I recently took ownership of an NC29 which has just undergone the works listed below following a two year sitting period from the previous owner:

New rear suspension
New high performance fork seals and oil
New rear tyre
New front and rear brake pads
New rear caliper and brake lines
New brake fluids
Carbs balanced and pressure cleaned
Engine oil changed
New battery
New handgrips

However on it's first ride (today) after 3 miles, the temp gauge hardly moved and the rad was cold. Upon inspection there was now oil in the rad and water in the oil. Oh well, seems after two years of sitting I believe the head gasket to have deteriorated.

Has anyone any thoughts of cost (I estimate £300) and advice whilst it's being replaced, as I know one of the valve stems is also letting oil go potentially. I am not after 'upgrades' merely replacing items or a clean up whilst it's being worked upon perhaps. Someone highlighted getting the head refurbished and piston rings replaced for example.

The bike is a 1990 with 17,000 miles.

Thank you.

The head gaskets are metal they don't deteriorate.

When it was stored did it have antifreeze in it this could be a lot more serious than just a gasket which I honestly doubt it is.
If this were my bike I would drop the engine out and replace the head gasket myself, all you need is a socket set, Allan keys, torque wrench and a Haynes manual, take your time and read the Haynes and you could have then engine out gasket replaced and the engine back in in a weekend.

This will be your cheapest option, if the bike has been left to freeze in the -15 winter we had the leak could be anywhere from the head through the block as far as the oil cooler.

If you get a shop to do this you are looking at £60 for a gasket + 8 hours labour at £40-£60 an hour which at the end may not even fix the issue.

^^ What he said.

Get the head off and do it yourself. It is not so difficult at the end of the day

Well it sure enough is the head gasket. Where is best to buy a good quality head gasket please? AT least it's a chance to do other work such a stem seals.

cosy wrote:Well it sure enough is the head gasket. Where is best to buy a good quality head gasket please? AT least it's a chance to do other work such a stem seals.

Compare prices of:

David Silver Spares
Lings Honda
WE Moto

cosy wrote:Well it sure enough is the head gasket. Where is best to buy a good quality head gasket please? AT least it's a chance to do other work such a stem seals.

Just out of interest how do you know, have you had the head off, has the gasket split/torn/melted?

I only ask as I have owned multiple 29s (this is number 5 or 6) and been around them for around 10 years and other than on a race bike I have never known a head gasket go on one of these bikes.

Just interested like...

Big job to do if you arent totally sure. Oil in coolant doesnt always mean a head gasket

I remember an old YZ400 MX bike of mine a few years back, thought the head gasket had gone when we found coolant in the oil and visa versa.

However turned out to simply be the oil seal in the water pump on the impeller shaft allowing oil to pass through it..

Is there a loss in performance/low compression on any/all cylinders?

Well a long story short, the head gasket was replaced, rode one mile and it went again, so after a close examination, there was a three inch crack in the head, seems the previous owner had left pure water over two and a half years so no points as to what happened over the course of the bad winter periods.

Still it has been welded and after 50 plus miles, I can report a clean bill of health.

So note to all as already highlighted, if you suspect a common failure, always investigate further.

Appreciate the input thank you.

So it wasn't the head gasket then

Glad you got it sorted in the end.

Thank you. Glad it's fixed, just the fuelling issues to tackle and I will be away.