Scooterotica

i am restoring an old T5 classic and have taken out the engine
striped it and cleaned it up and using the scooter techniques DVD
replaced the bearings and cruciform
however when i put together the two halfs of the engine
and tighten up the bolts the crankshaft locks up and wont turn

any suggestions as to what im doing wrong?

as im sure the crankshaft itself is true

it could be one of the two masses that has moved if the crankshaft fell to the ground for example. Make sure the 2 masses of the crank are parallel. Use a comparator (crankshaft gauge ?)

Sometime it can just be 1mm move and you just need a copper hammer without rebound

okay thanks for that will have a look as the
engine has been lying in a box in bits for a good
few years and has been moved about a lot

can you pull in the crank too far on the bearing
on the main engine side? as when the halfs are bolted together
the crank web to engine casing gap seems lopsided

No you can't, but a possible issue is that your oil seal on the main bearing is not pressed enough and then it can block the crank.

do you mean the big strange looking metal oil seal on
the main engine block side?
also is it ok to tap out the crank (gently) with a hammer
or will i have to get a dedicated extractor?

the oil seal must be absolutely its case absolutely flat

yes thats the one
i will get onto it tomorrow and see what i can find
thanks

stripped the engine down and i think your right with
the seal lip not being totally flush so its now tapped in flush
had a look at the crank and it seems to be true enough but its
not easy to be certain seen as the webs are different diameters
to each other
also made sure when i was drawing it into the main bearings
that it was square coming into the housing and was not rubbing
anywhere and have left it backed off a millimetre from
being fully seated to give me some room to play with

ill have to leave it for now till i get a new engine gasket as the
existing one ripped when splitting the engine......

when you install your casing gasket use some grease so when you have to split the cases, the gasket is still ok

i did that as per the ST dvd but it still split....

all part of the learning curve i suppose

will update when a new gasket arrives