What jackplate for my xtb-21

[hotdog87]

I just bought a 1989 XTB-21 and was wondering what size jackplate works best on these hulls? Can some of you 21 owners give me your oppinions???
Thanks,Jeff

 

[John S]

When I had a yamaha, I used a 6". With a merc 2.5 I finished at 10". Rite hieght has a really cool unit.

 

[Blue Gray in PA]

I used the factory 6-inch plate with my 150 HP Mariner and added another 5-1/2 inches (hydraulic) to see how it would carry the bow. I left it that way when I went to the 280 HP Mercury. I'd like it to be a little closer now because it sits really low in the water and the higher HP should be able to carry the bow better. The added weight of the hydraulic trim unit on the 280 makes the boat sit even lower in the back when the boat is at rest.

Just another FYI - Bill told me he thought the jackplate bolts were locked into place inside the hull, but when I tried tightening the lower bolts, they did turn. Mine is a 1989 model too but apparently they locked the bolts together in later models. I'm thinking of cross-drilling the end of the bolts to be able to hold them as I loosen the nuts - if I decide to change the factory plate. The other alternative is to remove the gas tank and weld a plate between the lower bolts so they can be tightened or loosened from outside the hull. Just my .02

 

[mtolley]

Jeff, how was vacation? hope that the trip went well. look forward to meeting you soon! mike t

 

[froggy]

Back in the day, when my 1985 XTB-21 was new, Darris recommended a 4" plate, I had a 6" already installed. I went to a 4" plate and lost 5mph. I was pizzed so I moved my batteries around while bobbing in the water and got the 5 mph back.

I'd go to 6" to 10" of offset and then work on load distribution and props.

froggy

 

[hotdog87]

Thanks for all the info on the jackplates! I picked my trailer up on Monday from Mike Tolley in SC. It was nice meeting you Mike. We need to keep in touch with other!!! After picking up the trailer,headed to Richmond,Va. to get the XTB from Frank Huddle. Who let me and a buddy of mine,stay the night at his house. Thanks Frank for being such a nice guy,also thanks for the boat. I love it!!! We got up early Tuesday morning and floated the boat onto my trailer,and headed back on the long trip back to southeast Tennessee. I had a XB-2002 before and really think I`m going to like this boat as good or better than it!
I also want to say that everyone that I have ever had any dealings with from this website are all fine people!!!

 

[mtolley]

Jeff, it was good meeting you too! you will have post up some good pics of that floater you bought. i know you had a long 2-day trip, and im glad you made it home safely! we will keep in touch, call anytime! mike t

 

[motobuffy]

Thanks again Jeff. I certainly enjoyed your company! I know you will have the ole girl looking like a new dime in short order. I do think you should share a pic or two of the boat as it is currently rigged. I'm sure it would kick off a completely different set of thoughts and comments! I doubt many would have experience with the set up or would be able to offer prop advice, but... No, I'll just stop here and let you spring it on them.

 

[mtolley]

Frank, i think i still have the pics of the boat that you sent me on my cpu,but i will only post them with Jeff's permission. i believe they are with the yamahammer still on it. mt

 

[pacman809]

Jeff-

I run a 10" Bob's set back on my '87 XTB as it was recommended here by the pros and I've haven't been disappointed. 200 EFI pushes a 26" Trophy to stable 82mph.

Pacman

 

[motobuffy]

Mike,
What is interesting is what he has on it now, albeit only a temporary situation. Old pics won't tell the story. But it is up to Jeff to decide if he wants to share.

 

[ericgolf69]

I have the Allison 5 inch now on 21 XTB and did not want to stack so I was going to buy the 10 inch TM Hydrolic jack plate. I am glad i read these as i just thought from my past exp. that the 10 set back would work better , I was going to add an 8 inch to my 5 inch but thought that miight be a little much with a 2.5 Mercury with a 28 chopper and it will turn over 6000 RPM really quick . What do you guys think. I had a 1979 XST that I did some hull work on and had a 280 dyno engine on it and it ran over 100MPH

 

[ericgolf69]

What do you Allison pros think about me just adding a hydrolic 5 ,6 or 8 inch jack plate to the one i have on there ? Or should I just take the one off and adding a 10 or 12 hydrolic on there ?

 

[SLOmofo]

Pro not me. I like a fixed setback plate. Best to have only one plate, less nuts and bolts to loosen and break. Hyd plates move at different rates depending on amperage. Thus you might be just a little tooooo high= bat turn. Or low BTDT. Maybe call the factory.

 

[ericgolf69]

I go by Allison quit a bit as i live 15 mile from them
Just wanted to know. If I have only one , I may have to pull my gas tank out to put the 10 inch on there, but I have a 5.5 on there and if i put a 6 inch on there with it ,will be an easier install

 

[ericgolf69]

Pro not me. I like a fixed setback plate. Best to have only one plate, less nuts and bolts to loosen and break. Hyd plates move at different rates depending on amperage. Thus you might be just a little tooooo high= bat turn. Or low BTDT. Maybe call the factory.

I only live 15 miles from Allison

 

[ericgolf69]

I quess it`s time to go and see Glenn Reynolds !