20.3 ain't shabby at all! My 218 was dyno'd at 22! Got a stock grom that is need of some tinkering...this kit is now all that more appealing.

 

Awesome numbers, just a smidge more than the FinBro 183 big valves

 

On the first run it made 19.23. That was with updating the trim levels for the last couple of weeks of riding. On the Dyno, it was way to much fuel without the benefit of the pod intake. I would like to hook up some forced air into the intake simulating the A/F ratio with all the fuel. I bet thats where the big HP #'s are derived from.

On the race track a couiple of weeks ago, I could flat out walk away from my buddies finbro 183 grom. I think he said his dynoed around 18-19. I expected to see a bigger larger gap.

 

Great numbers! My setup is the same intake/bore/exhaust/wb2/PCV and it pulls a 17/34 combo to 82mph GPS verified. Planning on getting the 34mm throttle body and dyno run again?

 

New TB? Yeah, I think I will down the line. My wife has a Grom that we have done all the same mods to. When I ride them back to back, Her's feels a lil more peppy...I will get that one on the Dyno soon. Fox, I have the 16/32 combo.

I will have the Dyno graph tomorrow and will post it up.

 

My Finbro 183 with stock airbox and Arrow exhaust system was Dynode at 15hp.

 

enhance the inlet airflow and you will see a power increase

 

I was running a open filter but the noise was a bit much plus my exhaust header is narrow so there is potential there. But I wish i had waited and got the 4v kit l.

 

What size is your throttle body? and your rev limit?

The official combination is Takegawa 34mm Throttle body + Takegawa Bomber Exhaust + FI-CON(ECU Plug-in) that can reach 22hp @ 8000~11000rpm

but I think 20hp is awesome enough for the stock crankshaft.

here is the link for the Throttle body
SPECIAL PARTS TAKEGAWA / ???????????????(???????4V+R?)

The Exhaust
SPECIAL PARTS TAKEGAWA / ????????( ????????)

 

TB+exhaust+controller=22HP

It's getting DEEP

sent from the batcave on the batphone

 

I have the Finbro Throttle body and stock rev limit. The dyno was reading 9250 when it cut out. My cam is the new Takegawa cam that cake with the 4V kit.

 

Finbro TB which is only opened up on the inlet side the butterfly is the same as stock and revs out at 12500.

 

Someone needs to flow test that 4v head

 

Takegawa do mean business when they design stuff. If they do a crank and a super clutch that will be crazy.

 

I got to ask, and I know there are others like me who can't leave good enough alone,
Has anyone thought about/planned on taking the 181 4v BBK giving it to someone like monkey father/finbro and then having them bore out the 181 cylinder head to accept an even larger piston such as the 198cc,212cc,218cc or 235cc piston from other finbro kits along with using the better crank/connecting rod from the finbro kit?

A nice reliable 26-28hp would be nice coming out of a 218cc 4v engine with all the beefed up internals like crank/rod/better bearings and finally maybe some port and polish work on the 4v head making each valve inlet/exhaust even bigger to flow more air fuel.

If i have thought it, i'm sure other like minded individuals have as well and hopefully its only a matter of time we can see some people on the forum with deeper pockets then me do something as described above. Grom tuning and modifying is constantly evolving.

 

Yes that is the plan as soon as one of the 4v heads becomes available separately. Being it koso, smr or take.

 

What I can't understand is why these engines don't make good power 181cc 4v making 22hp when you can get this sort of power from a takegawa 138 4v even a 124cc with a super head makes 15hp+ same as my Finbro 183 or is it just because it's fuel injected that's holding these big displacements back.

 

look at the guy with the carb kit that did a legit 90+ mph. I think you are right.. it think the fi is holding it back.

 

My 181's power falls off right after redline, I've wondered myself if the ecu pulls timing at that rpm or whether it was flow related.

 

to this point: ive wondered afew times why there isnt indexible cam timing gears available? would be nice to bump the cam timing 2 degrees see if it moved the power curve up. or for thos enot so rev happy, retard it a bit and really dial it in for torque gains.

 

I think when using takegawa 34
Will
Got more hp the finbro throttle body

 

im hard pressed to think you need a '34'mm throttle body on this small of a motor, (around 200cc) especially a 4 stroke. (the carbs are 28mm and they do fine). with that big of a TB, you are just slowing the velocity of the airflow in the TB. unless the heads can flow the same numbers all the way through the intake tract, its completely useless.

 

The intake port of the 4v is 28mm and slightly oval shaped (oval shape covered by insulator)

 

I had to hog out a Finbro "bored" intake and insulator from 25.5 to 28 just to port match, and honestly I would have liked to see another mm or two as the port is ovalized, but as you can see the insulator is paper thin where it supports the o ring.

 

If it's a butterfly tb it needs to be bigger to flow the same amount of air due to the throttle shaft and butterfly sticking into the flow path, correct? A slide carb doesn't have this problem with the exception of the needle.

 

I'd like to go carb on mine but not many have done it.

 

Fox85 is exactly correct. The throttle body needs to be bigger to make up for the throttle butterfly and throttle butterfly shaft.

 

Thinking of doing the slide carb from yoshi mjn28

 

bigger is NOT always better. 40mm? really? haha
id be hard pressed ot think this motor could use over a 30mm tb WITH ANY benefit aside from soembody saying ' i have a 34mm throttle body'

 

Fwiw a crf250 uses a 46mm tb from the factory