Two Stroke Mini Bike

[Desertduler]

I am going to build a Mini Bike I have fond memories of the one I had as a kid, it was a little Kawasaki MB-1 Coyote with a dinky 50cc two stroke engine, I am either going to make a frame or buy one, this is going to be the engine that I will use on my Mini Bike. It is a Sachs SA290 engine which will not look like it does in the present state after I get through modifying it, the displacement of the engine is 293cc's it has about 19.5 hp @ 5500 rpm but that will change a little after I get through with it.

 

[2SlickNick]

Oh he!! Yes...

I can't wait for this. I like using a donor and modifying it.

 

[Desertduler]

Oh he!! Yes...

I can't wait for this. I like using a donor and modifying it.

It will be fun, I have a few of these engines, I will make my own expansion chamber for it also.

 

[Poboy kartman]

Ohhhhh.....yeah!

 

[landuse]

Nice! I look forward to this one!

 

[Desertduler]

A few facts about this old two stroke is that they have forged pistons and forged aluminium connecting rods and a full circle crank with all roller bearings, 19.5 - 20 hp @ 5500 and 19.5 ft lbs or torque @ 5000 rpm with a flat torque curve as on can see in the engine output graphs, I can easily make some more power with this old engine and I am going to modify the engine in a way as so it has more tractor like pulling power than high rpm power.

 

[chancer]

http://www.timeanddate.com/countdown/to?p0=1440&year=2016&month=5&day=1&hour=0&min=0&sec=0

62 days!

 

[Desertduler]

http://www.timeanddate.com/countdown/to?p0=1440&year=2016&month=5&day=1&hour=0&min=0&sec=0

62 days!

Yup, maybe sooner if I want to burn all my vacation or work to the end and have them pay me the vacation on one check I have the option of either, I am going to burn up some of my sick leave because on March 4 I am going to have surgery to repair a large Hiatal hernia that I received after a high speed crash during a motorcycle desert race that I was racing in, I want to get it done before I retire.

 

[landuse]

Yup, maybe sooner if I want to burn all my vacation or work to the end and have them pay me the vacation on one check I have the option of either, I am going to burn up some of my sick leave because on March 4 I am going to have surgery to repair a large Hiatal hernia that I received after a high speed crash during a motorcycle desert race that I was racing in, I want to get it done before I retire.

I had a hiatus hernia find 10 years ago. I want allowed to eat solid food for 2 weeks. Man, was that difficult. I lost about 10kg doing that

I hope it goes well

 

[Desertduler]

I have been putting up with mine for too long, it will flare up sometimes and it feels just like you are having a heart attack, I went to a specialist and he says I need to get it taken care of mine is of the dangerous kind and I have had it about 7 years and it has not bothered me a lot until now. When I crashed real hard my diaphragm muscle was torn and the doctors thought that it would heal and repair itself without surgery but it did not thus creating my current problem.

 

[Poboy kartman]

Good luck Brett.....

Keep us informed....Paul.....I just lost almost 5 kilos in the last couple of weeks with the flu and pneumonia....Doesn't sound like much...until you realize I'm 6' tall and only weigh about 145 now....10 lbs. is a lot to lose.

Not being able to eat sucks....thankfully, there's Boost which helps.

 

[Desertduler]

Thanks guys for the well wishes, I am sure that I will loose some weight too which will give all my toys a performance boost!

---------- Post added at 10:28 AM ---------- Previous post was at 09:58 AM ----------

This is the start of the race in which I was in that was a blast but I am paying for it now, I crashed real hard about 60 miles in to the race but I was able to finish it, now I have to pay the fiddler 7 years later.
https://www.youtube.com/watch?v=z2QBotStcVs

 

[itsid]

Wow, I was just about to drool onto the Sachs engine a bit...
And then OUCH..

Bret, good luck for the surgery and a fast recovery;
I'll keep my fingers crossed for you!

Oh and yes.. minibike... but health first!

'sid

 

[rushking19]

Sounds like a good build nice to see you with something new

 

[Desertduler]

Thanks guys! I will be back up to speed in no time, this will be a fun little build, I have some ideas that might be pretty cool I hope!

 

[chancer]

Hey... Maybe while the Doc is in there he can do a little porting and polishing...Add some roller bearings, Etc Etc. Boost your performance add a little free HP.

 

[Desertduler]

Hey... Maybe while the Doc is in there he can do a little porting and polishing...Add some roller bearings, Etc Etc. Boost your performance add a little free HP.

Lol, yeah, maybe a good tune up.

 

[NewbCarter]

Put a turbo on it

 

[Desertduler]

Put a turbo on it

No need to, this engine will have enough power even without any engine enhancements!

 

[Desertduler]

I have a brand new cylinder head (not that this engine needs one but I will use it) and I will do a little work to it, the spark plug hole is 18mm x 1.50 and I will make an aluminum bushing that will thread into the 18mm threads and the bushing will have 14 x 1.25 threads on the inside so as I can use the smaller plug and reduce the combustion chamber volume slightly and then I can use spark plugs that are easier to obtain than the old 18mm plugs, this engine does not use a head gasket, it uses the two sealing rings that are cast right in the head, I can also O-Ring this cylinder head too if I choose if need be, more on that later when I find out the squish band dimension.