Aye Gareth, one of those days, EH!
I suspect that you have drilled into the water/coolant jacket at the back of the studs.
I would suggest a fix using some "QuikSteel Steel Reinforced Epoxy Putty – Metal Instant Repair Filler" available from Frost's and other suppliers.
Here are the claims:
"Sets steel hard within 15 to 30 minutes, even under water, achieving a full chemical cure within 60 minutes. It’s impervious to petrol, diesel, and oil – even battery acid.
Permanently bonds to aluminium, brass, copper, steel, PVC, fibre glass, plastics, glass, wood and more.
Repairs leaking fuel tanks, kerbed alloys, and stone damaged radiators, cracked sumps, stripped threads, and exhausts. Around the home it can fix anything from leaking guttering to a leaking central heating pipe.
Is 260°C (500°F) temperature resistant and it is drinking water safe.
Bond holds to -32°C (90°F)"
I will send direct via email, a workshop manual for an SZR660 that uses the same motor.
Further advice
BEFORE stuffing 'monkey metal' up the stud hole should be obtained from Slipstream Tuning, in Sevenoaks, Kent. Martin Sweet is the boss and knows these motors inside out. His shop foreman is also very knowledgeable. Contact number: 01732 743248 or email: martin@teamslipstream.co.uk the latter maybe slow due to semi-retiral!
Website:
Slipstream_TuningMy advise would be to read the manual before doing anymore 'stripping'.
Take your time and keep it all clean and tidy, clean bits as you go and label and photograph the layout/location of everything!
Use a lot of Plus+Gas 'A' on all of the fasteners before attempting removal. Keep everything in cardboard sheets, there are 15 set screws holding the rocker cover on and there are copper washers on some of them, so as not to jumble them.
It is essential that you don't drop the timing chain inside the cylinder barrel tunnel or let it go slack and come off the bottom sprocket. SteveH did this with an SRX (which is of the same design) and snapped the locating casting for the chain tensioner blade! You are warned!
For parts, Fowler's of Bristol are the best, just be prepared for your wallet to be lighter! I suspect that the motor will be a '3YF*' or a '4BW*' number as these were made at the same time as Yamaha's XT660Z. Number on R/H crankcase above gear change in oblong casting.
This is the link to Fowler's parts list for these engine models and give full exploded diagrams of components, parts numbers and prices etc:
1993_XT660Z_Tenere_parts_list Their spares staff on the phone have always proved capable when I have called to clarify specs. or part numbers.
I hope this all helps. And don't think you are alone! The Honda Bros 400 was the only roadworthy bike of the fleet and after a wee 30 mile round trip today, returned home with a 'blown' forkseal!
More spannering.
My regards, Bill
