Still rattling malossi

Hello again,posted a topic about my rattling malossi kit a bout a month ago and acted on the info provided by a lot of you(cheers everyone)but,you guessed it the problem is still persisting.Something I forgot to mention last time was that I overheated the kit on the way back from cleethorpes last year and it had to have new piston rings(it didnt seize up fortunatley).The noise, a clanking on tickover is definatley from the cylinder barrel ,when I had the head off and moved the flywheel I could hear the noise seemingley coming from behind the piston.If however I put any pressure on the piston face with my finger the noise went.Now the latest theory is maybe that the little end bearing is shot(i`ve heard of oversize been used)or another that this noise is piston slap caused by my overheat and the lining of the barrel been affected.Any more ideas anyone?It is bad as my mate has the same set up and although his does rattle its not half as bad as mine ,vibration white finger on the way back from whitbyyyyyyyyyyyyyyyyyyyyyyyyyyy!!! Ideas gratefully apreciated JACKO

Well ive gone back standard for the time being and the scoot now runs sweet as a nut.Looking at the kit there seems to be a definate slack fit with the piston in the bore ,you can see daylight betwen the rings and the cylinder wall!It seems that the piston is round and the bore oval,standard job was a lovely tight fit(oo er)anyway back to the drawing board ,Im wondering if all this expense is worth it for an extra few miles an hour!!![:rotate:] [:rotate:] :rotate I`ll be mostly racing milkfloats and not corvettes me thinks!!! JACKO CNSC

Cheers for that its just that its had a new crank and bearings fitted not 300 miles since and its still doing it ,you see why im puzzled[:(] [:(] [:(] [:(] [:(] [:(]

mallosi is shit steel barrell polinis rule 90+ and no problems ask your local corvette driver t5 s eat corvettes for snacks




Sounds serious Jacko, wouldnt take it on any long trips again without sorting it...unless of course you like to travel by AA van ![:)] ...may be the small end bearing has started to crack up. If you catch it soon you may save the crank but if not you may find that there are grooves around the inside of the con-rod where the small end bearing runs (theres probably a technical name for that but buggered if I can think of it). If is still smooth put a new one in, you shouldnt have to go oversize. Cranks and Con-rods can be fixed but the cost of doing so usually means its cheaper to get a whole new crank. If its not that you may have to go deeper.... sounds to me like the big end could be starting to give out or (less likely) a main bearing. To check the big end take the barrel off look for any excessive horizontal movement in the conrod. It will move a little bit side to side but shouldnt really move at all front to back. Prob not piston slap unless you`ve done a heap of miles. Good luck.

Dont listen to Dylan, hes just tring to get his rank up higher than mine [:D]

I think I better rephrase the question,does any body have a malossi that doesnt rattle???[;)] [;)] [;)] [;)] [;)] [;)] [:D] Any way I had the head off and a mate of mine had a look and he seemed to think the piston was a slack fit in the barrel and thats where the noise is coming from,anymore ideas??? [:rolleyes:] [:rolleyes:] [:rolleyes:] [:rolleyes:]

[ Message edited by jacko on 14.04.2002 ]

should use steel barrel polini no crap alloy to oval

Jacko, a mate of mine used to race crossers he tells me that when a main bearing, clutch side/flywheel side bearing in are case, are on there way out this will cause a bad vibration through the handle bars.He also is pretty addament that because of the nature of the standard bearings are not quite up to the increased performance of the uprated kit.Hope this helps, also ive just got hold of a second hand engine and is being sent off to a well known Welsh engine tuner and is getting a full rebuild with malossi kit and reed conversion.ill keep you informed, i have the same problem as you with the engine im using at the moment and i swear the rattling is getting louder.[:drink:]

Sorry Jacko but just cause the crank is new doesnt mean it hasn`t crapped out. I friend of mine destroyed on one his standard Lambretta in less than 100 miles…there are some dodgy parts out there.

Just don`t write that possibility off yet.