive, the prop wouldn't have fit.

V6 and V8 cobras have 15 spline propshafts, not 13.

The notion that all ratio issues can be corrected by prop pitch is not really true. That's cool that they have a 2.4:1 avail from SEI.
 
it was a 3.0, i still have it, and a 2.3, and the 2.3 thats on my boat now. along with a complete 2.3 engine, in case i ever need parts. !7 1/2 foot sunbird. small boat
but will do around 35 with 5 people and a 15 pitch prop. pulls two tubes well.
 
You're shift cable may be worn, or the clutch dog. If u replace the clutch dog, gear set, & the cable you're looking at about $1500-1600 if a shop does the work. If u do the work yourself then u have to shim the gears, & you'll need the tools to do it. They ain't cheap. If it was me, I'd dump the Cobra & go with the SEI. Think about it. No more Cobra shift cable hassles, tracking down parts, etc. & a 3 yr. warranty. In the spring that's what I'll be doing. And u can probably tear down the Cobra & sell the parts on ebay.
 
If everything matches and runs smooth in the shift cables, double check the stroke of the shift cable.
It may be play in the remote, the gearcable may be attached to the wrong 'hole' on the remote shift arm, it may be play in the cable from remote to engine.
Have repaired quite some Bayliners with cobras that had all of the above.
 
It is no coincidence that most of the questions on this board are from owners of 15-20 year old boats with neglected 2.3 or 3.0 drives. Sometimes these rigs are on their fifth or sixth owner, no telling what's been done when maintenance wise. Asking if it is worth putting 2 large into such a boat is pointless. Clearly it is not. These things are worth a few hundred to maybe 2K on a good day. If you put 2000 bones into it, you will take a loss on that money without question. If you look at it as the price of the entertainment value then I guess it would be worth it.
Best advice is to use it until the drive blows up, part it out, and then go look for another dance partner.
 
The SEI had issues in the beginning, but apparently are OK now.

Have you considered that the Volvo Penta SX drive is also a replacement as a conversion?
A good used SX will outlast that SEI drive!
This gets you into "cone clutch" gear engagement, and you get to completely remove the ESA system!
Yes, they are more expensive, but you won't look back!
And yes, there is a correct ratio available for your engine!

Here's one on e-Bay for a BIN of $1,800.
!By5(p7QB2k~$(KGrHqF,!ikEw5b4kd5PBMTp8nmsrw~~_35.JPG

It is an incorrect ratio for you, but the seller apparently offers a full outdrive service, and may have the ratio that you need.

.
 
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I have a 1964 shortbed stepside 4x4 with a V-6 305 BIG BLOCK (yes, thats what I said) SHould I get rid of it also? Cuz its not worth much, because that motor is hard to find part for. Think I will give it to my neighbor
 
Hey don't get pissed off at me! I'm just giving you the facts. You wanna put money into this boat be my guest, but do it knowing that you are not going to recoup the money when you sell the boat. Maybe you'll never ever sell it, what do I know. If you keep it for ten years then you made a good choice to put the money into repairs. If you have to sell it for whatever reason, you be taking it in the wallet. You have to look at it as a business decision, not an emotional one.
I can't believe that there aren't any other boats in your area that can be had for 2 grand that are in way better condition (drive-wise) than what you have now.
 
o2batsea said:
It is no coincidence that most of the questions on this board are from owners of 15-20 year old boats with neglected 2.3 or 3.0 drives. Sometimes these rigs are on their fifth or sixth owner, no telling what's been done when maintenance wise. Asking if it is worth putting 2 large into such a boat is pointless. Clearly it is not. These things are worth a few hundred to maybe 2K on a good day. If you put 2000 bones into it, you will take a loss on that money without question. If you look at it as the price of the entertainment value then I guess it would be worth it.
Best advice is to use it until the drive blows up, part it out, and then go look for another dance partner.
Click to expand...
And if he runs it till it blows up, it's worth what? A couple hundred? If he puts a new drive on it, it will increase, not decrease the reseal value. He should at least be able to recoup his investment in case he decides to sell it.
 
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haffiman37 said:
If everything matches and runs smooth in the shift cables, double check the stroke of the shift cable.
It may be play in the remote, the gearcable may be attached to the wrong 'hole' on the remote shift arm, it may be play in the cable from remote to engine.
Have repaired quite some Bayliners with cobras that had all of the above.
Click to expand...
You may be right, but it sounds like the damage may have already been done to the clutch dog & perhaps forward gear. Once you hear the telltale "clunk", it's time to tear it down to check if there's any damage. Replacing/adjusting the cable if the clutch dogs/forward gear are shot won't help.
 
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never said i was pissed at you, never even mentioned you name! Not looking to sell it to make money, and for two grand for another boat, I would get a $2000 boat, no where near as nice as mine. $5000 is more like what a starting price for a newer boat would be. Total money I have in to this boat is about $700 have done all the work myself, upolstry was giving to me by a friend in the buisness. so for a total of $2700 I think i wiould be good to go for a couple years at least.
I traded an old hot rod for it years ago, and havebt regretted it since. Would I buy another OMC or 2.3, no way!
have a good day, and thanks for you input
 
kracker said:
And if he runs it till it blows up, it's worth what? A couple hundred? If he puts a new drive on it, it will increase, not decrease the reseal value. He should at least be able to recoup his investment in case he decides to sell it.
Click to expand...

Compared to its value right now it's dead even. I haven't seen this boat with my own eyes, but if it fits the profile of a mid eighties intro level bowrider or dual console with a four banger it is probably worth less than $1000. Putting money into it will not increase the value, even if it were in "showroom" condition it won't be worth more than a couple grand. Maybe if the OP put up some pics to show us what we are discussing, we could be more informative.

A valuation "reality check" is pretty easy to obtain. Just take it to a dealership and ask what they would give in trade and how much he could expect if he tried to sell it on his own.
 
Again Im not looking to sell it for a profit, but with it running in perfect condition, with a new interior, ect i could prob get $2000 to $2500 out of it. which would be about what I have into it with an new SEI drive. I wouldnt want to give the headache of OMC to an unsuspecting buyer. Im done!
 
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