1978 13 Classic repower question
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Lakearrowed |
Posted on 01/04/15 - 11:12 AM
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I have a 1983 Johnson 35 ELCTS hanging on the back of it now and it's finally giving up the ghost. One of two cylinders dropping below 100 psi compression and a couple of other issues have helped me make the decision to repower to something newer. I'm going to stick with a two stroke and I really like Yammys. I had a 220 Special on a 22' ski boat and it was a killer motor. A little better than my all time favorite OB, a Johnson GT200.
I got a line on an awesome 2005 Yammy 40 TLRD. It'll give me upgrades over my old motor I like. No more premix and electric trim. I have teens that can't seem to get the oil to gas ratio right, hence the downfall of the old motor.
My rigger has a concern and says that due to the natural negative angle of the 13's transom, the trim feature on the motor will actually be all the way trimmed out and probably in trailer mode in order to get the motor at a proper angle to trim. Is that true? He said he feels that some sort of shimming is in order at the lower bolts to get the motor to sit right. I always thought on an older 13 it's natural for the motor leg to look like its tucked in a little towards the transom. Am I wrong? Any advice on how to hang my newer motor on the back? I'm leaning towards simple is best.
BTW - no matter how I manually trimmed out the old 35 I always felt it was somewhat nose down in flat water and a light load. When I got three riding in the back, that's when it planed out just right for a smoother ride with the nose right in the sweet spot. I'm thinking that with the extra 70 lbs of the Yammy it'll ride a little better. Please comment if you have a similar motor to an 2005 Yammy two stroke on your late '70's 13 and feel free to send pics too. Thanks!
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Phil T |
Posted on 01/04/15 - 12:59 PM
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Not necessarily true.
I have yet to hear of the need to shim any motor due to the angle of the transom.
Mount the motor on the transom 2 hole up as a start and then evaluate to see if it needs to go 3 holes.
2 holes up means the bolts are in the 3rd hole from the top
Top set of holes
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0 <----bolts here
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Lakearrowed |
Posted on 01/04/15 - 1:29 PM
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Thanx for your input Phil. My rigger is awesome at setting up 800 to 1000 HP BBC and V Drive set ups. I just don't think he has a lot of experience on 13 foot whalers with 40HP outboards! I think he's overthinking it a bit. I'll show him your response to my post and any other comments I get from you guys out there with experience. Any thoughts on the curvature of the transom and a good fit? SS washers and lots of 4200?
Thanks.
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Lakearrowed |
Posted on 01/04/15 - 2:10 PM
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BTW - right now the transom is virgin, no holes. The Johnson was clamped on. Will be drilling to mount the Yammy.
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Phil T |
Posted on 01/04/15 - 2:27 PM
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Here is a good reference article and measurements for drilling the standard BIA pattern:
http://www.whalercentral.com/articles...icle_id=82
Whatever you do, do NOT allow the installer to use the blind holes.
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gchuba |
Posted on 01/04/15 - 2:41 PM
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I would recommend making a template out of 3/4" plywood. You can clamp it at several different heights as you determining which holes to use as well as a guide to prevent a drill tip wandering. Also useful if you need to angle up the lower holes slightly for clearance on the interior of the transom.
Garris
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Lakearrowed |
Posted on 01/05/15 - 12:41 AM
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Thanx guys. I'll show your comments to my rigger. I'll probably shoot his way this week to get a grip on this. I appreciate your comments and I'll post the results once we get the motor hung on her. I can't wait to feel what that Yammy will do for this sweet little boat. Last winter I kitted her out with a new interior and exchanged the pulley steering for mechanical. It made a huge diff and I had a blast fishing our lake in her last summer. Caught tons of smallies and largemouth with my girl and used her more than my go fast boat! It's a lot of fun to tinker with these boats.
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blacksmithdog |
Posted on 01/05/15 - 5:20 AM
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Don't be hesitant to beat the rigger upside the head if necessary. A friend repowered his late 1970's vintage Montauk and told the dealer to mount the motor higher than the previous one was (it was sitting on the transom). When he went to pick it up, the new motor was sitting on the transom as well.
We'd like to see pictures of your rig when it's done.
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Geo |
Posted on 01/05/15 - 5:29 AM
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I ran an 1986 Yamaha 50 2-stroke on my 1969 13 ft. Whaler and never needed shims to offset the transom's curvature. Just be sure to drill the holes that allow you to move the motor up or down instead of the pattern that fixes the motor so that it can only sit flush on the transom. I used large stainless steel washers for the lower set of bolts on the inside of the transom because that is where you will see that the hull will compress the most. Be sure to occasionally free up the through bolts since they are a major pain to remove if they get frozen in the hull over time.
Edited by Joe Kriz on 01/05/15 - 10:40 AM |
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Lakearrowed |
Posted on 02/11/15 - 10:55 PM
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So I finally got all of the little bugs worked out that one encounters when re-powering. Electric trim works, Older analog tach works, motor is at the proper height. All cables and wires nice and tidy. So getting her wet was the thing to do today here in Sunny SoCal. I'm relived to say she ran like a dream. She tracks, steers, and over all handles better with this motor than with the old 35. I'm still smiling from ear to ear. Crazy holeshot and most def faster now. She's like a new boat. Can't wait till summer.
Thanks for all of the great input. I learned a lot from all of you and I'll pass along what I learned to anybody here that needs it. My personal page Lakearrowed has a pic of the new 50 on the back. I'll post more soon.
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