It is currently Tue Jun 24, 2025 10:42 am




Reply to topic  [ 5 posts ] 
 Motor Swap 
Author Message
MMT Addict

Joined: Sun Aug 09, 2009 12:50 pm
Posts: 574
Location: Muscatine, Iowa
Post Motor Swap
We are in Process of swapping 18hp Van to 29hp Van on GT-LT 58" frame. Frame started out with a 9hp, and was beefed up to handle, 18hp. Now we are beefing it up to handle 29hp Van, Anybody done this? We are using a worn down MB Tiger prop 11x10", and running it on 14'-48" Short Transome boat. Primary operator will be my 6'1" 275# son. We have done several motor and frame swaps but, have never used 58" frame. Any input would be appreciated.


Sun Aug 30, 2009 10:09 am
Profile
MMT Pro Member

Joined: Thu Mar 26, 2009 1:53 pm
Posts: 77
Location: DE, MD, NJ
Post Re: Motor Swap
I cant offer any advise but I do have a question. Where are you finding these motors for swaps, are they new or used? Ive been looking around for either a 23 Van or larger and can't seem to find any.

_________________
1544 G3 with 23hp GDLT


Mon Aug 31, 2009 12:36 am
Profile
MMT Addict

Joined: Sun Aug 09, 2009 12:50 pm
Posts: 574
Location: Muscatine, Iowa
Post Re: Motor Swap
WhiteLighting, My son and I are the only ones in our area who are willing to work on all makes of mudmotors, we also set them up on boats. The last motor swap we did ,was installing 35hp van on MB-HD Sport, which started out as a 29hp. A tree fell on it and submerged boat and motor, doing conciderable damaged to both. The owner collected insurance on rig and bought a new 35 Van motor from local lawn mower shop. He gave us the 29hp as payment for our labor on swap. We rebuilt 29 Van. All other motors came from Duck Hunting buddies in area. Who either Blew them up or damaged frames beyond their ability to repair. We have access to machine shop and welding equipment. We are always interested in buying or trading for broken Mudmotors. We are not a business and do this as a hobby. Another on going project is installing sponsons on a 18' Sea Ark 18'-72" Jon boat with a 225hp Johnson Venom OB. My sons Boat and our big water decoy carrier. Hopeing to pick up a few more mph.


Mon Aug 31, 2009 8:51 am
Profile
MMT Addict

Joined: Sun Aug 09, 2009 12:50 pm
Posts: 574
Location: Muscatine, Iowa
Post Re: Motor Swap
Finished 18HP Van to 29HP Van on GD-LT 58" frame and water tested it. Plenty of power, Found 9x5 prop to be to small 4250 rpm, gets on plan real quick with load. Needs 10x9 Prop to get off govenor. Frame handles extra Power real good, no stress cracks or Twisting, son says steering torque not bad, about same.


Mon Sep 07, 2009 4:33 pm
Profile
MMT Addict

Joined: Sun Aug 09, 2009 12:50 pm
Posts: 574
Location: Muscatine, Iowa
Post Re: Motor Swap Update
Water tested 18 to 29hp GD swap, we had trouble with keeping prop in water at WO throttle had a tendesy to climb to surface. Must be due to short 58" shaft. We repositiond Tank and battery forward and bent leding edge of cavitation plate down, this helped a little. To add more trim we fabricated up some adjustable trim tabs wich we bolted to skeg, after trying different angles we found a good compromise. Boat plans out nice a 3000rpm with 550 lbs. people, and runs 4150rpm at 23mph. Tiller torque side to side and up and down very manageable. Still going to reprop to 9x7 so motor will stay off govenor with lite load. Shorter shaft length is easier to handle in flooded timber. This swap makes for one hard running GD Crawdad model.


Mon Sep 14, 2009 8:57 am
Profile
Display posts from previous:  Sort by  
Reply to topic   [ 5 posts ] 

Who is online

Users browsing this forum: Majestic-12 [Bot] and 133 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to: