B Measure the height of the camshaft lobes with a micrometer

14If the Plastigauge method is to be used, clean the camshafts, the bearing surfaces in the cylinder head and camsh.afl holders with a clean lint-free cloth, then lay the camshafts in place in the cylinder head.

15Cut strips of Plastigauge and lay one piece on each bearing journal, parallel with the camshaft centreline (see illustration).Make sure the camshaft holder dowels are in position then fit the holders, making sure they are in their correct location (see Step 5). Tighten the holder bolts evenly and a little at a time in a criss-cross pattern to the torque setting specified at the beginning of the Chapter. While doing this, don't let the camshafts rotate.

16 Now unscrew the bolts evenly and a little at atime in a criss-cross pattern, and carefully lift off the camshaft holders.

17To determine the oil clearance, compare the crushed Plastigauge (at its widest point) on each journal to the scale printed on the Plastigauge container (see illustration).Compare the results to this Chapter's Specifications. Carefully clean away all traces of the Plastigauge using a fingernail or other object which will not score the bearing surfaces.

18If any clearance Is greater than specified, it is an indication of wear on the camshaft, the holder, or both. First check to see if the camshaft journals are worn below the service limit. If they are, a new camshaft must be

Measure the cam bearing journals with a micrometer

Lay a strip of Plastigauge across

Each bearing journal, parallel with the

Camshaft centreline

Compare the width of the crushed

Plastigauge to the scale printed on the

Plastigauge container

2»14 Engine, clutch and transmission

A Locate the camchain on the

Camshaft sprockets, keeping the front run

Of the chain tight

fitted. However, since it is likely that the holders are also worn, use the journal diameter specification for a new camshaft to calculate whether fitting a new camshaft will restore the oil clearance to within specification.

19 If the camshaft journals are good, or if fitting a new camshaft will not restore the oil clearance to within specification, the holders and cylinder head must be renewed.

IfTOJTSI Before renewing camshafts
^lr or holders because of

damage, check with local machine shops specialising in motorcycle engine work. In the case of the camshafts, it may be possible for cam lobes to be welded, reground and hardened, at a cost far lower than that of a new camshaft. If the bearing surfaces in the holders are damaged, it may be possible for them to be bored out to accept bearing inserts. Due to the cost of new components it is recommended that all options be explored.

Date: 2016-01-14; view: 796