TRK's weed whacker Razor dirt bike

[The Restore Kid]

Soooo the neighbor kid has had this thing since his mom got it last year for 10 bucks at a garage sale.. Batteries were shot so he just pushes it.. Since helping his dad with his barn, Troyboy always wants me to push the thing.. I always did think of how it needs one of these weed whacker motors..

Pushing the bike around finally sealed this deal.. :laugh:

 

[mrpat]

THIS is going to :thumbsup:be interesting

 

[The Restore Kid]

It doesn't look to be too big of an ordeal.. Plenty of space, not a bad looking rig.. It evidently has had a pretty major crash judging by these bars.. :laugh:

 

[Sinner70]

ok. im hooked.
subscribed.

 

[The Restore Kid]

After ripping the motor and batteries and extra parts out of the bike, I was able to mount one of these (Koritz???) weed whacker engines pretty well right in it.. I pushed the lower end up tight to the bottom frame rail, and made an aluminum plate that pinches the engine to the frame..

I was originally thinking of punching out the mounting screws and running bigger ones, but after running the bike some, I am sure these original small gastank screws will hold just fine, and any other one of this engine ( Koritz, Green Machine, McCulloch, and dozens of other labels ) will just bolt rite in in it's place..

 

[The Restore Kid]

FIRST thing ya always do with them, is cut off the original output tube exposing the crank shaft which is the output from the clutch.. Then you have to rig a sprocket or some kind of useable drive system instead of a square tube...

I have 35 chain one that uses this original super tiny chain, and this one will run 420 chain..

I found that a 10mm 1/4 if drive socket, slides rite on, and is real close to 1/2 OD.. I thought of using that as a hub, until I found a bushing that fits nice and snug... Always looking for the better way, i ended up deciding on the bushing.. I was able to press the bushing on, then use the engine as it's own lathe, and turned the bushing's OD to 1/2 inch plus one millionth.. To assure a good TIGHT press fit.. No welds needed..

 

[The Restore Kid]

If ya wanna run the throttle, you're gonna need a throttle cable... I had a set of grips and full throttle system from a China moped that was wrecked.. They worked out pretty sweet..

 

[The Restore Kid]

With a little two stroke, it will absolutely need a jackshaft to cut the rpms into a fraction, and multiply torque by buttloads.. I looked at flat mount bearings, I had some pillow blocks that weren't quite rite...

I need a standard damned tube with two bearings like anything else.. :glare:

OPE!!!! :laugh: Here we go... FINALLY a use for this MTD Trail Flight swing arm...

 

[The Restore Kid]

I cut it to length so I could stand it up on the original motor mount, like a tower..

after hackin it, and playing with stuff, I REALLY liked it like this better... SO I looked it over, knowing the pull of two chains, is going to try and twist the jackshaft out of the machine, so I did my best to figure where the chain is pulling towards, and madded a bracket to an upper frame rail, to keep the sprocket from pulling forward..

 

[The Restore Kid]

With an engine and jacksahft mount, there's no reason to not find gears, chains, bearings.... a setup... Best I could do, was a Honda 90 rear axle for a jackshaft.. It's damn near 5/8 main bore.. although I have AWESOME bearings that fit minibike OD, and this metric ID.. Then at the end, the bolt tapers to about 1/2 inch..

Boyyyyy I so liked this one piece, that I spent prolly 2 or 3 hours pissing with spacers and figuring everything out, all it needs is welded.. Too bad I have no welder.. :doah: WELL... I will some day want better, I might as well build a real deal... So I went with this long bent jackshaft I had. Once it's cut to length it's barely wobbly.. I will be able to spin this out of it when I use the "self made lathe" method to cut the one end to 1/2 inch bore..

 

[The Restore Kid]

Wowwwww.... Thats pretty damned close... Better stop with the hacksaw blade and move over to the file...

Files take forever, but hacksaws take huge bites, so there is a certain balance between the two..

 

[The Restore Kid]

Well, if I had a welder, I'd weld this sprocket on so I can move on... But who wants all that.. TRK being the retard he is, will just have to cut a 1/16 inch keyway with a hacksaw blade.. This should only take an hour and 350 put on the sprocket, eyeball, take off the sprocket.. :doah:

Now that theres a jackshaft, sprocket and keyway.. we just need a way to keep it all together.. I got no Key for it, a drill and tap will just try to screw itself off (left hand thread side)

HELL, I'll just drive this ring shanked drywall nail into the keyway... This will soon go from temp fit to permanent parts.. :laugh:

 

[The Restore Kid]

Sprockets chains and 13 weasel power

Well, I was able to use the original chain tensioner, just removed the original wheel and used a Sk8-Board wheel and bearings in it's place for the wheel side, found this large pretty light weight china dirt bike sprocket for the wheel...

Drive side I had this sprocket, and a temp chain tensioner, just a Sk8-board wheel mounted to angle aluminum and C-clamped to the foot peg.. This should give me an idea just how stupid fast this thing is gonna be.. That sprocket looks pretty small..

 

[The Restore Kid]

Tearups....

One day this spring, ole Troy Boy was on his bike, slamming on his breaks and doing the big drag marks on the dirt road thing that kids do... I came out and said

"WHAT are you doing now Boy, tearing it up? :glare:"

so now all shuffled around dirt / rocks / grass, done by a vehicle, are known as "tear-ups" :laugh: The kid is funny as hell for four..
.
.
.
.
So now that my gears are there, I went to do some tearups.. Boyyyyy I was WAYYYyyy off.. I was lookin at it thinking 40,000 rpms equals SHEEewewwwww.. at least 18 miles per hour

But it turns out to be about 4.... :shrug:

It will do doughnuts and standing on the rear frame, it wheelie walks awesome..

 

[The Restore Kid]

well, as long as everything seams to be (there) for the most part, I can move onto new gears and a better tensioner...

as it would turn out, this one piece of some old 1970 Schwinn Cantilever break arm, bolts down and fits like it belongs.. Made true, made to pivot, made of lightweight alumnum, I'm sold...

Made a new wheel from Sk8-Board wheel bearings and some rubber hose pressed over them.. Ad a spring and wallah..

 

[charliechaindrve]

how does that thing pull with a full load on it? ive got an identical weedeater motor that "id like to build simething with. good job on the build too!:thumbsup::thumbsup::thumbsup:

 

[The Restore Kid]

Now that the bike does more like 12 mph, and is all working pretty good, I straitened out the front end, and found a new break lever.. Best I had was an old Lee Chi MX vintage BMX bicycle parts in gold.. From like a 1984 Sky Way.. :doah: Seams like a waste, but it's not perfect, and totally useless sitting in a box.. :shrug:

 

[The Restore Kid]

how does that thing pull with a full load on it? ive got an identical weedeater motor that "id like to build simething with. good job on the build too!:thumbsup::thumbsup::thumbsup:

They pull about like you'd expect from a 23 CC two stroke.. :laugh: This bike does like maybe 12 or 15?? Never GPS'd it yet.. I know it will pull 140 but it's like maxed out.. It does OK doing several hundred circles in the driveway, cement circle drive slightly down hill, build rpms, hit the dirt road slightly up hill, start losing rpms.. But with the carb rite, and making power I can drive UP the road towards the dead end, which is a long slow slight uphill grade, drive all the way to the cops house and turn around at the top of the hill...

But level ground but soft yard / grass.. anything not hard, it won't pull you.. It is really more for a 40 pound kid..

I also have this one geared for about 5 and it pulls pretty good on solid ground..

I am planning on yanking the engine, screwing with porting and larger exhaust to be able to build more torque, and see what I got for stiffer clutch springs..

I believe Koritz actually builds the engines.. I've had dozens of them.. many many different names.. This one has an actual aluminum ID badge that says Koritz Corporation, made in japan.. And this one seams really well built.. Everything tight and clean..

Plus I can see Koritz shipping them into the US, then all the US companies put their name on it.. I know lots of (John Deere) and stuff like that, is actually BUILT BY, Koritz...

I can't fathom 38 US companies all building the same engine, then shipping them to japan, to an actual engine manufacturer..

 

[The Restore Kid]

I've ruined Troys bike

well, for the past year and a 1/2, the kid has pushed this thing around, I gotta push him on it.. The two neighbor kids take turns pushing it... He is just SOOOO ready for it to have an engine, tells me at least once a day..

" I'm gonna put a motor on my dirt bike.. :glare:

He's even got all the wires cut off and some smaller parts removed already..

Now that it has an engine, he doesn't wanna ride it.. :shrug:

Me and dad are looking at it with the body and stuff all on it, after i drive up on the thing, first time dad has seen it run.. Both of us urging Troy to try it, but he shys away..

SO, I said

" I can see him being afraid of the chain, and I don't like the idea of him driving it without one in place.. I'll go rig one"

SO...
.
.
.
Twenty minutes later we have this slap together unit.. Both pieces were aluminum jug shields from these old chainsaws that got junked.. I've formed the bottom already, and am looking to cover the sides and top...

[/QUOTE]

 

[The Restore Kid]

Now that Troy doesn't wanna drive it, and it's mostly a unit that I can jump on and drive, PLUS it is raining huge snow balls with perfect sunshine as Michigan does... I switched off to more pressing issues, like getting the wood stove fired up and my mess cleaned up...