Low revving MHR REP kit

[RiCkY70]

Hi guys,

i have full use of a dyno etc to set my bike up. when trying to set it up on the weekend i could not get it past 10000 rpm. in the malossi book it said it should be revving at 13000 rpm and all the other malossi mhr kits we have built in shop and fitted to bike are running around that.

i have been trying to set it up with out the help of other but im unsure ont his. when i did a run i could only get over 9.6 hp with heavy rollers. obvs with this kit were aiming for 13 - 14 hp but the revs are restricting it.

i was thinking it could be my cdi or the fact the rollers are to heavy ? they were around 6.6gram to 7.5 gram i tryed.

any help or info would be cool

the basic set up is:

piaggio L/C

mhr rep 70cc
yasuni r
dellorto 25mm
malossi viton inlet
polini primary gear up
polini 2g clutch
polini vari
stage6 drive face
polini kevlar belt
stage6 clutch bell
pm full circle crank
skf main bearings
polini 0044 air filter
stage6 v force reed block
polini 7.0g rollers


thanks ricky

 

[ma11b]

have you got the cdi unit?

i thought the standered unit would allow it to rev to around 13k anyway?
did you try lighter rollers

 

[RiCkY70]

got a tnt one. duno if its restricted or not though thats the thing.... and i was rused for time so dint have chance to try lighter rollers. but even with 6g rollers it should go to 11000 12000 rpm....

im guna get my inner roter kit on it and try it then. hopefully that will see me over 13

 

[TUUR]

MHR Replica kit isn't that high revving.
MHR Racing, MHR Team, Team2 could get close to 13k revolutions.
And going over 10000 rpm would also require another exhaust (Yasuni R's Powerband reaches it's top near 10000 rpm. MHR rep should aldo dead-end there.)

What variator are you exacly using? (only described as "Polini vari")

 

[tiba_karotsu]

the pipe & cylinder kit you're using will not allow you to make power above 10K rpm, the MHR Rep kit & Yasuni R exhaust are meant for street riding applications.

you need to do stuff to make it run above 10K rpm like port the current cylinder or change to an MHR cylinder & switch to a race oriented pipe like a C16.

 

[RiCkY70]

Hi guys,

Thanks for your info. with the combo i have. it should rev to 12000 13000 acording to malossi.

we have run bikes up on our dyno before with yassuni r pipes, mhr rep kits and have all been running at 12000 13000 rpm. we even had a few with zx pipes on which made 10000 rph but shit top end power.

from the bikes we ran up we have found the yasuni r makes more power then the c16 on a unmodded kit (ie no porting)
(i have a mhr team engine for that )

the bike is for day street riding but still with some power. 13bhp is the high end side of 70cc bikes hear in the uk. you only ever see a few road bikes set up well to make over that.

im thinking its down to roller weights which isnt letting it rev so high. so i will drop them and try it again. (with a new ignition kit)

ill upload the dyno graphs later for you to have a look at.

the variator im using is the polini speed control (6 roller) i will be changing to a yasuni c16 in the future but i think it should easy be running 12000 revs with the R. as the other bikes did.

thanks ricky.

 

[ipx]

six of 7 grams sounds too much , remove some of rollers

i dont mean disrespect but only an idiot dyno with rollers working cause you must dyno many times , every time with different rolller weight to find PEAK power rpm

correct way to dyno is to LOCK rollers in place ( i jam 2 rollers in one track ) now dyno it to find peak power rpm

then choose roller weight to target that rpm

 

[RiCkY70]

im not a dyno mechanic i only use the dyno when the shop is empty. i dont set up and run up other peoples bikes !

one of the mechanics did tell me to run it up with a fixed gear but i havent had chance to do it yet.

thanks for the adivce though. ill take that into account when im next using the dyno !