I want more acceleration - not top end - ideas??

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May 22, 2008
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Hi,

All the threads I come across seem to talk about top speed.

I want to get up to average speed faster.
I'm getting bored w/ the slow acceleration of my bike. - which is actually pretty good for a stock bike - no hesitation at all - but want more.

I want your ideas.

I live on a steep hill, so smaller sprocket is not an option.

Looking for the cool mods that worked that you want to share

Changing the air filter - pointed to the front for a ram air system?
read about beer can conversions - but didn't really cover what the changes did to the bike that much.

Best ideas for a muffler that helps acceleration w/out damage to a 2 stroke.
creating a glass pack type muffler - that has straight through exhaust but still has sufficient back pressure?
heard stories about packing the pipe w/ steel wool- but can't find it now.

Best idle pin location on the notches that may increase acceleration w/out over-leaning the motor? - mine is at 2nd to the top.

Read about the "bottle" - but never found any conclusive evidence that it actually works.

I know there are many individual threads that talk about different performance enhancements, but I have not been able to locate a complete -
step by step:
"how to increase your overall off the line performance" manual that covers all areas of performance enhancements.
A manual like this would let a builder know how well the different performance mods work when integrated together to create "one" - complete performance package.
That would be cool.

So throw out your best, and see if we can make one complete thread for this topic.

Thanks,

Troy Fitz.
 
actually, you said you dont want a "smaller sprocket" .....a smaller sprocket will give you more top-end, but will actually slow your acceleration.
what are you using now? if you're running a 44-tooth, switch out to a 48-tooth. you'll get up-to-speed quicker, and that'd be better for hill climbs.
the downside, is that your flat-out-wide-open top speed will drop a little.

i pulled the baffle out of the exhaust, my intake port was dremmeled, and my friend jay handmade an intake to fit a carb from an XR80. i gained a ton of acceleration with that combo. i have MAD power, and i'm running a 36-tooth

EDIT: what about a tuned pipe? look for andyinchville in the members list. they make them. he could give you a better idea about the performance benefits.
 
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gearing change -- starting point ?

what are you using now? if you're running a 44-tooth, switch out to a 48-tooth. you'll get up-to-speed quicker

carrot -- this was my first thought also
gearing down a little -- will get you to speed much faster
but - as you know - to be taken into account
you will lose a little of your top end speed

before making or thinking about a lot of other changes
this for me anyway -- would be my starting point

ride that MB thing
 
Hi,

Shave the head to raise compression....this is a nearly free way (if you have the materials to do it with) or low cost method to raise power....A tuned pipe will help also but it is more expensive....

Hope this helps.

Andrew
 
Great idea about shaving the head!

Don't know why I didn't think of that. I had the heads resurfaced on my REX, So it should work the same way on the bike.

I assume any machine shop should be able to do this.
Any changes in the octane? - since basically it's raising the compression.
I had read that higher octane is a waste of money for a stock 2 stroke.
I have been running 85 octane - think I should increase that?

What about the spark plug? - It would run hotter, so is a shorter plug in order now? - or not enough to really make a difference?

Yeah, got the gearing a little mixed up -

top speed - smaller 36

acceleration - larger - 48

got it.

I am working on a side mounted air cleaner that would get direct air.
Pretty excited about how it will work - and look. I am using an extra chrome breather cap I had that didn't work on my 5.0 engine.
I'll show pic's when closer to the completion.

"spunout"

"i pulled the baffle out of the exhaust, my intake port was dremmeled, and my friend jay handmade an intake to fit a carb from an XR80. i gained a ton of acceleration with that combo. i have MAD power, and i'm running a 36-tooth"

Wow! - I am intrigued! - questions.
OK - so did you basically just do a match port to the intake tube and head?
I noticed they were very different. I would think getting better air flow w/out all that turbulence would make a huge difference.

Regarding the custom intake - that is exactly what I was looking at, but I was not sure if it was too long it would negatively effect the performance gain i was looking for.
I wanted to have it bend at a 45 degree angle to create more of a side draft set up - direct air. Which to me would equate to providing more air mass, less heat, and greater power - if done right.

When pulling out the baffle, I have heard bad things can occur. The motor needs the back pressure to operate w/out eventually burning up. Have you taken any precautions, or have you not had any problems with it?
That's why I was looking for the thread on the steel wool muffler.

Any pic's would be appreciated.

thanks for the feedback so far.

Have some good ideas, but wanna see what else is out there.

Troy Fitz.
 
Before you go to "major surgery", shaving heads etc, try these first,

1. Electrics
Change copper plug lead with a better quality copper lead.
Change Spark plug, NGK B6HS, Gap .025" as a base starting point
Plug Cap, NGK has a better qulaity plug cap

My personal bike does not have kill switches, I simply stall the bike or use the choke, but that's a personal choice.
Change Magneto to CDI wire crimps with quality crimps and use solder.
My persoanl bike has no crimps, soldered all in 1, personal choice.
-----
2. Exhaust.
Make exhaust gasket the same shape as the engine's exhaust port.
----
3. Carby.
Same, make the gaskets the same shape as the inlet port where the "manifold" joins onto the inlet port.
Seal the carby where the clamp goes on, with oil resistant plumbers thread tape, seal the thread tape with hard setting gasket stuff, and place the clamp back on after it has set. This limits the air leak due to the way it's made.
----
4. Fuel
95 octane....., we have here 92,95,98.
----
5a. Oil mix.
??? your choice, but use hight quality 2-stroke oil. It's trial by trial.
5b. ratios
20:1, 25:1, 30:1, 32:1
 
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to - CARROT THE DESTROYER
I was just checking back to see all of the comments to your thread
man -- good stuff comes in very fast on this site

so as not to get -- far ahead of yourself -- I would

take into account BOLT'S recommendations first -------- #1
why spin your gears -- if you know what I mean
I believe what BOLT'S trying to do here is
help you with the basic known (weak points) known to your set up -- engine

once we get the basics down -- then we may move on
ya - easy for me to tell you all about it - but - admitted - not my strong point
but - one day at a time - working on it - as I

ride that MB thing
 
when milling the head that much it is going to up the compresion quit a bit.possibly causing detination or a ping. higher octane fuel is in order as well as a cooler spark plug. 85 octane go to 91, ngk b5hs go to ngk b7hs.
 
when milling the head that much it is going to up the compresion quit a bit.possibly causing detination or a ping. higher octane fuel is in order as well as a cooler spark plug. 85 octane go to 91, ngk b5hs go to ngk b7hs.

I had a head milled .030

the results were NOT good.

granted, it ran much stronger......but the added power also added more vibration. On the 1st & only ride, crazy things vibrated loose.....engine studs....the small gear on the crankshaft (right side), mangling the key & the keyway slot on the crankshaft.
IMO.....you can't really beef up these chinese engines.
they are, what they are.
stick with larger sprockets for lower gearing & you'll be okay.

my $0.02
 
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