Is it possible to still get a new KB 3.5?

[Lowell Tryon]

Robert, I went and bought some new batteries for my calipers so I can see the digital reading instead of relying on the slide-scale... 12mm cranks it is

 

[camaroboy383]

Ok that's great it seemed fine.. will save you some headache.. if it siezes at any point it will spin the outer race and woller out the case... bad news bears!.. I've only seen one lower do it and it was not greased just like yours..

The 12mm crank version is ok, at least you have two of them.. I'd honestly either make one good one and use the other for parts, or go for it and put a buggy engine on those lowers /or one lower..

Sorry I spaced on the inboard you bought, side exit inboard?

 

[RobertDoak]

I had some alignment issues with the TT lower bevel gears....with a little work smooth as butter on the mesh...I do like the oil cavity on the TT lower....full it up and go.....

 

[RobertDoak]

So I was thinking....the TT lower is actually the way to go in this day of outboard....my thought is this...almost no selection of affordable powerheads options....but...the rc car buggy word is loaded with motors....the only issue is the back cover pto...some machining may be needed to the pto...and the cooling head can be cut down..

 

[Lowell Tryon]

Yes, I’m definitely going to attempt to get two good lowers out of this. As to the inboard motor, my thought was if it won’t work in outboard, I might build an inboard someday. But, it is side exit exhaust, so with a standard u-shaped header for a buggy, could a buggy pipe then mount up and fit between the head and lower? I’m thinking the answer is no or I’d have seen photos already.

 

[RobertDoak]

Lowell..
All parts from the inboard should cross over....not the crank....the sleeve/piston shouldnt be an issue..
If for some reason you want to sell a pto from the TT hit me up...looks like you Alden and myself are restarting a Cult with the TT....haha..

 

[Lowell Tryon]

Hah, yeah these tt’s are so much more mechanically interesting than the the other outboards, I guess that’s why I like them! I tracked down a TT distributor in Germany that has quite a bit of spares left, but they’re expensive to get over here.

Perhaps if I ever have time I’ll draw up the PTO housing in solidworks and see if I can get our machinist at work to make me some...

Should the replacement bearings I get for the lowers be shielded or not? the ones I removed were fully enclosed, but if I’m going to be adding grease to the foot...?

 

[camaroboy383]

The bearings for the lowers will come sealed...as well as the pto bearings...

Pull the seals from the lower bearing, but leave the seals in the pto bearings.. when I assemble the lowers I put a fair helping of grease in the forward cavity that houses the bearing...I will pack the bearing first... then fill the cavity to the top.. this prohibits water from getting in that side...i will then cover the lower and upper bevel teeth before bolting the lower up.. this should be done after every outing.. clean the old stuff out, check all bearings, and reassemble... better safe than sorry...

As a side note.. the flex shaft will never see any of that grease applied and must be cared for separately... the factory tt shafts are, eh, well they work... tt had several iterations of these shafts... the holy grail of them will be impossible to find these days I'm sure... there was a run that had one single gold wire wrapped through it... those were the best tt shafts made... I personally used shafts that gabe Clegg was selling when he owned oer... I had great success with them.. I beleive they were made by lawless..

As for the pto housings, I already have them modeled in fusion 360 and most of the cam is done as well.. may be able to send it to the cnc mill soon... while this solves the problem of no pto's available, it doesnt cure the low availability of the lowers themselves.. I've though about casting them, but, it's just not worth it...the harsh reality is nobody uses these anymore...hell, they were barely used when they were available...

So lowell, I'm very curious, I know those tt's you got were 12mm crank versions, now the important part, is the prop shaft right or left hand thread? The very early lowers were threaded right hand, and guess what happened? Yup the rotation of the assembly unscrewed the prop shaft! That run was very limited but they do exist.. check yours to make sure...

Ac

 

[camaroboy383]

Oh and prop shafts! The drive dog is secured to the shaft with tiny roll pins... if you tighten the prop nut to much it will bend the pin and bind the prop shaft... if you want to use the factory setup you will have to leave the prop so the nut just touches it, you should still be able to move the prop on the drive dog, hope that makes sense...

best thing you can do is push that pin out and insert a solid tool steel pin.. I use drill bits, just cut a section from the shank.. put some red loctite on it and press it in..

 

[Lowell Tryon]

Wow, you really know your Thunder Tigers! The pin is missing in the busted motor, I already grabbed a steel pin from the machine shop for it. Luckily, I guess, the prop shafts are left hand threaded.

Good work on the PTO preservation project! I was thinking the other day how the housings would be a good experiment for a metal 3D printer, the result probably wouldn’t be strong enough, but I’d like to try... Just have to find a metal printer first!

 

[camaroboy383]

The strength would be plenty sufficient.. it would still need to be machined regardless of the manufacturing process.. I use all my 3d printers for prototyping before the gcode is sent to the mill... I will post pictures of the process of the pto when I get time to prototype it. .

Left hand threads are good, cause you wont ever find one of the right hand threaded prop shafts... looks like your doing just fine..

 

[RobertDoak]

Alden..
Is the TT setup the same....as if a donor motor is used...the crank must have a pull start style crank for the xlong pin to drive the pto..I'm just taking all this info in..

 

[camaroboy383]

Yes that is correct... its "easiest if the pin already exists"... for instance the o.s .21 vz does not have a pull start, the crank pin must be drilled and a slug pressed into the center of the pin with great precision... it can be done, and has... its slot of work!

 

[RobertDoak]

Ok..then that truly opens a wide door to choose from..then the only other issue is the pto cover to engine case...

 

[camaroboy383]

I'm currently working on that robert... the cad is done... working on the cam operations...

 

[camaroboy383]

That being said it doesnt solve the issue of the lowers and gears being unavailable, so be gentle on your lowers boys... keep em greased and keep good bearings in them

 

[RobertDoak]

Words of wisdom....and will be taken with great caution....the TT my be bench run only to test of it works...but im building a new boat for it specifically for it...so its no hurry..
Thanks Alden..
Lowell....and whats up with the batteries in these measuring tools....my just pooped out...and you just replaced yours..

 

[Lowell Tryon]

Heh, my calipers are Harbor Freight specials... The ultra high precision of them requires a lot of juice

 

[Lowell Tryon]

I should mention, I bought a 1.04 gearset from the TT distributor in Germany on ebay. They claim to have 2 more sets. Cost me $41 shipped which is almost what I paid for one of the motors, but looks like it might be the last place on earth with them in stock. In the mail right now, let’s see if it’s legit...

 

[camaroboy383]

Yes, I saw them on ebay.. he does have several different parts for them for sale... it will take some time to get but I'm sure it will all work out...