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Old 01-05-2011, 07:55 PM
DANNY18SC DANNY18SC is offline
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Default 18 with a 90?

how do you think me 18 will perform with a 1990 90 hp Johnson with a 17 pitch prop? it is a 20" motor and my transom is 25". should i look for a 25" midsection or cut the transom?
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Old 01-05-2011, 10:40 PM
Fr. Frank Fr. Frank is offline
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Default Re: 18 with a 90?

You need more than just the midsection; you need the right driveshaft to go with it. Don't cut down the transom. Let me repeat that: Don't cut down the transom.
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Old 01-06-2011, 09:48 AM
DANNY18SC DANNY18SC is offline
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Default Re: 18 with a 90?

since your boat has a 90, seems my 18 CC would do fine with a 90 and one day i could look for a bigger motor. anyone know of someone with all the 25" pieces for a 1990 90 johnson?
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Old 01-06-2011, 09:54 AM
uncleboo uncleboo is offline
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Default Re: 18 with a 90?

I agree with Fr. Frank, don't cut the transom down. I wish mine was a 25". I don't have any problems with the 140 4s on my 20" transom, HOWEVER, you won't see me going out in snotty conditions. I spend most of my time in the Albemarle Sound and only go in the ocean on nice days.
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Old 01-06-2011, 05:15 PM
Bigshrimpin Bigshrimpin is offline
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Default Re: 18 with a 90?

http://www.baymfg.com/

This is what you need to make that 20" motor a 25"
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Old 01-07-2011, 01:04 AM
eggsuckindog eggsuckindog is offline
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Default Re: 18 with a 90?

You really need a 25" 115 at best, I bet you can do with a sale/swap in those years pretty easy. Sell yours and buy a 115, should be pretty even and easier
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Old 01-07-2011, 01:31 AM
Bushwacker Bushwacker is offline
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Default Re: 18 with a 90?

Quote:
Sell yours and buy a 115, should be pretty even and easier
I agree - if you add the $ you'd spend on the 25" extension kit to what you'd get for current motor, you might be able find a newer 25" 115. The 90 (used to be an 85) and the 115 are both V-4's, so same block and about the same weight. However motor condition/compression is more important than age. Would be best to get a loop charged model (60 degree V) instead of the older cross-flow 90 degree V, but I don't know when they started making the loopers.
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Old 01-07-2011, 10:14 AM
DANNY18SC DANNY18SC is offline
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Default Re: 18 with a 90?

im trying to work a deal on a 140 looper. the guy has an extra motor and the extension kit. i dont have the cash at this moment since i just bought the boat but am trying to work a trade. thanks for all the input and advice!
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Old 01-07-2011, 10:52 AM
Bigshrimpin Bigshrimpin is offline
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Default Re: 18 with a 90?

Some of the 88 and 112 special motors were crossflows into the 90's. v4 loopers were made in 90 - 140hp flavors (beginning in 86 or 87) . . . same block, same bore and stroke. I don't know for sure but I don't even think there were porting differences. You can do a little research . . . It's probably just changing carbs, heads, and tuner will be the difference b/w 90 and 115. This is true for Merc 2.0L 135 - 150, and 2.5L 150xr6, 175 vs. 200. Sometimes just swapping carbs will give you the extra 25hp. Visit www.screamandfly.com and you can figure out the differences in very little time.
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Old 01-07-2011, 03:38 PM
eggsuckindog eggsuckindog is offline
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Default Re: 18 with a 90?

Probably the biggest deterent to working 20+ year old motors is trying to actually do it. Bolts break or won't come out and it just becomes a nightmare of time and aggrevation.
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