My Mini-Bike or what ever creative name you can

[geldartb]

i've had this thing for a few years now. picked it up at a swap meet. was originally going for a go-kart but all the ones the people had for sale were way over priced and didn't even have engines so i got this figuring someday i could use the engine for a go-kart maybe.

it started it's life out as a mini chopper and when the front forks broke off one day when i was riding it got made into what you will see later.

this is what it was for a long time


the forks were only held on by 3 little flimsy tabs bent over the top and bottom of the spring. found that out when i took it apart. it broke apart where the forks bolted to the main frame.

since the turning radius sucked i shortened the forks when they broke off the front. same front tire but more mini bikish.

since it needed brakes bad and my cousin had a mountain bike headed to scrap i took the front forks.


been using it around the yard to get around..been wanting to fab up some sort of trailer hitch for it and since i got the cart it turned out ok.. just a rough setup for the hitch right now gonna fine tune that later. it's bolted to the frame so i can remove it when i want.





still tweaking the muffler setup but my plan was to have it exit away from my legs and back. the fittings were junk anyway so..gonna take another piece of the metal to take the place of the bungee cord. kind of like clamping the handle in between the two pieces.




and then the cart..found another 2 tires for cheap so i figured i would try duals in the back. seems to be working good so far. not sure if i want to do them in the front or not. in between the rims i used some thin wall pipe to give some stability.



as for the bike it's got a 60 tooth rear sprocket. not sure which way i want to try first higher count or lower count. the engines a little tired but it still moves. did a quick run and it went 25.9mph..

[Superdave]

Nice!


That's kind of how my son's took shape.. was an old 70's frame that would barely fit a 5 HP Flathead. We raked it out to 45 degrees using some stretched bike forks and angle iron from a bed frame to make the wheelie bars. It can pull/haul pretty well now.



planning on stretching it about 12" and widening the back to fit a 11" slick, then maybe a GX340 and a whole new front end and good brakes.

[geldartb]

Nice.. like the wheelie bar. never thought about that for mine but i was thinking about doing something like the rear pegs off a bmx bike on the rear.

yeah i've been thinking about a newer engine.on flatter land it could probably easily do 30mph.the 25.9 was with a slight upward incline and probably 400'. gotta check the clutch too and see the condition of that .the front end on mine may not stay but for the time being it fit the needs which was brakes since it had none before..

still planning out the exhaust. it didn't come with a stock muffler just a 90* piper that dumped under the seat.. been looking for a slightly bigger rear tire. the steer tire from a riding mower is nice but when i drive it in the woods down here it leaves a little to be desired for traction..

looking at something like this..


wouldn't mind stretching mine a little and coming up with a better position/angle for the seat..right now the whole thing is a little rough but once i finish welding and throw some paint on it she will look good. one thing though the orange forks gotta go. some other color is in the future.

it can pull a load pretty good. had the cart full of metal and it still did pretty good..was using the bike to haul stuff around yesterday. mostly small branches and some big ones broken down to fit in the cart..

[Superdave]

headers are easy to make for them.. lol


Here is the kart that i stretched and put a GX 390 on. This thing would probably tow my car..lol




You can kinda see the exhaust, it's made with a header flange, a 1.25" mandrel U bend and some scrap.. then a mini version of a Flowmaster 40 that i made.

[geldartb]

nice. i like the mini flowmaster. that kart is what i wanna end up with next.

i was initially gonna do two of the mufflers i have now but in the manner of keeping it simple for now i went with one. it's all 3/4" stuff from the engine through the muffler.

gotta pick up some more grinding discs and flapper sanding discs for the grinder so i can finish the pipe.

did a little work on the exhaust and aside from some header paint it's done. took one of the 45* fittings cut the male part of since all i wanted was the female threaded part and welded that on did some grinding and made it look more like one section of pipe.


i was looking at the air filter setups like you got on there but i don't know if it will get in my way since the air filter is right under my ass on this thing. might go for the k&n version of the stock filter.

[pocket-rocket]

I've got an old minibike of mine in the shed that I was going to rob the old 5hp Briggs off of to get my snow thrower going. I bought a used Honda just like what you guys have for $100 a couple winters ago and mounted that on the snow thrower instead. No idea what model the Honda is, but I can say I didn't get it out last year and with 2 year old gas with Sta-bil in it the thing fired up on the 2nd or 3rd pull. I was shocked I didn't have to screw with it. The carb is acting like it's plugged now, thought, but it is to be expected after 2 years...

Edit: it's GX160 on a snow thrower almost as old as I am. It was originally used on an Amishman's water pump and was only about 2 -3 years old when I got it.

Huh, Tapatalk is being stupid and will only let me have tapatalk host the pic instead of 60v6 and it won't upload to tapatalk...

[pocket-rocket]

Here's the go kart I want...

[Superdave]

Here is what i ended up doing with my son's exhaust, the 14" header was just too loud. So I made a quick adapter and bolted on the stock muffler from a GX340. A little chevy orange on the end for better visibility too, lol.


Still moves pretty good, engine is really tired though.

[geldartb]

nice setup. like you said they are real easy to build exhausts for..


as far as oil is concerned. what do these engines tend to favor the most. the manual says any high detergent premium motor oil in 10w40 weight. looks like from the chart temp range 10w30 would be good too. just didn't know if from your experience with these engines if they had a particular oil they liked better. just wondering if any 10w30-10w40 synthetic oil will do.

by googling honda 4 stroke oil which is the other oil it recommends i came up with a few posts talking about shell rotella 5w40 which walmart has for like $20 a jug.

[Superdave]

I've been building go karts and mini bikes most of my life.. i just use regular 10W30, nothing special.


In a racing application something better like Royal Purple would be a good idea but for normal use no need to get fancy.

[geldartb]

ok cool kinda what i figured anyway. got either kind of oil in the garage. still got a few cases of royal purple left over from when i won it in the contest they had a few years back. think i might have some regular stuff kicking around too.

not really a racing application but i do run it hard sometimes. forget what i used last year for oil think it was just something i had hanging around the garage.

[Superdave]

lol, i guess i shouldn't say much about oil. My 390 is knocking now.. need to pull it apart and figure out why... haha

[pocket-rocket]

The Amish guy I take home after work does small engine work on the side. Not to long ago he had a Honda that needed a new rod, ect. I should see if he still has any of the carnage left over from it.

Sent from my HTC One X using Tapatalk 2

[geldartb]

well given the oil that was in this thing when i changed it last year anything can't be worse. lol it was pretty black and had a heavy consistency to it.

it's time for an oil change anyway so i'm gonna see what walmart has for motorcycle oil tomorrow. through a little googling Honda GN4 4-Stroke Motor Oil equivalent i keep seeing shell rotella 5w40 mentioned. the manual talks about automotive oils with a service classification of SE or SF.. so from what i get from reading that is that it's either the honda 4cycle oil or any automotive oil that fits the requirements.

probably just get 10w30 since my lawn mower uses that and the temp range is good to 90*f ambient and to be honest if it's that hot i'm not that motivated to do anything let alone rid the bike. lol

EDIT
well it appears the SE or SF class of oil is an ancient spec from the 70's and early 80's..lol

[Superdave]

I found this floating in the oil, maybe an odd part of the governor but the engine chewed it up pretty good.

No damage that i can see though, going to put it back together tomorrow night and fire it up.