My mods and my max. RPMs

Alright, so over the weekend my friend and I installed some mods on my cag:

We bored the carb to almost 15mm, TT needle at 3rd position, Adj. main jet, rocket key, velocity stack and filter, and fiberglass reed.

We slapped the GPT tach on it today and it spun to 10,400. I just have some questions..First, whats the stock max RPM on a cag, I don't even know. Second, should I be spinning at a higher RPM with the mods I've done? Tomorrow we're taking the stock muffler off and cutting the header and adding some belly. Should I move the TT needle to a higer or lower spot? I wanna keep adding top end to my bike, I got pretty good accel. for the moment.

Not bad. I got 10,700 from a no mark 39cc jug, ported carb, TT needle at 3rd position, Adj. main jet (no adjuster), stock air box, exhaust port work, no base gasket, and CF reed.

Not the fastest but the low end really improved. Now I can get out of the corners and hang with guys 40 lbs less than me.

where did you get the gpt tach at and how much was it? if you dont have bigbore piston you can get about 14,000 rpm out of that motor

10,400 is great with the rocket key, take it out and you will see 300-600 more RPM out of it. The rocket key seems to make it more responsive on the low end but it kills the RPMs up top.

I thought that key was supposed to add 2 mph, which would give me more RPMs, hmm...I'll try it out. The modded stock pipe should be on sometime this week, let's hope that helps.

The tach came from midsouthminimoto

2MPH, right, outside of porting nothing out there adds 2mph that I know of yet except the Pro-line reed kit, if you believe those claims than buy the Ebay poop pipe that adds 6-10MPH. Sorry to come off like that but seriously these companies that advertise that stuff should fall under the false advertising laws and be shut down.

They should but life isn't always fair, just like slapping a 49cc sticker on a cag. And I stay away from the ebay pipes, thank you very much.

carb ki9ts with intake add 4 mph easy. you just have to know how to tune...

did you order your tach off the internet, cause i can't find it on the site.

thats funny cause taking off my air filter gained 3 mph

all that says is your bike was running way to rich thats why when you took air filter off you gaind hp

Tuning your bike can get you 10mph if it runs that crappy at first. I am talking about all the bolt on parts so quit being a smarta$$, oh yeah I have a radar gun and several tachometers at the shop and try new products all the time and have tested more products out there than only a handful of people, how do you measure your speed gains? Don't answer that, it is a moot point to talk to someone who did not realize how rich their bike was running to begin with. Hey I have some killer spark plugs that work awesome with bikes that run with no air filters, they are only like $500 but will give you 25mph. Next time you want to dispute someone with lots of experience and calibrated test equipment make sure you are ready to back it up and have the credentials. We are trying to actually help people with answers that are real and not some advertized magical gains, not everyone has a shop like me and an opportunity to purchase test equipment and one of each all the products out there, I have done that and now I am offering help and reviews of the products at no charge to help you guys make an educated decision not based on hype in ads.

lmao @ bartw i feel the same way but some people here dont have a clue how to tune a 2 stroke engine! hey bart that psws racing reed box kicks as$ i noticed i have an air leak around pulse tap at reed manifold i am thinking that a little loktite will seal her up! i hope the smartas$ quote was not directed towards me

I quoted the person it was aimed at. I don't mean to be rude but this is not a BS forum but rather a technical one and to recommend that people run without a air filter is just not a good idea and neither is the gains he claims unless his bike was out of tune or his filter was clogged.

don't get you panties in a twist. The stock air filter is VERY restrictive. so i eliminated it.I bet you money that you can tune your bike to run perfect with the stock air filter and when you take the air filter off IT WILL GAIN POWER. i look at the my plug before and after every mod i do. All those crappy filters out there are better but still not as good as no air filter. I know a thing or two about making power. I drive a ten second car to work everyday with A/C and a very nice stereo that i put minimal $$$ into.
BTW i use a GPT tach to measure all my mods. What "calibrated equipment" do you use on these bikes?

actually most of the V-stacks out there is the problem because they do not sit tight up against the bore of the carb and create turbulence instead of the velocity that they are designed to. I don't mean to be rude I was just a little frustrated with such a short answer trying to dispell the truth that I was saying about advertising that is found with most of these products. I use a radar gun, several tachometers and I still have some access to a flow bench at a company that I used to work for at which I ran the flow bench and calibration. I do my tests typically back to back or as soon as possible so that weather is not a factor with the same riders and before I knock a product down I try it on several bikes with different configurations, some people were frustrated when it would take me two weeks before I gave an opinion on a product but that is how long it takes me sometimes to try it on 5 different bikes with different setups before I give the best informed opinion that I can. It is not likely that you will find my posts talking about something that I did not try or speculating, if I did not try it I state that I am quoting someone else's opinion. Most people just do not understand air flow at all but I ran a flow bench and can tell you that on the fuel injected cars with mass air I could make the computer run 10% rich by just sliding the filter further onto the meter than it was supposed because it would change where the air came across the meter but not the volume. Anyway I don't recommend running with no air filter at all since debri will get in there and some of the filters do flow nearly as well as no filter but I cannot advertise which one is the best on here but I think that people already know and it has been discussed before. I sure know that from my description above you know which style "V-stacks that give you 100mph" to stay away from. Next time I am at my old shop I will flow these things and get a printout that no one can dispute.

Stock cag 7800 rpms.If your lucky.

Is that true a rocket key kills the topend

7800 RPMS!??! I thought they rev up to 9-9.5K stock....wow 7800 thats about 5000 rpms away from were im at right now, thats insane...
John

My stock Cag (no stamp head FF) tops out at 9,600K. Never tuned it as far as needle pos. or jetting so maybe I can get a lil more out of it.

Whats frustating is that my Open Cag only gets 10,800K. It does need to be tuned and I found a leak at the reed spacer (fuel leaking). I remember snowboard having nearly the same setup and hitting 12K to 13K if im not mistaken. Let me know if any of you see a problem with my setup?

mm64 ported head w/ boost port
NWmini CF reed (2 petal and old)
3 mm reed spacer
Stock ported carb
72 jet
TT needle at pos. 3
no filter (no room for one with my pipe)
Rocket key (might be from a midbike but dont know)
Blata Elite 11 pipe
1 piston ring ontop (dont ask why) thought it was worth a shot when I renuilt my top-end
mm64 indexed piston

I use a mini-mychron tach thats good to 20K RPM.


Please advise, thanks