fastdruid wrote:Don't forget that with a new crank you will need new crank shell bearings as almost guaranteed the new crank will be different size to the original.
ISTR the haynes manual goes into the details for working out the different sizes from the markings but ideally you should get and use some plastigage.

Druid

Right going to sound a complete dunce now but i have never heard of plastigage. What is it, how do you use it and where can you but it from thanks...

Its like little strips of plastic looking stuff, you lay a strip on the crankshaft journal, close the crankcase&tighten, open up again and compare the thickness of the strip which has now been squashed.. This gives the oil space between bearing and journal. Not sure where to get it there, its a slightly specialised thing but spares places/motorcycle shops might have.

And the crankshaft journal would be the ends of the shaft (Am i correct.) Haven't got that far with the stripdown yet so just trying to build a mental picture..

The journals are the machined parts of the crankshaft that sit in the bearing shell sets, theres four main journals on the crankshaft and they have oil holes out their centres. Your putting plastigauge on them to check the oil clearance for each journal.. It really is a good idea to do all the checks the haynes suggests, going to the effort to buy another crank and all, may as well make sure it all works properly.. Take your time on the rebuild to get everything right, but it also gets annoying after a month cos you want to ride the fakkin thing as well!

*EDIT*
Just realised, your current bearing shells wont be the right size, check the haynes selection table and order based on that, the shells are colour coded, then use the plastigauge on the new shells.. If you select the right shells tho, the clearances will def be correct unless the journals are worn, in which case they'l appear slightly scratched

http://www.frost.co.uk/item_Detail.asp? ... lastigauge" onclick="window.open(this.href);return false;

Druid

MexicanGringo wrote:Just realised, your current bearing shells wont be the right size, check the haynes selection table and order based on that, the shells are colour coded,

Yes, this was my point, you cannot just put in the new crank and hope it'll work.

then use the plastigauge on the new shells.. If you select the right shells tho, the clearances will def be correct unless the journals are worn, in which case they'l appear slightly scratched

Hmmm, *ideally* yes but then you may need to buy two sets of shells depending on what it reads and how worn they are, depends really how worn the old ones are (and what size they were) as to if you can use them to work out the exact clearance before ordering shells, of course you may also find that a few of the new ones can be swapped round to make perfect clearances without ordering two sets.

Druid

The variable here is the size of the journals, as the size of the bearings will be known if all new bearings are purchased. The crank journal code indicates whether the journal is 29.994-30.002 or 30.002 - 30.010, if you could measure them with a micrometer youd know whether to replace with the theoretical correct bearings.

The case should be marked, this along with the markings on (or measurements from) the crank should tell you what size to purchase but doesn't take into account any wear.

Druid

Druids making the case for non lazyness, id say also def check with plastigauge then after selecting the theoretical correct bearings.. Its recommended to change all crank bearings at the same time

Druid's right! (He's always right)

Do it properly and dont' be tempted to skip any step.

Also, double check EVERYTHING, plastigague usually comes with plenty spare.

The extra time spent making sure everything is back to how Mr Honda inteneded will pay off after you start the motor up and it doesn't produce a noise akin to dry clutch rattle.