Cylinder head re-torqued – 8 Jun 2016.

The Racing Rhino has now been back in use for 3 months and completed 537 miles so it was time to re-torque the head bolts.

The first thing to do was to take out the spark plugs and select top gear so that I could turn the engine over using the back wheel. I decided to do the left hand side first and removed the rocker cover.

DSCF2592-1

The rocker arms are different colours but that is how they’ve always been. It must be something to do with manufacturing as the exhaust rocker on the other side is brown as well – the same part.

I then turned the engine in the correct direction using the back wheel until the piston was at TDC on the compression stroke so that both rockers are loose. I then slackened off the adjusters. The rockers were removed by undoing the locking screws and sliding out the shafts. Parts were kept together so they couldn’t get interchanged. There’s a washer, spring, rocker arm, shaft and locking screw with spring washer for each valve.

Next I removed the 26mm blanking plug and its crush washer from the top of the cylinder head.

DSCF2595-1

This covers the top cylinder head mounting nut which needs a 10mm Allen key. This is what I use.

DSCF2593-1

All six of the nuts on the cylinder mounting studs are now accessible and should be slackened a half a turn or so in a diagonal sequence. I do the top sleeve nut first with the Allen key then change to a 17mm socket and loosen the nut by the spark plug. Then out of the remaining four I do lower left, upper right, lower right and upper left.

It’s now time to get out the torque wrench and tighten them all up again. The factory manual quotes a torque of 29 to 32 ft/lb and it’s easy to set my click-stop wrench to 32 so this is what I use. I do the tightening in the reverse order to the loosening, finishing with the top sleeve nut.

The blanking plug is replaced with the crush washer. It needs to seal or oil will leak onto the top of the cylinder barrel and work its way around the cylinder till it appears below the plug.

Next, the rocker gear is replaced. I hold a group – washer, spring and rocker arm – together and fit it in the support. Then I use a screwdriver to line them up as best I can before inserting the rocker shaft. The shaft has a screwdriver slot in the lower end so you can turn it till the hole is in position and the locking screw can be fitted. It is important that only the correct original length screw is used to hold the shafts in place. If the screw is too long it will block the oil feed to the rocker. Not good. Also, the torque figure for that screw is fairly low at 4.2 to 5.7 ft/lb so I just tighten them with a short spanner.

With the rocker gear replaced, and the piston still at TDC, I adjusted the valve clearances. The factory manual gives a figure of 0.22mm. I set them all at 0.2mm which is close enough given that there is a very small amount of wear in the pads on the ends of the rocker arms.

The rocker box went on next after adding a bit more grease to the gasket so that it will come apart easily next time. I generally tighten all the small Allen bolts in a diagonal pattern using a short key so as not to over tighten them and strip the threads in the head.

The same job was then done on the other side.

First engine oil change.

I decided that I would change the engine oil now that the first stage of “running in” is complete.

DSCF2596-1

I rubbed the oil between my fingers and it seemed pretty clean which was a good sign. On the spur of the moment I decided I would remove the sump and check for any nasty bits of metal. The V7Sport doesn’t have an oil filter cartridge, just a filter screen.

I removed the screws but the sump wouldn’t come off. It was well and truly stuck. I replaced the drain plug and gave it a bash with a mallet but it didn’t move. I know better than to thump the sump itself as there’s a good chance the fins will break off. Wedging screwdrivers in the joint face is a no-no as well. I have a very thin-bladed scraper which I carefully knocked into the gasket itself to split the gasket material. Having got it off, it was clear that I hadn’t greased the gasket before fitting it during the engine rebuild and, after fighting to get the sump off, it was good to see there were no nasties in there. So, I just wiped it out.

I then had to spend a long time carefully scraping off the remains of the gasket without damaging the gasket faces. That was easy enough on the sump but, I had the bike on the ground and had to scrape the bottom of the engine block while laying on the floor.

Eventually all was cleaned to my satisfaction and I refitted the sump with a new gasket. I didn’t have the correct sort so cut the redundant parts off a gasket intended for the later models with a cartridge oil filter.

DSCF2597-1

This time I made sure the gasket got a coating of grease so it shouldn’t be stuck next time. On these bikes you don’t need to keep taking off the sump to change an oil filter but, I still like to take it off and give it and the filter screen a clean from time to time.

Then it was sump plug back in with a new crush washer and 3.5 litres of engine oil added.

That’s it for today. However, I’ll be back soon as I’ve bought a trailer to tow behind the bikes! Hmm.

DSCF2567-1

Advertisements

2 thoughts on “Cylinder head re-torqued – 8 Jun 2016.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s