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Post by rab on Apr 14, 2014 18:38:57 GMT
ok wich would be the best a cast top end or ally and why
even though ive re done the molossi on mine im still not happy with it and im thinking of going down the dr 177 kit route. there is 2 types out there cast and ally i can see ally being a good idea as it cools quicker and on an air cooled engine in summer i can see the advantage. but the cast one would seem a better option as it can tolerate higher temps so less likley to die in the event of the engine getting too hot any body care to shed some light on if my thinking on this is on the right lines ?
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Post by sbwnik on Apr 14, 2014 20:03:51 GMT
Have you done the porting on the Malossi? If so, then you're a bit buggered if trying to fit something with smaller transfer ports, and IIRC the DR isn't easily modifiable to suit altered casings.
What's up with the Malossi?
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Post by rab on Apr 14, 2014 20:41:09 GMT
i havent seen what lies beneath the barrel for my self as i had to get someone else to fit the new rings because i did not have time with work. with the power it has through 3rd and 4th and the fact its happy to cruise at 60 all day with more to give id say the porting has been done.and have been told it was all done at scooterrotica. i did get the dyno readout when i got the scoot and it was 13.2 bhp. so may look like im stuck with it i just hate the rattle the molossi has . the ring size was checked and replaced acordingly new bearing and gaskets new plug everything inside the head was replaced and cleaned the only thing that wasent changed was the piston wich is in good condition so i cant understand why it has the rattle and its annoying the sh*te out of me
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Post by sbwnik on Apr 14, 2014 20:47:44 GMT
What kind of rattle is it? Is it constant or just at certain times?
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Post by rab on Apr 14, 2014 21:18:21 GMT
just when cold and then just at low revs sounds like piston slap as the power goes up the rattle stops
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Post by sbwnik on Apr 14, 2014 22:05:54 GMT
Probably exactly that. I'll check with a mate who runs them all the time, see what he thinks
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Post by kru251 on Apr 15, 2014 5:41:56 GMT
I can't comment on riding a tuned Malossi, but having gone from a std cast iron barrel PX200EFL to a new ali barrel with light porting I can say there DEFINITELY is a change in sound. More ringing and rattling when cold and different on the overrun/ light throttle settings. All to do with expansion rates of piston/barrel material etc. Annoyed the heck out of me initially. A year on I don't think of it as anything other than 'normal'. Performance is better and I hope the ali means better cooling along with less weight (original weighed a tonne!)
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Post by henri on Apr 15, 2014 9:14:56 GMT
rab,as the noise goes when warm i'd agree with piston slap ,when the rings where done did the bore/piston clearance get measured ,havent got exact figures for malossi but from memory its a bit more than standard piaggio.to do with the ali piston's made from ,different grades of ali expand different amounts .as the scoot is still pulling decent mph cant ya live with it,might encourage you to fully warm engine up before going out in public .prolongs engine life amazingly long. H
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Post by rab on Apr 15, 2014 11:46:25 GMT
I only had the rings changed because of the rattle. bore was measured and new rings Orderd and put in It did not need oversize rings the bore and cylinder was fine so it's looking like I may have to live with it and get over myself lol . But I'll also wait to see what Nick s mate has to say it could be that it did actually need oversize rings and its been measured wrong. But with the replys I've had from you guys so far I'm more at ease with the rattle
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Post by sbwnik on Apr 15, 2014 19:12:56 GMT
Apparently they rattle like mad. Don't hone/rebore and get a larger piston as the WILL sieze.
Don't worry about it... "They do that"
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Post by rab on Apr 16, 2014 19:09:38 GMT
ok nick thanks for finding out ill live with it. dont supose you know anyone with a cheap ish end can for sale my sterling has just about had its day as i found out tonight. on the way home the scoot was over reving at standstill. miss fireing at set off so checked it out when i got home and the end can was hanging off so bodged it back on with some over size bolts the baffle packing inside is disgusting and the inner baffle pipe has snaped inside aswell scoot is running good again but probely not for long with the sate of the silencer
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Post by sbwnik on Apr 16, 2014 19:21:58 GMT
That's probably a part of the noise you've been listening to as well!
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