MRC Forum- brought to you by www.morini-riders-club.com Member: g7AW3f

Anyone got a list of oil seal sizes for the 350 engine.I would like to make sure I can get them before I remove the existing ones during my enforced engine re- build.
New member by the way,Nov.07. New owner to, had my '83 Kanguro for a year now and really enjoyed it for my 60 mile daily commute on A and B roads until the gearbox failed at the end of October ( 41000 km).
The bearing cage collapsed on the output shaft bearing, the bearing behind the sprocket,fortunately I heard/felt a rumble and stopped quickly.Anyone heard of this happening before ?
When I got the bike it had a worn O ring chain on it so as I was only going to use it on the road, put on a smaller,44T rear sprocket and a new Renold 520 O ring chain.
I was'nt happy with the O ring chain as after about 2000 miles it still felt very stiff, yes it was adjusted properly. When I lubricated the chain there was much less drag.After another 1500 miles it was still very stiff so I eventually replaced it with a new ordinary, non O ring chain,what a difference, but, about a month later the bearing failed.
Had the damage been done,to much load on the bearing with the stiff O ring chain ? Also the previous chain had been an O ring type.
Anyway, the engine is stripped now and fortunately there is no internal damage, looking forward to getting it back on the road.
Oh, another thing, I don't really want to change anything much in the engine but I have a sport camshaft and wonder if this would be worthwhile fitting with everything else left as standard Kanguro, any advice would be welcome

Hello,

I might have a list of the seals on a s/sheet or invoice somewhere (for a sport ser 1) cannot vouch if they're all the same as later trail bikes though. Anyway, all the seals can be purchased readily from morini spares stockist or a brg factors.

G

almost forgot, the brg behind the spkt on my bike collapsed too (before I bought it). When I found play of about 1/4" on the shaft I knew I was in trouble! It possibly broke up because of poor maintenance/ too tight tension on the drive chain, anyway I had to split the engine - I didn't really want to, but found bits of bearing race and balls etc. throughout the internals.

I found that the seals all had the spec numbers embossed on the outer faces so just took the old ones to the local gearbox centre. You can get them from NLM of course and you will probably need one or two seals eg the oil pump one from them anyway. A tight chain would strain a bearing. I have only experience of BMW output bearings going, (they all do that sir) but though an acquired art to fix at least I don't have to split crankcases. I would be interested to know if this is a common failing too.

I believe that NLM automatically change the output bearing if they have to split the cases for any reason, certainly on the 500's, but probably also on the 350. They do lead a hard life, particularly with a poorly adjusted chain, but I've never heard of it as a weak point.

If the engine is an early type with a ball race on the timing side (as opposed to the later plain bearing) NLM will often convert to the 'race spec.' roller bearing if the cases are apart.

Thanks for the responses to my message re oil seals.
As stated, it was easy to pick up the sizes required.I replaced the ones easy to get at plus the output shaft one which had disintegrated when the bearing collapsed.
Having only stripped British bikes in the past,I have never had a bike with so many oil seals. Anyway, they must be common sizes as they were very reasonable from a bearing supplier.
The rebuild is well underway and if all goes to plan, (difficult sometimes when others have demands on your time ) should have the engine ready to go back in the frame by the weekend.Need to get a move on as the weather seams to be picking up.
Derek

I didn't know British bikes had any oil seal at all ???

Bruno