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Just judging by the displacement/rev range/mpg/power output of the stock Grom it seems to me that the factory cam profile is probably not very aggressive. We're all losing our minds over 1/32nd hp from poking holes in the airbox when there probably is real power to be made with a cam. Has anyone heard about anyone developing something like that? I'd be very interested.
 

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cams are only gonna be a big help with tunning, you can't control the power range yet an the problem you will have is not having the right amount of timming or fuel with the new cam.
 

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Granted my SSR 125 pit bike weighs about 50lbs less- but it will absolutely run off and leave my Grom. And it has an automatic clutch.
 

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Everything is a tradeoff, cam profile is no exception. HP potential is all about the head and how much (and how efficiently) it flows. The cam is, more or less, the mechanical brain in the cylinder head...pun not intended, but it works. With roller cams, the OEMs can use nearly the full potential of their stock motors. Honda does a damn good job balancing out valve events for good average power, efficiency and longevity. Thus, it may be possible to extract a little more peak power with just a cam change. However, average, a.k.a "under the curve" output will be nearly the same. Any seat-of-the-pants-dyno improvement(s) will be slight.


Expect maybe 2-4mph, at most, from a cam change, alone. There's a lot to match (compression, combustion chamber, port volume/configuration, induction, exhaust, displacement...and EFI mapping) to realize much more than that. The "Reader's Digest version"...give it a little more time, while the tuning pros work out the details and develop balanced packages that are "ready for primetime", a.k.a. for sale. The EFI and electronic speedo issues, alone, complicate tuning by a couple orders of magnitude beyond a carbureted setup.
 

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Outrider you have a great grasp on aspirated motors, did you stay at a Holiday Inn Express? Hahaha ...Respect Sir!!!
 
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Yuminashi is the only company working on one from what I know

I'm sure something from another bike fits right in there but it'll take us riders to figure it out , don't expect some company to go "hey btw this 30$ cam from a so-n-so engine fits the Grom"


Regarding the Yuminashi stuff - the previous info I got was that they are making 2 Camshafts - one for the standard head that will give 6.2mm Lift and one for their larger bore head SX30 - that will give 8.6mm lift

Apparantly the standard head does not have the room to give any more lift than this 6.2mm - It had been their plan to use the one developed for the SX30 head in the stock cylinder - but there was just no room - so they developed a second one

This is some of the reason for the delay - they have tested a prototype of the Yuminashi standard head CAM in Europe - it gave some improvements but the biggest improvement came when it was combined with the bigger 31mm throttle body and 150cc Light Bore, Light Bore Injector and K&N R1100, and Exhaust.

So they did not say this - but reading between the lines - I dont think that the CAM alone gave big changes on the standard head compared to the Honda one.

I am not sure what the standard lift on the valves is to compare the two above figures too.
 

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Regarding the Yuminashi stuff - the previous info I got was that they are making 2 Camshafts - one for the standard head that will give 6.2mm Lift and one for their larger bore head SX30 - that will give 8.6mm lift

Apparantly the standard head does not have the room to give any more lift than this 6.2mm - It had been their plan to use the one developed for the SX30 head in the stock cylinder - but there was just no room - so they developed a second one

This is some of the reason for the delay - they have tested a prototype of the Yuminashi standard head CAM in Europe - it gave some improvements but the biggest improvement came when it was combined with the bigger 31mm throttle body and 150cc Light Bore, Light Bore Injector and K&N R1100, and Exhaust.

So they did not say this - but reading between the lines - I dont think that the CAM alone gave big changes on the standard head compared to the Honda one.

I am not sure what the standard lift on the valves is to compare the two above figures to.
Simon,

Do you know if the Yuminashi SX30 head will come with this cam installed? It does not say that it comes with a cam at all on their website...
 

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Simon,

Do you know if the Yuminashi SX30 head will come with this cam installed? It does not say that it comes with a cam at all on their website...

I believe so - but not 100% sure - I think it is the complete head assembly - Valves / springs / rollers and CAM

Not sure when it will be released - despite being on sale for > 3 months!

I have the CAM for the Standard head on order - still waiting that too!
 

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I believe so - but not 100% sure - I think it is the complete head assembly - Valves / springs / rollers and CAM

Not sure when it will be released - despite being on sale for > 3 months!

I have the CAM for the Standard head on order - still waiting that too!
Is the Standard head the same as the SX30? If so, why did you order the cam?
 

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Is the Standard head the same as the SX30? If so, why did you order the cam?
No the SX30 head has additional machining done on the head, larger valves, reshaped combustion area and I assume reshaped CAM area

I believe its a base head modified.

I ordered the CAM to fit in my standard head 3+ months ago when I ordered the Light bore, Injector, Valve springs

The info on performance / lift / different CAM etc. came later after it was ordered and paid for - the CAM was initially supposed to be the same between the SX30 and standard head.

The SX30 head will be unpainted for greater cooling also.

I originally did not plan on buying the head - probably still wont.
 

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I'm happy to give my opinion :)
Power is gone mid range and is shifted up to 7or 8k rpm.
Not ideal and i would not recommend.
Valves also make a LOT of noise (i have to put the replacement springs in), valve clearance has been checked again.
I dont think i gained anything except being able to rev higher.

With 14tooth front sprocket i did 125kmh yesterday, but the ecu was still adjusting itself after i removed the db killer from the slipon


Sent from my iPhone using Tapatalk - now Free
 

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save your money and go with a big bore kit from the voice of expierience repacment cams are a joke for these motors,web cam,megacycle,any of em,best bang for buck is 150cc big bore bar none.:hondalogo:
 
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