Finally took out the new motor. 26.5 HP EFI Kohler BW LT 59" swomp. The versa mount was installed "inboard" style per Jake's recommendation, on my 2004 1648 tracker grizzly. Boat was carrying me (205#); up front was "ballast" cooler and tool box, marine starting battery. Calm canal and entry to marsh, light wind <5 mph, 66 F. Per the Tiny Tach 2A the motor idled at c. 1120 rpms. I had installed motor on middle/center hole; I may move it up to the last hole to tip a bit more motor weight forward.
Motored smoothly up to 16.5 mph, c. 3000 rpms, but then prop and tracer plate kicked out.
Put in one shim per instructions and it was only a bit better but still blew out. Applied second shim and improved again a bit but still blew out, so I could not achieve full running rpms/speed. I had read that you can break the shims in half and get another shim but found that only one of the screw bolts that holds the tracer plate in place is long enough so did not try, did not want chance damaging or losing the plate while running. My only criticism at this point is that there should be more shims and several more and longer screw bolts. Will address to Jake. Also wonder if the standard clamp on mount might serve me better?
Turning radius is much better than my previous standard 72" drive, and my 59" is shortened another 4-5" by the versa mount inboard style.
EFI so far is very smooth power transition from idle to full- out of water right now because of the shimming problem. Love the tubular frame and the whole assembly is well thought out.
Ran through some vegetation, did not venture far because the water level is low, but had no problems powering in- right now the marsh is better traversed with an airboat; we need another 4-5" inches of water.
With more tweaking unit should be fine, I would recommend the BW line of LT's to one and all! Just the easier turning and easy running at lower speeds is an improvement over my previous MB LT. I was glad the motor came with a friction lever style throttle, "set it and forget it", great for cruising, and keeping firm control on the tiller handle, although I did not need to- my shoulder is not complaining one bit!
I think that, just like hawilson found out with the same motor, a 9x6 prop may be a bit better. My last motor was a 27 and was rated for a 9x7 but I ran 1-2 mph better with a 9x6.

Glades, where was your bump stop set? Try using the forward hole. This will move the motor back a little and should help keep the prop on the water.


Sent from my iPhone using Tapatalk

Stu, the stop is set so that the prop submerges about 10 inches. Does that seem right? I was thinking the back hole- that will move up the motor a couple of inches- wanted a bit of weight shift to the front to reduce effort needed to push down on handle to bring prop out of water. Remember I have the versa mount on the inside. I will try another shim or two and see what happens. I need longer cap screw bolts.

Back the bump stop till the prop is as low as it will go. If it doesn't blow out, raise the prop with the bump stop a few inches at a time till it's at it's highest point without blowing out. If that doesn't help, your gonna have to change the pin position to move the motor aft.


Sent from my iPhone using Tapatalk

Thank you both! Will try the bump stop first, and if this does not help, will try moving motor to front hole.

I'm curious, why did you go from a 72" to a 59" shaft length? I would think the angle of the new motor would be a lot different than the old MB LT. Am I wrong thinking this or is the BW frame setup differently?

Primarily to reduce turning radius while maintaining same speed. When I weighed all the factors for a new motor, I concluded more speed was not needed, a longtail is the best fit for where I hunt, distances traveled, etc., and the price is much more affordable. With the versa mount, I can actually get a flatter angle; right now the problem is getting the right trim (shimming, bump stop, motor base hole location) so that the prop does not blow out.

I am no expert by any means, but I took the bump stop totally out of the equation. I ride with it set all the way up. I let the motor find its proper height on its own. It digs at startup but rises right up with increase in speed. In fact, I found the bump stop, when set lower, can cause blowouts especially in rougher water. As the boat would bounce so would the engine and as the engine came down it hit the bump stop and bounced back up causing a blowout. I really only use the bump stop while trailering. I run with 2 shims. I called Backwater for additional shims as I was experimenting and they sent me 2 more and longer screws also. Never did use the additional shims though.

Good advice, this morning I emailed Jake to see if I can get some more shims and longer screws. Yesterday I was eyeing an old rubber dive flipper and thinking about cutting that up for a shim! That is why this forum is real good, good folks and good info!

You'll get it figured out for sure with these fellas advice.

Look forward to seeing how she runs after you get her dialed in!

Sorry, will try to get out tomorrow am. I did run the motor at home. Noted rpm's ran from 1200-3700. Noted the throttle plate is similar to carb motor; am tempted to advance the little bolt/nut to push the bar farther meaning more rpm's? Is this safe to do? I also noted pre-cleaner filter around main round air filter. Would you advise to remove or leave on?
Regarding the inline gas filter, it clearly states 10 micron type, guess I won't mess with this and when I change it will use the same.
I have prepared a fourth shim if necessary to try out; cutout a rubber piece from an old dive flipper.
Won't mess with the engine main bracket hole position unless shimming does not work; I will have to do this at home, no way I will try on the water by myself!

You'll get it dialed in. I fished and ran a few trails at Holiday this morning. It's gettin skinny out there.


Sent from my iPad using Tapatalk

Could not sleep in, went out! I owe you all some cold ones! The BUMP stop was the problem! Moved it up and out of the way and it ran 18.5 mph no problem no blowouts but a bit deep; took out one shim, left one on and it is about perfect! Idle to full ranged from 900-3470 rpms. I think the next step is trying without any shims, and then getting a 9x6 prop, should realize 20 mph which would be most satisfactory. The cool thing is how relatively effortless it is to steer! EFI rocks, starts right up after a few seconds to fill the pump? I am also going to try to move hole position to the back hole- meaning moving the motor up a couple of inches- would like to make it a tad easier to push down on the handle and elevate the prop; this will help when you're in the veggies and the cavitation platet gets loaded down. I am sold on this motor! Did not venture into the marsh because it is too skinny and plenty of coral rock jutting up just below the surface sure to crack the prop. Big thumbs up to all who chimed in and I can finally sleep this week!

Good to hear Glades. There's several adjustments on your set up. You might find a bit more speed but 18 is just fine. The trails are shallow out west. I took an airboat trail from my fishing spot to just short of the ramp. Took some digging here and there, lost my nerve and got on the L67 canal at the first opportunity. Enjoy the new motor.


Sent from my iPhone using Tapatalk

Glad you got that resolved. Continue to dial it in and you'll know when it's right.

Yeah, man, good feeling after it ran true! I am staring at the sky and looking at the radar, going to try and get out today...have to change out the trailer bunks and figure it will be easier to drop the boat in the water to do that, have to sort out the tools, charge up the cordless drill. Have to order that 9x6 soon, one of my obsessions is to always be ready for teal season!

Closer to perfection! Took a run after advancing the throttle and removing the shim, ran without one. No prop blowout! SE wind 7-10 mph, ran both east and west on the canal, saw 19.7 and 20.3 mph at 3800 rpm! Really cool. Have about 1/2" of travel yet on throttle plate; will try longer screw bolt like hawilson suggested. Definitely will order the 9x6 prop. The cavitation plate and prop finally ran like you see on the BW videos, right on the surface! It was just me with tool box, battery, and cooler up front, could probably use a bit more weight.
I definitely want to move the motor forward to the back hole, this is about 1.5" and should improve balance of motor to make it easier to push down on the tiller and get the prop up.
While I had the boat off the trailer, I put on some new trailer bunks, definitely easier that way! Will try cypress next time, they come a bit bigger and require different size brackets and bolsters.
Based on my last motor, after 20 hours or so more running, will change to synthetic oil.
Thank you Backwater and all of you who steered me in the right direction!

Good to hear. You should pick up another mile or two per hour after the motor loosens up and the prop wears in.

I would bet 3800 is about all you can get with that 9x7. I think I got 3850 when 9x7 prop was new. Now turning 4100 with new 9x6. If you end up going faster than me I'll have to get a different rig. Can't have someone going faster than me!!!! Good luck and keep us posted.

You better start shopping for a new hull, hawilson! It is glorious to hit 20 mph on a longtail! This does not mean I will sleep an extra half hour either! I'll still get there early and surprise those teal.

hawilson, did you remove the foam pre-cleaner from around the air filter? With my older carbed motor, I removed it- I think the motor ran better with more air flow.
The fuel filter is supposed to be a 10 micron type- I've looked online and can't find this specific one. I don't need to change it just yet, but want to have the right one!
I will try and order the 9x6 this week, itching to try it out!
Also having trouble finding the longer machined screwbolt that pushes the throttle plate; pretty sure it is a M4 size, need one about 1 3/4". Any ideas?

Yes, I did remove the pre-cleaner. As far as the bolt size I don't remember the exact size. I just took it out and brought it to Home Depot or Lowe's and matched it up.

Spook too soon.i believe the screw I used was an M4-.7x40mm pan head. Hope this helps.

Yes! Of course, HD did not have any...going to try Lowe's. That length should push the throttle plate all the way to the slot stop. Thanks!

Well, found the longer M4 screw, pushes it almost all the way to the slot stop...had to back it off a bit because otherwise the idle would be way too high...ordered the 9x6 prop today, might get to test it next weekend. Got 4150 rpms out of water, cool for now with the 9x7; took off the foam pre-cleaner from the air filter- after all we are not cutting grass just water veggies! Picked up some E3 plugs, I want to believe they were better than the Champion RC 12 YC...wishful thinking maybe.

Glades, why the 9/6 prop? Just curious.


Sent from my iPad using Tapatalk

You realize a few hundred more rpms and this usually means 1-2 mph more; this was the case with my previous 27 hp mb lt.

Same scenario with the 20hp Honda MBLT I used to run. Everyone recommended a 9X5, I went to a 9X4 and gained load carrying ability and speed unloaded. Basically it was easier to turn no matter what. The Honda liked to rev too.

I went from 9/5 to a 9/6 on my 25 hp gdlt and picked up 3 mph.
Looking back I know the back float pods on that GD 1844 were severely water logged. I wonder what the 9/4 would've done.


Sent from my iPhone using Tapatalk

Thanks Glades. I was under the impression (incorrectly), that if I went from a 9/8 to a 9/7 that I would get a better hole shot but loose top end.


Sent from my iPad using Tapatalk

Stu, it is not the same for all boat hulls and motors, you see what flint87 reported. But you'll never know until you try it! I want to have a backup prop at all times....would not be easy to do in the marsh, but if you have all the tools, probably doable....I cracked a 9x7 MB Tiger prop some years ago, it was coral rock, and had to push pole/ paddle back a couple of miles....still have a new bow mount trolling motor gathering dust, that is my next project. That prop video Frank posted is good, but like some others, I sometimes need a stout breaker bar. Regarding prop size, I remember reading about LT's running at considerable elevation, they did not necessarily benefit from a smaller prop size, but I figure the EFI should benefit ignition/combustion of the motor. I would like to hear from anyone running one in the western plateaus.

9x6 prop came late yesterday in the mail, took off the 9x7 and put the new one on! Got up early this a.m. and dropped the boat in the canal. A big smile took hold when after warmup, I slowly took it up to 4100 rpms and the GPS read 20.7 mph! Only .4 mph more than the 9x7 but it held steady at that speed, there was less than a 5mph wind, whereas the 9x7 seemed harder to hold that speed. I bumped 21 mph a couple of times, what a fine thing that was! This might be all laughable to the shortail >30 mph crowd, but I am happy. I think I will leave it at that; the only other tweak is to move the motor bolt to the rearmost hole to give a little more weight forward balance. I have not needed a shim since sliding up the bump stop- thanks for that advice! I am officially ready for teal season!
hawilson, you don't have to buy a new hull just yet!

Good deal Glades. Looks like you've got it dialed in.


Sent from my iPhone using Tapatalk

The Backwater hype is real!! Haha

The Backwater ownership is real! Arlin is first class and an awesome guy. A manufacturer that can boast ZERO product warranties during their life history has a fine product! A manufacturer that drives 1300 miles to come hang out with a bunch of mudmotor enthusiasts at Caddo has my support!

That hair, though. I'm gonna have scissors or clippers next time I see him

19something was the last time he got a haircut! That was awesome!