mugello 225, only 12bhp so whats the solution

[cezeta]

scooter centre catalogue recomends a 60mm stroke crank to sort out the mugello 225 odd port timings.

im happy to do this but what kind of power can be expected. as always i would like a thumpy grunty flat power curve. i dont need peaks.

would a 62mm be a better option or would it throw the ports out even more?

[soosh]

Mate,i dont worry what the dyno says anymore,what its like on the road is more important.

[paul213]

I had some probs with my v1 kit and ended up with fettling it
exh 179 44.6 wide but nice oval shape
inlet 153
tran 124
std sx200 gearing
with a 30mm del and taffy pipe it got 17bhp and 17 ft/lb on readspeed dyno .
on the road its great pulls like a train really nice to ride but would just like another 500 or so rpm
I dont want to lift the exh port any more so am thinking of trying a devtour pipe .
before the porting it was flat as a witches t*t no power and no revs .

Paul

[cezeta]

soosh....they are utter rubbish on the road.

17/17 sound perfect. i do like riding it as i cane it everywhere and there are no suprises so more of what it does will be fine

i got some feedback today that 15bhp out of the box with a 25mm delorto and clubmant was achieved using a 60mm crank and a base packer so with a fettle it should work well.

replay have had 22bhp from them too using a packer and recessed head like the rt

id rather have an rt barrel but ive got this and cant see anyone giving me 500 for it......though im open to offers

[eibargum]

Had my 200 muggy V2, dyno,d at chiselspeed when i had a 60mm crank in and clubman and it showed 14.6bhp, i,ve a mate with a 225 and 58mm crank that had a bit of porting work done at chiselspeed and that produces 19 bhp with a JL3 on, and its nice and rideable, maybe send it to them or camlam to sort it.

[cezeta]

i ll be taking it up to replay at some point and let chaulky fix it. im just trying to not dump him with an impossible task.

i tried a jl3 and a kegra race pipe and both gave good power but you can still feel that its struggling to breath and even with the 9000rpm kegra it would not rev past 7200 and that felt like over rev rather than real ones the barrel should not really be sold if its that bad

ive got a b race pipe to try yet. its a grunty pipe so may suite it better and produce a dumper truck motor so ill just need a 32 tooth front spocket to get the gearing right

[Avantone]

It would be worth checking the port timings to see where you are. I recently fitted a 186 that had ridiculous timings on a stock casing and crank - way too short on the transfers particularly.

I ended up with a 3mm spacer, a 3mm recessed head and a shortened piston skirt to get the timings more reasonable!

[chris2470]

Just out of interest what timings would you suggest, something in the region of:
Exhaust 175°
Trans 125°
Inlet 150°
I've got a old 200 block that I may fettle with and I come up with these, anybody know if these will work OK to get a nice sensible level of tune coupled to a JL3.

[Avantone]

Just out of interest what timings would you suggest, something in the region of:
Exhaust 175°
Trans 125°
Inlet 150°
I've got a old 200 block that I may fettle with and I come up with these, anybody know if these will work OK to get a nice sensible level of tune coupled to a JL3.

I've used very similar before on a 200 and went it great (155/124/175@70%)

[chris2470]

Cheers for that , I wasn't too far off then.
I know the exhaust can be opened up to 65 or 70% of dia, with some quality jap rings but what is the optimum ratio for the transfers, ie 25% of dia for each side, or as wide as possible with as many as possible ground into the bore such as 2 or 3 extras boost ports.