whats the first steps toward more performance

[Karl Snarl]

seems like getting a dirtbike exhaust might just be harder than getting a new one since there is no junkyard in my city do you have any off the shelf option ?

also what are your toughts on dio reeds ? do they even do anything ?

ebay is your friend. They have any dirt bike pipe you wanna find for the most part, new used, smashed, still in the box. I'd just go for a used one and fab it up from there. Just make sure it's for a small 2 stroke bike, not a 4 stroke.

reeds do help, I'm not a fan of the dio, hear they leak pretty easy. That An I normally don't need a reed that huge for the rpm range I build in. A G2 reed does all I need it to so far. More than plenty enough flow, and works even better if you print out a stuff, or buy one. I am super please I decided to try the G2 reed, really improves the bottom end and allows for way more duration for the midrange. You can use different pedals than me to get different responses. I build for low end and mid range power.

oh and the G2 makes it easier for me to mount the saw carbs I use. I use saw carbs for their ease of tuning and awesome performance. The models I use have been good up to 8k rpm's, which is where I draw the line as the max I will go with most of my builds. Usually I keep it below 7k rpm's. I say most, because this year I want a Minnelli hybrid.

 

[manuel newsom]

ive been looking at ebay but sadly here its a pretty small site and i cant find anything under 100€ and a banana exhaust from aliexpress is 25€ i know it might not be half as good but its probably good enough for the use i make of my bike

 

[Karl Snarl]

Get a mz65 fat belly, then cut the header off. Trim is down to about 5-6 inches. Then use a 1 1/8-1 1/2 j bend exhaust piece, and weld it in where it needs to be. I do two steps, the header to a 1", then 1" to the 1 1/2 j bend, to the expansion chamber on the mz65. I call it the KS65. Do a quick search on this site for KS65, it will show you what I did. It works really well, just adjust the header length to the rpm range you want to run in. I run low, so my header is a bit long.

I just mounted a headlamp to the front of this bike today. I'm done with it. I just need to clean up all the welds, and paint it. Then wrap the pipe with fiber wrap.

 

[Karl Snarl]

Nitropropane

That's interesting, you now have two base lines to work from with not much difference in temp a 50 degree spread so 16oz per gallon seems like it shouldn't be to much hotter than 12 but will give you another base line to work from, being half of the 32oz mix this just seems a logical next step...

motoredbikes.com

 

[manuel newsom]

Get a mz65 fat belly, then cut the header off. Trim is down to about 5-6 inches. Then use a 1 1/8-1 1/2 j bend exhaust piece, and weld it in where it needs to be. I do two steps, the header to a 1", then 1" to the 1 1/2 j bend, to the expansion chamber on the mz65. I call it the KS65. Do a quick search on this site for KS65, it will show you what I did. It works really well, just adjust the header length to the rpm range you want to run in. I run low, so my header is a bit long. View attachment 163576

I just mounted a headlamp to the front of this bike today. I'm done with it. I just need to clean up all the welds, and paint it. Then wrap the pipe with fiber wrap.

i found that on aliexpress it looks very similar to what you have is it the same as a mz65 ? its much cheaper and im on a pretty tight budget

 

[Karl Snarl]

i found that on aliexpress it looks very similar to what you have is it the same as a mz65 ? its much cheaper and im on a pretty tight budget

Even the smaller chamber will work better than stock. Just won't have as much of a kick. I think they call the fat belly a big Bertha. On my phone bout to head in to work. Or I'd look at you link. I check it out when I get to my PC.

 

[Jaycee604]

Get a dirt bike pipe, small 80cc ( I mod mz65's into the KS65, look on here in the search to see my work, lol, an I'm going to be working on a cr80 pipe soon ) works well, look up how to tune the pipe for what you want. It's just some math for length and width etc, not to hard since the chamber is already made for you. Do as chainlube said, and if it's not in the right zone, shave from the top of the jug how much it is off. Before doing that, make sure your piston uncovers the ports, if not, add gaskets till it does. then measure squish and set. a quick balanced crank is as easy as drill 6 holes the right depth at 12mm wide. I'm assuming you've already cleaned the ports. You can widen them if you want, but don't change the height, make them kinda football shaped. American football.

You have any pictures of a balanced CG crank ?66cc) some ppl just make a half inch hole 15mm deep on the crank weight lol

 

[Karl Snarl]

You have any pictures of a balanced CG crank ?66cc) some ppl just make a half inch hole 15mm deep on the crank weight lol

You do three 12mm holes,15mm deep on a 66cc for about a 45% balance factor. For a 100cc it's about 40%. One hole between already there holes and one on outside of each existing hole.

 

[DieselTech]

You have any pictures of a balanced CG crank ?66cc) some ppl just make a half inch hole 15mm deep on the crank weight lol

Here is what you want to see. Karl gave you the hole dimensions

 

[Greg58]

Here’s one I balanced, it’s a 38mm stroke engine.