Vintage Open MSPTREX Zebra

[MSPTREX]

Late entry with my zebra but I plan on starting on it after the taco is finished. As of right now the plan is to use taco 22 forks, a built hemi predator, old school raised edge tri-stars, and a bright color that I'm still undecided on.

Frame is rough. Someone added foward pegs and the clutch side original foot peg is completely missing which left a huge hole. I plan on replacing the missing pegs and undecided on leaving or removing the added pegs. Foward pegs might be nice when taking tight turns but we will see. Rafa at Gt's Hobbies copied the taco 22 forks and I plan using them with the build then I will call the bike "The Zebra Taco" haha

Motor I have in the picture is a hemi predator I slapped a Honda tank and cover on since I bought motor with them missing. The plan is pretty basic build with a +20 rod, flywheel, non-hemi head I already have (head has 26lb springs, stainless std size valves, and roller tip rockers), and most likely a decent size cam. Still unsure on what carb to run.

Excited to start on this one. Should be fun with the built up predator and small tires!

 

[cheezy1]

:thumbsup: Thata boy

 

[MSPTREX]

Haha told you I would cheezy!

 

[mrpat]

Very cool. I love me some zebra tacos..lol. Should be a fun project and a great rider.

 

[chipper]

Right on , double action!

 

[MSPTREX]

Just a little update, still slowly collecting parts for this build. I did tear down the Hemi to get ready for the motor build and tossed in a rod. Stock piston with an +.020 ARC rod leaves it sitting pretty good almost flush with the deck.

Later this week I need to assemble the rest with stock springs to check my piston to valve clearance. I forgot that the rtc-6 head I had for the build not only is ported but has .070 taken off it and I have a decent size cam/rocker set up for the build.

If everything clears I will have my machiest buddy do a valve job for the new valves and put in some bronze guides. I'm thinking with a thick fire ring headgasket I will have room to make the parts I have laying around work.

 

[MSPTREX]

Well I learned something new a couple days ago when I decided to clay the predator to check my piston to valve clearances . Stuck my cam and lifters in, went to assemble the head, and the retainers would not fit on the valve.

Now the head I have is a rtc-6 from a non-hemi. I grabbed a set of stock gx160 springs and retainers from the garage just for quick assembly while checking clearances. Evidently non-hemi heads have a 5mm guide and valve stem and hemi/honda have 5.5mm. I don't have the stock springs or retainers so I gave up and decided to drop the head off to my machinest to have finished.

I'm pretty confident with a thick fire ring gasket I'll have room but I'll still check after head is finished to be sure. The head will get some work done by Smithberg Racing. He is a busy guy so hopefully he gets to it in the next couple weeks. I have been ordering more parts for the build. I will have to get more pictures of the pile of parts soon.

 

[MSPTREX]

Now my other build off bike is pretty much finished I can focus more on this one. The head is still at the machine shop since i told him I was not in a huge hurry. I drug the frame in from cold and got some better pictures before I start fixing the frame. The frame did not have a brake when I bought it so I ordered a brake from the taco website and it fits fine.

Someone added foward pegs which I actually like and plan to keep but clean up the welds and fill in the holes. The clutch side foot peg is completely gone leaving a big hole. I plan on replacing it and hopefully fill in the hole and get it smoothed out before powder coat. I had Rafa at Gt's Hobbies make me some early taco style bars for the bike and should be here anytime.

I will also bead blast the wheels and decide if I'm going to have them burnished or coat them. I made the round cylinder gas tank out of stainless and it will mount on the factory gas tank mount on the predator. As of right now the plan is to coat it Candy Electric Blue.

Tons of parts ordered and waiting to be used. I will get more pictures of the parts and forks soon.

 

[MSPTREX]

Got the wheels bead blasted last night. Trying to decide on getting them burnished or not but leaning towards letting cambo61 work his majic. Also marked all the holes that need filled on the frame and things that need added/fixed.

Reminded machinists about my head and of course he forgot about it haha said he will get to it soon. My custom repop taco bars should also be here next week from Rafa. Only difference between regular early taco bars and ones I had made is the space for the fork tube is almost a 1/4" bigger on a zebra over a taco.

One other thing I did was take a bunch of measurements for the talented Manchester1 for when she gets time to tackle my seat for the project.

 

[manchester1]

You should watch OldMiniBikes facebook live tonight. Eric show you all the stuff with the predators.

 

[SAT]

Nice work. Straight threads or tapered NPT on the fuel tank fill? I've always been reluctant to take-on a fuel tank build due to chronic leakage around the fill. Tanks shaped like yours are cool.
Steve

 

[MSPTREX]

Tapered NPT on the gas tank. It is just a 3/4" stainless npt pipe plug. I built one just like it for my Ruttman I will add a pic of it.

 

[MSPTREX]

Got an update on my rtc-6 head for the build. He got the 5.5mm bronze guides installed, finished up the porting, got the spring pockets cut, and shims found to get correct spring install height. He also port matched the intake for me and will have him do the same for the header pipe when I choose one. Should be all done soon and can start on motor assembly.

 

[MSPTREX]

Some progress on the frame. I have a clutch side foot peg again but wasnt finished welding when i took picture of it. I got all the other unwanted holes filled in and decided to remove the foward pegs just havent got to it yet.

Received my early taco forks for the build from Rafa at Gts and i think they will look great on the bike! They will confuse the unknowing since zebras are not all that common.

Also mocked motor/clutch and rear wheel/sprocket to cut my wheel spacers. Mocked up front wheel to make spacers for the front as well. Few of the small things already blasted like gas tank, brake, and pulse pump plate. Project is coming along quick and will have color on it soon.

 

[MSPTREX]

Sent my raised edge tri star mags out to cambo61 today to get burnished. Can't wait to see them looking new again. Once they are back I will get them assembled and take some pics. Debating on getting a slick tire to run in the rear but still undecided.

 

[MSPTREX]

Talked to Cambo61 today and man he made the old tri star mags look great again. Can't wait to share pictures of them when they show up this week.

Also got word this morning my cylinder head is finished and ready to be picked up. I most likely won't have time until the coming weekend to make the hour trip to go get it. Pretty excited the build is taking form quickly.

 

[MSPTREX]

Got my wheels back from cambo61 and like always he did an amazing job! Would definetly recommend him for any of your burnishing needs! I think these old school raised edge tri-star mags are going to look great on this retro bike!

Worked on getting things sand blasted last night and I removed the foward foot pegs. Got most of the stuff blasted besides the frame itself. Hopefully find time to finish blasting it soon and get ready for powder.

 

[manchester1]

Wheels look great. Slow down.:laugh:

 

[MSPTREX]

Picked up my cylinder head on Sunday and was able to get motor 90% assembled. Head turned out great and flowed just under 70cfm which is really good for being 27/25 stock size valves.

First thing I did was clayed the motor since I was worried about piston to valve clearances. Well I didn't need to be. Just over a hundred thousandth piston to valve clearance so I have a ton of room to grow if I want to later. Going to see how over powering it is going to be on this small frame before adding more power.

I shared most of the motor info in an earlier post in this thread but a quick run down is:

Hemi block
Stock piston
+.020 ARC rod
ARC Standard Flywheel
NR 285 cam
Rtc8 non hemi head
Head decked .060
Stainless stock size valves
26lb springs
Titanium retainers
High groove keepers for more spring pressure
NR 1.2 roller tip rockers
22mm Mikuni kit on gas
Mongrel Clutch
F&B 3 Stage center exit if it fits

Should be a good runner for sure with over .300 lift and nice parts to keep it all together. I added some bracing to the block to help witn flex and pretty sure I will run it on race gas since its around 11:5:1 according to compression calculator.

Just waiting on my powdercoat guy now and for the extremely busy Karen to get to me on her list of seats. The frame and everything going on the bike is blasted and ready for powder. Just waiting on warmer weather but project is nearing completion. I will get some pictures of frame before powder and maybe assemble my wheels this week!

 

[MSPTREX]

Got the wheels mounted on the tires last night with all new hardware and bearings. Decided to use a paint marker and make some of the lettering white. I think it will look good with the retro theme. Just one coat with paint marker so far. Ill put on a few more coats so its more durable and get some shorter bolts for the sprocket wheel. Wheels look great mounted thanks to cambo61 for the burnishing!