crank bearings shot---need help on replacements.

[spitfire123]

right,

just discoverd that my main bearings are gone..the have movment in the L/H side.

so....

the ones allready on it have rubber seals on the outside edges of the bearing.....

there is this set on ebay from a fellow on here i belive:
https://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=120421808148&ssPageName=ADME:X:RTQ:GB:1123

he advises me that they are 'caged bearings' and do not need the rubber/plastic seals and assures me these are better quality for that.

but this dearer set of £40 apears to come with rubber seals for the bearings as i would of though they should?no?

here is the link:
https://cgi.ebay.co.uk/Cagiva-Mito-125-Main-Bearing-Seal-Kit-crank-bearing_W0QQitemZ370186418229QQcmdZViewItemQQptZUK_Motorcycle_Parts?hash=item370186418229&_trksid=p3286.c0.m14&_trkparms=72%3A1683%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318%7C301%3A0%7C293%3A1%7C294%3A50

so do they or do they not need the oil seals?

it says in the description they are bioth c4 bearings? im presuming there the same?

any help is MUCH arpiciated.

CHEERS
____________________
You won't be able to eat my dust......As it'll settle before you get there.

[spitfire123]

ok the boots ove found from the diogram are external and go over to protetct gearbox oil from entering the engine.


aso:

is it possible to remove the bearing without splitting the engine and just slotting the new bearings in,lol?


cheers
____________________
You won't be able to eat my dust......As it'll settle before you get there.

[Kickstart]

Hi

Never seen a sealed bearing used on a 2 stroke crack, and would expect the drag from the bearings running in grease to be rather greater.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[stinkwheel]

But, if you buy sealed ones, it is a matter of a few seconds to ping the seals out using a small, pointy screwdriver.

My Number 1 piece of advice is to take the old ones with you to a bearing factors and ask them to supply you with new ones. Look in the yellow pages under bearing factors. It will usually be called Town name Bearings and Transmissions. Don't go in there asking for one for a Cagiva, you'll only piss them off, take the old one.

If you are replacing the mains, do the oil seals at the same time. You'll be proper pissed off if you get it all together and the seals leak (believe me!).
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[spitfire123]

[spitfire123]

is it acturly possible to remove the bearings and slot new ones in without splitting the engine?

cheers
____________________
You won't be able to eat my dust......As it'll settle before you get there.

[Kickstart]

[spitfire123]

[Kickstart]

Hi

Could well be. How much play is there on the end of the crank?

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[spitfire123]

[Kickstart]

Hi

Possible, but normally they whine when they wear out. I would be be inclined to check elsewhere as well (eg, big end bearing condition, even a piston that is heavier / lighter than standard).

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[spitfire123]

[Kickstart]

[spitfire123]

[Kickstart]

Hi

Personally if you are going to the effort and expense of a full strip down then just put a new con rod kit in it.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[spitfire123]

[Kickstart]

Hi

Could be that the person who did the last crank rebuild didn't know what they were doing and didn't true it up.

I know that with the RS125, cack handed assembly (ie, tightening the bolts that hold the crankcase halves together to pull the crank halves onto the crank) will wreck the main bearings quite repidly.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[spitfire123]

[Kickstart]

Hi

Idea is that you pull the crank into the bearing, rather than push the bearing / crankcase half onto crank. Result should be a tiny amount of side to side movement in the crank.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[spitfire123]