First build, hopefully fast.

[max350]

Got to ride it quite a bit today. It's 4 stroking almost all the time. New motor cleaned the ports, gasket matched intake and exhaust, high compression head, the rest is stock CG kit parts. Everything seems to work right just almost constant 4 stroking. i have tried every spot on the carb needle except full lean. Plug is stock but seems ok. Messed with the air screw a lot, seems to make no difference. I am going to start trying to read what i can find on hear, any suggestions where to start would be greatly appreciated. As far as the insulting posts I was not going to reply to the comments further, I have always felt if you argue with unintelligent people no one can tell the difference.

A good carburetor if you are replacing, is Dellorto 16:16 easy to set up

 

[Animatronicus]

Thatsdax.com sells a copy of the deltoro right? The RT? I have been wanting to order that one.

 

[Rudz]

Rutoung carburetor, I found mine for $20 shipped on eBay

 

[SpecializedMountainMoto]

Runtong is a copy of the 15.15, so its smaller than an actual 16.16

 

[Flyman]

Well it warmed to 37 degrees today & I went for my real first break in.It ran
better the more I ran it as I figured it would.Still a little fat, but for break in
that's good.

It pulled some hill,s with a little help peddling that I never thought it would.
I,m impressed so far.Some tuning & a better exhaust & intake & it will be just
as I want it.I have not even messed with ports yet.I,m not going to change
port timing just match & adjust my Fred head squish band & compression. I don't
want a high revving engine.Just strong tork for riding in hill country.

Fly

 

[LandSpeedRecord]

Thanks for all the tips everyone! My plans are to order a snake pipe and i do like the Dellorto carb. I am understanding the 4 stroking a lot better now and hope i can tune more of it out with the stock carb and modding the stock pipe untill I can get the better parts. I have high hopes for what I can get out of this CG with time, money, and work. I have some delusions of building my own carb from scratch but the Dellorto is a much better idea. I also have a variable expansion chamber in my head. Fly, it's good to hear about yours, I think this frame we are running puts the power down quite well. Mine is pulling up some steep hills even while 4 stroking and my 190 lb self on it with little to no peddaling help.

 

[Flyman]

Bud forget building a carb.Thats like reinventing the wheel, be leave me on
this one.Put you effort some where else.Now the adjustable exspanion chamber has
all ready been invented.I have one I used when I endro raced karts.They do
work but not as good as one would think.

I would be glad to take a pic of it & show you how it works.

Your Bud Fly

 

[Dave31]

If anyone reads my other posts it's about competing in a controlled track at the Bonneville Salt Flats.

I get bored at times with 20mph, so once in a while a few buddy's or by myself I will head down on to Musselman.

MB's are welcomed, fee depends on Charlies mood, could be $10, could be free, sometimes he wants $95 for four laps lol. http://mhcircuit.com/

We've had some great racing at MHC in the past. Wish i had the time and money to do another Death Race.

 

[LandSpeedRecord]

I have raced there once. Time Attack in an RX7. I think that track would be blast on a MB, it was the most challenging coarse I had ever driven in a race car though. They had recently layed down a surface spray that made it feel like driving on sticky oil for lack of a better description. I want to try it on the bike one day.

 

[LandSpeedRecord]

We built an intake manifold out of carbon fiber for the Fomula SAE car at the U of A. I had a few random carbon pieces laying that would have been a good start. Completly a silly use of time I agree, I just enjoy engineering fuel systems.

 

[Dan]

Nothing silly about it! Uber cool.

Would love to see your carb and wish I had the skills needed. A mass produced scooter moped does every thing we want but that's not the point. DIY baby! Gets the juices going and just more fun to ride what ya build.

Personally, I will be cheering you and the carb on!!! Do it. do it for the fun, the glory the keeps ya off the streets and out'a the bars. (LOL, wait thats me)

Every one would go nutz over a diy carb. Know I will. Just 2 cool......

 

[Flyman]

Hey I,m with Dan.Don't take my post wrong.If you can build a better carb
then can be bought, I say go for it.Even if it does not work out you tried.

All I was trying to say, was there is only so much time in a day.Working
combos out on engines takes time.Pipes lengths, compression ratos & so
on.Thats all.
Fly

 

[LandSpeedRecord]

Fly, I didnt take it wrong all, i know you guys would enjoy following and I would love to share building one. The more i think anout it the more likely i will give it a shot. I have a built in reed that i might try if I do also. I have more experience in throttle bodies and injection systems I have built for turbo cars but i dont want to take on building enough of an electrical system into this bike to run it yet. Part of what I love about this bike is the simplicity. And Fly you mentioned "a better carb than can bought" i plan on building "a carb" ha ha a better one is a tall order. I am actually kind of enchanted in the 6 volts this puts out and keep talking myself out of 12 volts for it.

 

[LandSpeedRecord]

Ok, I pulled the carb apart to understand it completely and check it over. Moved the needle to the leanest setting, completely removed the stock air box so just the filter element is there. Tried to gut the muffler but changing the pipe anyway so I gave up. Still 4 strokes with the end cap on the muffler even though I cut out the final tube, It restricts it a lot, I wiped it off at the motor end and blew thru it cap on and cap off and there is a huge difference. Any way I ran it cap off, it's loud as **** but no 4 stroking until very high rpm. A lot of low and mid power, there is a very steep hill near my house and it pulls up it extremely strong. Strong enough that I need to over build my back wheel when I have time. I am really anxious now to get the pipe, carb, intake, and probably around a 36 rear sprocket. Oh and good brake pads ha ha I keep forgetting I need to stop this thing.

 

[Flyman]

Dam man I really think you & I have esp going on.Same deal here.I pulled the
stock muffler to day, pulled the baffles out & welded a little longer lead in
pipe.Mine 4 cycles on top also.

I have to go to OKC this weekend & help a bud, so I can't work on mine till
Monday.I also need to change the brake pads, I have some new ones, just have not got around
to changing them.It is so funning reading your post, for it right down to the letter
as what I,m going threw.These bikes don't stop that good, when your going very
fast.I thought dang when I do get this thing running to where I know it can I
need to get it to stop much better,Ha, Ha.
Fly

 

[LandSpeedRecord]

Fly, I worked at Fair Wheel Bikes for 4 years and have some other industry hook ups as well. I am going to test some bake pads and get the bakes on this thing dialed in. I will gladly pass the results and savings on parts to you. We held the world record for the lightest usable road bike at 6.3lbs and it now has over 10k miles on it so it's the real thing not a show queen. With the port work and high compression head this thing is just out breathing the stock carb and pipe. To make real power and tune a two stroke, that snake pipe or a proper expansion chamber is a must. I want a light, fast, and fun motor bike so logic told me start with a light, fast, fun, bicycle lol. Its cool we met on this forum and get to share ideas and hopefully get to go ride together.

 

[Rudz]

Kool stop salmon pads

 

[LandSpeedRecord]

Kool stop makes some great pads. We have Mt Lemmon here and everybody hits close to 50 on the way down so brakes get a real work out. Thats on a lighter bike with no motor but still a lot of mass to slow at those speeds and 20 miles of it has them at full heat and stress for a long time.

 

[Dan]

I've never done an in depth study and always meant to ask. But I have found the cheapo pads that come with my cheap, big box store bike brake pads outlast the expensive LBS (local bike shop) pads I have bought.

Really, never took notes or kept track, so am asking. But does seem the cheap ones last longer but may be due to not stopping as well?


Next build, might try to do a study. Love doing that stuff.

 

[Rudz]

I think they're harder, they don't stop as well, but they last longer.

I killed my buddies pads when I rode his bike up in Big Bear Mountain, my other buddy had discs so he was fine.

I killed those pads though, lmfao