Extreme Tune Up!!!!

[jeffspeeder]

i was thinking i know these have a limit to the modifications and the bike has a limit to how much the back rim can take. what if someone could make a stroker kit and a bore kit? and get a good 12 grade back rim and weld the sprocket of your choice to the rim its gotta be possibe a higher cfi carb more gas like raceing fuel? bigger exaust kinda like mine. i mean like if it could get over 5hp that would be awsome i mean some of you gotta agree that these little motors could at least use a little more power right? i got a bigger carb that would fit these motors but exactly how much would a carb change it self do would it help alot or not?

if anyone has any ideas or comments about this please say so cuz i think its a brillant idea but it would certinally take some work. it must be accomplished in motorbike history.

 

[nms]

As a general rule these motors cannot be bored - they are "flash chrome plated". What that means is that basically an attempt at boring them will destroy the motor.

As others have pointed out in past threads with topics similar to this one, these little engines are not really designed to be high performance - they are workhorse motors for Chinese people who need to get around.

Shouldn't this be in the performance section?

 

[JosephGarcia]

I agree, these engines were not meant to do that much, just pull someone around at a modest speed.

Just buy a motorcycle, or that "super go-kart" thing your so excited about in MySpace bulitens

 

[gone_fishin]

yeah, if you read anyone's early posts, including my own, you'll see we get so excited we just gotta tweak 'em...but, alas, they're basically un-tweakable. what you can do is optimize intake, combustion, & exhaust. that doesn't give us much to have fun with, but we do our best, eh guys?

 

[jeffspeeder]

ya i guess its fast enough i will admit it gets me somewhare at least

and that SUPER GO CART in my bullitens is something i want to build 20hp on a hand built small cart but the bad thing is i dont have to money to build it but hey at least i got a motor bike. YAAAA

 

[Bill Snow]

I know next to nothing about souping up a 2cycle engine but Dennis at Golden Eagle Bicycles Motors does.

The Last I talked to him he was getting 57 mph out of a 25cc engine. I didn't ask about any of the details but he did say just adding exernal items didn't do much. Internal work along with external performance modifications can make them a hot little machine. The catch is, the mods have to keep the engine as a whole in balance such as the right exhaust or expansion chamber, the right back pressure for one thing is important I am told. Dennis seems pretty sharp, I was told he used to race 2cycle motorcycles. One thing I should add here: He does not sell the souped up 57 mph engine

Dennis is using a different make engine than the Chinese engines we are talking about, so as stated, " they maybe good just as a basic workhorse".

Another thing I am told, after you get some miles on the engine and well broken in, it will open up and perform much better than when new.

I had canard designed ultralight airplane called a Falcon with a newly rebuilt rotax 2cycle engine. After I finished the breakin procedure and put a few hours on it I was brain washed into putting a certain additive in the engine. Most additives I hear are not worth the container they are put in, but I gave it a try. It was called "Slick 50" but was formulated for 2cycle engines. After following their directions I took it out for a flight to see if there was any change in performance. I found myself pulling the steepest climb out I had ever expierenced. All I saw was clouds. Man did that little plane feel hot and that was without a prop change. It did great until one day I had an inflight engine failure due to a seal leak that had developed. I don't know if the Slick 50 had anything with the seal leak, but like many others, I was interested in improving efficiency and performance.

I don't know if that would do anything for these little engines or even if Slick 50 makes the 2cycle stuff any more. I have also read reports that Slick 50 is not what it's cracked up to be and a waste of money.

Well, whatever, the experience was an eye opener for me. Both of them.

 

[Guest]

jeff- after wracking up a total of 35 miles or so, I will say this....I don't want any more speed from mine. I felt/saw my bike flex and tweak in ways I'm sure bikes are not supposed to. I don't think I could ever pedal a bike upto 35 mph, much less run mile after mile like that. It's rough enough on the bikes with the whopping 2 hp they make now.

I do know if I want my bike to last at least the summer, I will run it easy and pray the frame and rims hold up.

I will say I reached down and put my hand on the engine @ 30+ mph and it was nearly vibration free. The rest of the bike was a different story!

 

[jeffspeeder]

i will say if this is all we can do to these motors ive probley done just about all of it execpt a carb change heres my upgrades. brand new E3 dimond fire spark (big difference in performence) 91 octane, new muffler (which i found out since i put the new muffler on my motor has been begging for higher octane it runs real good on higher) better air flow intake, high performence oil. and a not so heavy jeff. which probley all that boosts me up to a sexy 49 mph WOW!!!! much satisfying for me. for all i know it could have more speed under its belt. it i get myself a 32t sprocket oooooo baby!!!


BTW im still running a 44t sprocket.

"MBc EDIT - This post contains information or advice that MotoredBikes.com knows to be incorrect."

 

[rcjunkie]

"MBc EDIT - This post contained content that is listed in the MotoredBikes.com rules as unacceptable."

Increasing octane will not improve performance one bit with an engine that has a 6.6:1 compression ratio. Please repeat this previous sentence outloud 50x so it can register in your memory bank.

Reducing backpressure over stock exhaust will, do some extent, improve performance, but the best exhaust modification to improve performance is a tuned pipe with an expansion chamber.

Regarding Slick 50, there is no 2 stroke slick 50 product on their website so you'll have to be more specific as to what you put in your Rotax engine. A smart aviator knows not to add any manufacturer unapproved products into their engine. I suspect that the performance difference you felt was a placebo effect at worst or slightly increase in engine power, not from the Slick 50, but from decreased density altitude the day you flew. If you put their automotive slick 50 product, you just contaminated the innards of your engine with PFTE which is the "active" snake oil ingredient in Slick 50. PFTE is basically minute teflon particles that is a Dow Chemical registered trade product. Dow chemical does not approve the use of their PFTE product in internal combustion engines. Tribologists have already confirmed that slick 50 is harmful because it can cause deposit accumulation in oil galleys and possibly clog high quality oil filters. I've been a pilot since 1991 and have many hours in a variety of piston and turbine aircraft and ask that you please stick to manufacturer recommendations. Its not ok if you hurt someone on the ground becasue of an engine failure.

Our engines will never be powerhouses. The reason is simple, they are very inefficient and one of the reason is due to the lack of a reed valve equipped intake system among other things.

 

[jeffspeeder]

ok your right then rcjunkie, i was just trying to say i run higher octane now come on i can if i want. i like my bike how it is you like your bike how it is. i like my new muffler which works perfect for it. try it and youll see. ok can we just end this arguement rcjunkie.

ok back to what we were talking about