Flywheel

[pingpong]

Can someone show me stap by step instructions with pictures on how to lighten your flywheel? Thanks

[blah]

Once you lighten it what if you don't like it? if you lighten your flywheel you enable the engine to rev up quicker than it normally would but you do lose torque. Flywheel weight is very important in getting off the line on these clutched engines, basicly the momentum from the flywheel weight helps to keep the motor spinning when the clutch engages. If you lighten the flywheel you may even get more "bogging down" depends on a lot of factors. To make this short as possible can i just suggest you buy a lightened flywheel and keep the original one handy. Back in my enduro days we used to add metal plates to our flywheels to get a wider powerband from our motorcross engines, wha? add weight?? :) ADA has a nice CNC'd flywheel ~$30

[pingpong]

Thanks I didn't know it would slow it down. So wat about new springs? Do they help any?

[blah]

I didn't say it WOULD i said it COULD but it all depends on a lot of factors, main one being how heavy you are.

Do new clutch springs help what? what are you trying to achieve? what's it on, what's been done, why am i here, why arn't i in the shed working on my bikes? arghhhh

**attention**** blah has just left the building.

[pingpong]

Hmm so I guess i won't be trying this mod but does anyone have a lot of free/cheap mods to do since I'm bored? I saw one that said to take off the washer from the spark plug... anyone know something about that?

[blah]

Bah, If you are bored then put your motor back together and go for a blat. The washer is there to for a seal between the head and the plug, if you don't want it to seal then take it off, wont give you any more power though. In fact over time im sure the sealing area on the head will get damaged. Also because the aluminium head heats up quicker and expands more than the steel sparkplug this will also cause further damage to the sealing area, the washer is normaly a good buffer to protect from this.

ok, in short DON'T DO IT

Now the washers about 1.2 mm thick when squished, so that's a 1.2mm length of 14mm thread sticking in the bore,
(14 /20)*(14/20)*pi *0.012 = ~0.018cc change in combustion chamber volume, lol.

so lets say, a 47cc engine and 8:1 CR would have a combustion chamber volume of 6.714cc = 8.000:1 exactlyish now if we remove 0.018cc then it's compression ratio would become

(6.696+47)/6.696 = 8.019:1 lol

Now consider this, the extra 1.2mm sticking in the bore would collect a bucket load of carbon all over the thread and when the plug is taken out it will surely stuff the thread in the head.

So, removing the spark plug washer will:
A. Stuff the head sealing area
B. Stuff the Head Thread
C. raise Compression Ratio by almost ZERO
D. gain exactly ZERO extra power

[blah]

whoops, should have been .185cc and 8.199:1 , so it made .2 of a compression ratio, still not worth the risk.

[zameil]

Chop every second fin off the flywheel and grind them down. But as Blah said you will lose some momentum with this mod.
Some of the guys over here are taking all the fins off completely. They don't idle their bikes for any longer than 30 seconds.

Blah, I'll get your pistons next week for you :cool:

www.pbr.8k.com

[blah]

Cheers zameil, no rush.

If you do end up chopping some fins off, it would definately reduce the power sucking air drag, probably out weigh any loss of momentum. Concentrate on keeping it even and balance it afterwoods on a set of blades or something like this:

http://www.shark-racing.com/Imagens/Balanceador/BalancJT02.jpg

Heaps of 2-stroke tech at sharkracing

http://www.shark-racing.com/Ingles/Tecnica/Tecnicaing.htm

[datalorr]

chopping fins off........ if you are going to go this route, might i suggest changing the colour of your barrel, if you can find somewhere that does anodizing great get them to do it black, not gloss, matt or satin it will help with cooling, a black surface disperses heat quicker also change you spark plug to a cooler one if you cant get it coated then high temp spray paint works just as well, it works trust me,


also looks cool

[pingpong]

thanks for all the help any other mods I can do to increase performance?