hi all basically i bought i firefox 50 as a cheap run around. i removed engine and installed a new crank ..using the hot and cold method,upon installation the crank was a bit stiff to turn. i gave it a few nocks with a mallet and seemed all good after that.i then put engine all back togeather ot it all running nice but had a bit bother bleeding the cooling system .anyway i thught i had it sorted so went for a drive and it died on me,got it going and then died again.im guessing head gaskets gone. but what id like to no is when installing a new crank what do you lube the new main bearings with? and also big end and small end? i also found out you need to bleed oil pump? any help would be apreciated .
2 stroke oil? You generally cover everything in it when it's built and it smokes like a bastard for the first few tanks of petrol.
It's how 2 stroke engines work. The mixture is pulled into the crankcase the up into the cylinder. The mixture of oil and petrol goes through the lot.
ah right thanks alot ...ive coverd them in grease so looks like a stripdown again..could you give me info on centering a crank? and bleeding oil pump please?
I don't know how to bleed an oil pump on a minarelli. Best thing would be to buy a haynes manual for your bike which if you are doing any work on it you should have anyway. It seems like you might already have the right idea for centering a crank. It should move freely with little or no effort.
also i had to get a second hand side casing for it as the origional was broke. both are exactly the same but the original as a hole going down to the the mains from the reed blocks...wheras the replacement has the hole in the cylinder bit of the case.will these make a difference?
The are just feeds to allow oil/fuel into the bearings a bit better. Never understood why on minarellis they seem to randomly move them about. It won't really matter either way.
