Replacement Cylinder Head Casting

[bureklton]

Hey guys,

First time poster and new to road bikes with a CB400 super four that I bought for a project

http://photos2.donedeal.ie/motorbikes/c ... 9854.jpeg#
http://photos2.donedeal.ie/motorbikes/c ... 39848.jpeg
http://photos2.donedeal.ie/motorbikes/c ... 39849.jpeg

I got it home and running last weekend only to discover than two bolts in the cylinder head exhaust ports have been sheared inside the block. The engine is a NC23 E and I have looked online for one (Part # 12010-KT8-010)but they either cost over a grand or are not available.

I am going to try and drill the bolts out but the previous owner had a go at one and well lets just say he shouldn't have been given scissors around the bike. As a plan B however does anyone have an ideas where I'd get a refurbished part or what other bikes would have similar fitting casings?

Cheers for the help guys

[willandrip]

Pics no good; viewer needs a log in code.
Use photobucket or imageshack !

Take the head to a proper motor engineer; they will have fixed much, much worse.

It is not a complicated job for the home mechanic; provided you have skills, access and the correct tools.

[bureklton]

Ah sorry about that, I'll get new ones up soon.

Do you think they would be able to fill be holes with weld (TIG aluminium) without wrapping the cylinder head? The previous owner tried to drill out the bolt but was way off center and drilled out a good portion of the parent material out. I would use a heli coil but I'd be afraid there isn't enough of the parent material left to stop the casting from breaking.

Any suggestions where UI could get this done?

Cheers

Eoin

[willandrip]

Why certainly they could; it is bread and butter work.(you mean warping not wrapping ?)
A good firm will use an insert rather than a helicoil.

Look for engine reconditioners in your phone book and go visit a local one.
You will gain far more information from the man in the old brown shop coat that does the work than the receptionist on
the other end of the phone doing her nails/facebook.

[bureklton]

Found a casting off a 92 cb-1. Will it fit my cb400 super four? Its only 50 quid so would be cheaper than a repair.

[billgrundies]

just bought some barrels for my 1993 nc23e. was offered a couple of heads and barrels and told they were off nc23 engines I found they looked the same as mine but they were not camchain run but used a cog instead. I have been buying engine parts only with MY9 cast or marked on them with no problems.