Cylinder Head Problems

[bogey]

Hi All,
Still trying to finish rebuilding my RD500 but it seams one step forward two steps back. Have the chases etc pretty much done and engine back in and all connected up. Went to fill it with coolant but had a leak on the front cylinder head, specifically from studs 1 & 4 and a trace from 5 & 8.

When i stripped it it had holed a piston in cylinder no 2 and I had a local bike shop who was recommended to me by another 500 owner whose engine they had worked on, do the repair work. This work was done a few years ago now (Thats how long its taken me to get the bike back together) so not really keen to bring it back. I checked over everything before putting engine back into the chases and everything seemed pretty good. I am thinking maybe a spurious gasket was used and that that may be the problem.

Anyway the plan is to strip the head off and have a look and put back on with a genuine yamaha head gasket.

My question is this. I understood that it s the 4 studs that go across the centre of the head i.e. studs no's 1,4,9, & 10 that have copper washers fitted. The problem is when I look in the manual or on the parts fiche it shows washers on studs 5 & 8 on the back head and on studs 2 & 3 on the front head, although in the manual the studs across the middle have an asterisks which when you refer to it states that there should be a copper washer on these studs.

In the Parts fiche or some of the online parts lists there is a part no shown for the washers shown in the diagram but not for the copper items required.

Is this a mistake in the diagrams or do all studs have washers with the ones across the centre the copper type ??

Hope this is not too confusing and would be very grateful for any advice/comments/help.

Regards
B

[Rick Lance]

As you mentioned, studs 1,4,9 and 10 that run across the center row on both heads are wet and need to be sealed with copper washers and acorn nuts (sealed top). Non-factory original head gaskets sourced from Vesrah and others are known leakers. Stock Yamaha head gaskets are mandatory. Remember that the gasket marked #1 goes on top with #2 on the lower cylinders.

A water leak indicates a lack of expertise with your motor that may prompt you to dig further to determine exactly what was done and how.

[silverstrom]

All 4 center studs on each head need the copper washers and dome nuts to seal properly at they all go into water jackets. All four of the parts lists (RZ500 47X, RZ500 1GE, RZ500 S, and RZV500) show nut, crown, quantity 8 and washer, plate, quantity 8. You need to pay attention to the quantity, not so much the locations it shows. The parts lists are lacking in that respect.

[bogey]

Thanks for the replies guys, I have a genuine head gasket on order and a set of copper washers. Took the head off and at first glance all looks pretty good. Will have a closer look at the bores later.

When I took the head off there were plain washers on studs 6, 2, 3 & 7 i.e. those across the top side of the head but none on studs 5 & 8 which hold on the stone guard, is this right??

Regards
B