Scooterotica

Timbo wrote:Can thoroughly reccomend the MB BGM Racetour 225. This is my first proper "kit" having run an unmatched Mugello for many years and previously gone down the rebore option. It's a no brainier unless your budget is tight or your old school.

Old school tune on yer cast barrel gives 'bang for bucks'. It's cheap and has room for rebores.

RT kit has forged piston, 1mm RIK rings, CNC head, alloy barrell, nicasil lined.....and good touring BHP out of the box. But it costs more than an old school tune.

Horses for courses.

Was the Mugello not a proper kit then?

I think one thing about mugellos compared to a diy tune is that if you read MBs tech pages the port timings can be hit and miss. I have no experience with mugellos, so its not my opinion, but I would think that if you are prepared to tune your own barrel at least the cost of doing so is far less than buying an expensive kit wit port timings that may not be perfect, which i would expect after paying 400 quid. as said, this is not from personal experience so dont hold me to it but have a read of MB's site with regard to this.

However, the mugello does have nikasil liner and much cleaner porting than a ally cheapo kit.
other things to consider; who is manufacturing these barrels and which is the best supplier? some of the ally kits have had soft iron liners (reportedly), and i know that on my sr kit, the cylinder head will need skimming to get a perfect squish; not ideal, but considering the price, not the end of the world. as for the pistons, no idea, i fitted an asso for piece of mind.
if you are happy to tune one (the ports will be rough as), then you could get great bang for buck and the pride of knowing you did it yourself, and should it go tits up you can i the meantime tune your iron barrel and have it as a spare.
which supplier were you thinking of using for one, and has anyone else had experience of getting one from said supplier?

I have worked on a couple of scooters lately that had cheapo ally kits on, they have both covered about 2000 miles and had running issues (not sure of supplier). (start get hot cut out, hard to start again until cool) We changed everything possible and at great expense (CDI, Staotr plates, Plugs, Leads) in the end i stripped one down and found that the piston/bore had 25thou clearance and i could get a whole set of feeler gauges in the gap. Confirmed that it was this causing the issue by fitting a home tuned iron barrel and it's still running 3 months later. Some diagnoses for the other kit as well. Another one I have worked on/built is still running ok after about 5k (supplied by Beedspeed).
As Olliwtf states some are made with soft liners and wear out really quickly, so you pays your money and take your chance.

I would have a go at doing it yourself on the iron barrel, gives you a sense of pride when it all works ok.

Great info and the idea of an 80, s type tune apeals to me asmits a w reg gp 200 I 2as kind off thinking about keeping the standard cylinder as a spare but I guess there cheap enough new if it went bang and I have the gts as a spare scooter anyone used thosethin 2 ring mahle pistons that scoot restos sell

I have a Mahler 2 ring piston in my 200 engine, fitted with 28mm PHBH and a Taffy copy. Goes well considering it was put together run in for 200 miles before setting off for Davos, a minor heat seize but runs well. I will be stripping down shortly to match the ports and clean it up, will port it slightly. Plan on timings of 170 exhaust, transfers are already 126 so just a tidy, 145-150 inlet timing.
Thinking of going reedvalve but might tune this way first then reed valve at a later date.

soosh wrote:Was the Mugello not a proper kit then?

Yes it is but I ran it for 4 or 5 years only to be told that the piston wasn't matched up properly...

Andy W wrote:I have a Mahler 2 ring piston in my 200 engine, fitted with 28mm PHBH and a Taffy copy. Goes well considering it was put together run in for 200 miles before setting off for Davos, a minor heat seize but runs well. I will be stripping down shortly to match the ports and clean it up, will port it slightly. Plan on timings of 170 exhaust, transfers are already 126 so just a tidy, 145-150 inlet timing.
Thinking of going reedvalve but might tune this way first then reed valve at a later date.

Im liking that I was thinking along those lines which reed are you thinking off ?

Shocky
I will port to the spec already mentioned first and then look to fit either a lth or Atomic (small one) reed valve kit. I just want to build something to carry me and the missus on for a bit of touring, but when I'm on my own that will have a decent turn of speed and a bit of fun. I have a fast road tuned Imola for fun, so this will be a sensible one ish!!
As built out of the box it makes 14.5bhp so hoping to raise that with a bit of sensible porting but still leave it easy to ride, as I said it took me to Davos and back with no major dramas which was nice considering it was brand new. I am now in the process of build the rest of the scooter to put it in to. My Imola is back in my race rep and being thrashed when ever I get the chance.