Replace the Shells - Rebuild

[Fields]

Hi all, new here, was on this a good few years ago but looking at giving a mate a hand replacing the shells on the crank of a NC30. Is this a big job or is it ok with the service manual and proper tooling? Worked as toolmaker for years so I'm ok working with fine tolerance work. Just wondering about the actual procedure thats all.

Cheers

Ian.

[Neosophist]

its big in terms of you have to take pretty much all the motor apart.

Its not difficult if you have the correct tools and know what your doing.

If your a fairly competent mechanic then im sure you can do it with the service manual on the site and maybe the haynes book if you need a bit more back story.

[Fields]

Cheers for the reply, yeah as far as I know he has the motor stripped and all the parts on the way, apart from checking measurements/tolerances/torque values, is there any special tooling needed? I got the service manual off the net, is the haynes manual any more descriptive?

[hunter]

Before you order the shell bearings read the haynes manual,
Page 2.47.The bearings are colour coded.

[NGneer]

Before you order the shell bearings read the haynes manual,
Page 2.47.The bearings are colour coded.

A FULL engine overhaul is also on my (ever expanding) list of things to do at some point and while I am happy enough with the actual engine strip and rebuild, I have always wondered about the crank/shell bearings. I know they are colour coded acording to their size/clearance, but how do you check what size you need? Is it down to using plasti-gauges and converting the figure they provide into the nearest Honda size and colour code?

[dobbslc]

Plastigauge is what I used on all the bearing journals on my FZR. It's time consuming and a bit fiddly but does give you the correct clearances for your new bearings. If the crank and big end journals are within spec you could probably just swap old for new, matching the colours on the old shells.
I found the book 'four stroke performance tuning' by A Graham Bell to be very useful on all things to do with engine tuning. Ebay 261531972257
He does a two stroke one as well if you really want to have your brain fried!

[hunter]

Plenty of info out there.
https://www.youtube.com/watch?v=rXp1vVtsp7s

http://www.ebay.co.uk/itm/Plastigauge-p ... 4d0e2b8534

[lukemillar]

It is better to measure and select the shells accordingly rather than go purely on the colour code based on the crank and journals codes. I found that 2 matched up with Honda but the other 2 would have been close to the limit and switching to thicker shells was the way to go to bring them all in line. I think the Honda service manual gives the shell thickness whereas Haynes doesn't.

Cheers
Luke

[Malc]

Before you order the shell bearings read the haynes manual,
Page 2.47.The bearings are colour coded.

A FULL engine overhaul is also on my (ever expanding) list of things to do at some point and while I am happy enough with the actual engine strip and rebuild, I have always wondered about the crank/shell bearings. I know they are colour coded acording to their size/clearance, but how do you check what size you need? Is it down to using plasti-gauges and converting the figure they provide into the nearest Honda size and colour code?

I done a couple in the past - on both occasions I took the easy way and bought the new shells through Rick Oliver. He was really good in that I sent him all the codes off the stampings and etches, etc. and he sourced then sent them all bagged up ready to fit where they should. It was handy in that he backed up what I thought I needed to order anyhow - its not that difficult to size them up yourself.