Thought I would try to put up a few pics of this project that has taken a back seat to others for so long now. Chiseling at my bucket list has brought it back around to the front burner.

This is a Drakart (Extreme, i think? I forgot it’s been so long) The Geo Engine was walked off and I am working towards a repower with a 2009 R1. It should be my ultimate buggy when complete. Most recent work is the final fit and alignment of Engine to FNR. Making the mounts has been tricky with all the funky angles and support spots that the bike used. Bothe the Engine and the FNR are rigid. I intend to use a weld-on sprocket tensioner since I have that extra real estate on the left side Engine bracket. Fuel tank will be above the FNR. I don't like that but there’s just no room anywhere else. The battery will fit behind the seat, maybe the ECU, and a few other bits, but that's about it. I trimmed the nose off of the air box to keep it behind the seat. I will add an “outer wear” top try to keep sand out of the filter and/or maybe add an formed aluminum shroud with the little room I have there. Sequential shifter will be on left with a shifter mounted lever clutch.

Anyway. Hope someone here appreciates the interest remaining in our sport and if you see me doing something stupid feel free to speak up… I mean other than strapping 190 HP to my sand toy that is.

Something like this for the fuel tank. Choices were limited but this might yield just enough room to mount a radiator between air box and tank.. up as high as possible.

That things gonna be a beast, love it. Can’t say having the gas tank outside of the cage is a great idea though. Maybe add a little loop around the gas tank? Or modify the down bars in the back?

I sure agree and was actually thinking the same. I just have the tank propped in there in that pic. In its final form it will be sticking out but not nearly that much.. ands some added protections are a great consideration. This is one of my passion-projects here… Thanks for the kind words!

I have to agree, that thing will be a rocket.
You going to do anything about possible chain stretch ? Tensioner ?
CO

Edit: I'm thinking something along the lines of a spring loaded style like the Murtfeldt (non sprocket type) Chain Tensioner. In my experience as a millwright they seemed to work well. I don't like the lever arm type with the rubber tension element. They worked but not well in an industrial type setting.
CO

Thanks for the tip. I ordered a TC Bros weld-on unit. With everything welded/bolted up rigid-mount tight at both ends (Eng/FNR) I felt some kinda tensioner was called for. Plus it will help, like you say as the stretch comes about.

I also ordered a Moroso oil filter tap to relocate the oil filter. I do not know that I will need oit but this could also provide means to add another oil filter. The R1 already has an onboard water cooled oil cooler loop. But In the event I need I like to have the option.

I think I may be considering too large of a fuel tank. This one shown is 4 gallons U.S. In the bike, the R1 was capable of 45mpg or more.. less in this use obviously but still I don't know that I need to carry more than a couple gallons. I will be making dune runs, playing around, and then returning to the trailer to refuel every so often.

The R1 is internally balanced so vibration shouldn’t be to awful. If you mess with the tune be prepared to burn more fuel, stock tune shouldn’t be a problem with that size tank. I had a zx10 tuned and it was
Unreal how it went through fuel. The fun factor outweighed the go back and re fill factor every time though.

Right on. I do have a little space behind seat, under the header/collector. But its nothing like what was there with the geo Engine. I might load up some geometry and form up some aluminum and find someone that’s TIG superior to me. I could likely trim up and reuse the fill tube, cap, vent and feed nipple from the old tank.

Video of wheelies, rooster tails, and drifting will be expected.

Oh yeh. This thing is a good bit of work. I will post up something for certain :)

Anyone know how to calculate volume if I were to bend up this trapezoid tank out of some .090 aluminum and find a local TIG Pro? I am thinking it’s at least as much as what the GEO carried around before (see round tank) or pretty close thereto. Looking at it, I could even splay the sides out at an angle and make just a touch more if I wanted to do the extra Mango.

Fill will be the fill tube from the round tank and I will send it into the little flat plateau section at the top end. Feed and vent bungs will be reused too.

If you broke that down to measure 3 boxes you could get a fairly accurate calculation.
In that first picture you only provide the angled measurement to the black line.
The issue I see is that you do not provide (in the first picture) the measurement from the table to the black line and then from the black line to the top of the box. Also the length of the black line on that face.
I may get a close measurement if I had that info.
The real guy to ask would be adnoh but he don't show up here anymore.
CO

Sorry for confusing dims. Those lengths are the full height/width of the edges. That black line means nothing. I get 634.5 cubic inches. Or about 2-3/4 gallons including the fill tube. that's got to be an 80 mile range conservatively. I am trying to keep the tank at least 1-1/4 away from headers. I may wrap headers and/or do a heat shield too. Thanks!

If you could fill it with those little bean bag styrofoam beeds, or something like them, you could then pour them into gallon jugs.

And be sure to wrap those headers to insulate the tank from the heat.

No sir you are wrong in my opinion.
Based on those measurements I get 5.8us gallons.

If you just go by the bottom part of that tank from the black line down and do those calculations of 11"x6"x17 3/4" that's already 5us gallons.
A plastic five gallon fuel jug is 11"x7"x15".

Yes I know it's a "slight" trapezoid but not much.
Just my opinion.
CO

Edit: I'm obviously not taking into account the thickness of the cardboard and I'm just using the measurements I see there, but at most, if the cardboard is 1/4" thick it won't make to much of a difference.
If I take into acct the thickness of the cardboard (1/4" + 1/4") the calculation for that box (black line down) works out to 4.3us gals.
Now you have to add those two little boxes located on top of the bottom box and that's another .8us gal approx.
So you are looking at a 5us gal tank.
CO

Wow great idea.
I like it. I'll have to keep that idea in my mind. Hope it don't get lost.
CO

That is a good idea. Thanks.

I have modified it to have the ends splay out more now to fill an otherwise empty space. So more volume.

Using length averages to compensate for the angled sides, etc…
18 X 6 X 8.5 = 918 c.i.
Minus the cut-out.. 15.25 X 2.5 X 4.75 = -181
Plus half of the filler neck… (V=πr2h) = +29.5
918 - 181 + 29.5 = 766.5
1 gallon = 231 c.i.
766.5/231 = 3.3 US gallon.

Closest it gets to the exhaust installed is about 1.5” and I am still planing to wrap and maybe even shield the exhaust. Although boiling fuel @ 70psi might make up for no turbo :)

Yes sir it's 3.3 gal.
That's what I'm getting now.
I must have been putting in wrong numbers last night.
CO

This is turning up pretty sweet! Quite a geometry exercise!

Nice

That Is looking awesome, nice to see you back on it.
Looks like you are getting close.

Here are pics of the one that was built for the Briggs. I believe 5 gallons and change it holds. Rusty did like you and made it out of cardboard first. Has baffles to help with fuel sloshing around.

Interesting project, looks cool, up your life insurance and start saving for new rear tires

Briggs still around? You should be sending him photos...

Very cool. similar work. I also did 2 baffles inside. I like that one, nice!