Hi - I have a motorcycle cylinder head with leaking valves (SuZuki DR650). Can anyone recommend a place in Auckland that could repair this at a reasonable $$? Thanks.
kazbanz,
Jan 5, 8:19am
Coleman’s Suzuki, Auckland motorcycle services both come to mind.
mechnificent,
Jan 5, 8:28am
If you want engineering done, machining, then go to a engine reconditioner.
kazbanz,
Jan 5, 10:56am
To pop the head and change/lap valves on a DR? Even if it needs a 3 angle cut most reco shops don't have cutters small enough.
mechnificent,
Jan 5, 11:09am
Don't they ? They should have. We can make the stones as big or small as we want.
mechnificent,
Jan 5, 11:10am
He says he has a head. I was imagining it's already off. Might be wrong.
If it's still on the motor then a MC shop.
kazbanz,
Jan 5, 12:35pm
I must just be "unlucky" because I haven't yet had any joy getting motorcycle heads machined in a automotive engine reco shop. Cams wise Sure thing Franklin cams are the go to guys. But not head work. With the DR I would guess unless the OP is lucky that its going to need new valve seats. -1mm oversize is max on standard seats. also if it is valve leakage my guess is the cam followers will also need attention.
mechnificent,
Jan 5, 12:40pm
Oh yeah. That's strange because as I say, we can cut stones down to as small as we want. We can cut seats only about fifteen mills diameter.
Perhaps it's just the job is too small. not enough valves.
Small valves are generally ok to just lap in anyway OP. You could invest in a pot of grinding compound and a sucker. about ten bucks probably, and check how they lap in. It's only a DR. They're bulletproof.
mechnificent,
Jan 5, 12:45pm
And OP. being a single, there's not much scope for them to burn valves too bad, unlike a multi cylinder. You'll probably find they lap in fine and with only a few minutes work each.
tygertung,
Jan 5, 5:01pm
I have actually ground valves in a drill press with a die grinder. Just grind a nice round taper on the valves. You will want a reasonably fine stone though otherwise it takes forever to lap them in afterwards. The flow is better apparently with the rounded seats.
I used to do that when I was racing motorcycles.
mechnificent,
Jan 5, 5:07pm
Nah you don't really want round seats. A little bit's ok, but it's not the best.
Wide seats don't have enough pressure on them, and if they are badly round there is one part that's going to be sitting down with a sliding action and some that doesn't. You get carbon buildup that slowly creeps wider and wider.
tygertung,
Jan 5, 6:44pm
The valves were round, the seats, well I just left them as I couldn't cut them.
mechnificent,
Jan 5, 6:45pm
The valves and the seats should be flat. and not too wide or narrow.
take it to a good engine reconditioners, we used to do them all the time when i did my time.
mechnificent,
Sep 30, 11:42am
Yeah Bill, I used to do them at work with the stone cutters. But everything's "specialist" now.
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