Triumphrat

hillclimber · 12-30-2005

I'm just wondering how much wear is tolerable.

After removing the valve springs, 3 of my guides seem really good, but the left exaust guide has more play than the others. I get about .008-.010" play on that one valve.
I measured the valvestems with Starrett digital calipers. They only have about .003 wear (if that), and they are for the most part identical.
The seats also look good, although that one valve had more crud around the guide (inside the rocker box).
The guides look original and haven't been knurled or anything.
I'm looking for opinions here.
Am I being too picky, or should I just say screw it and go with new valves and guides??
Keep in mind that this bike hasn't been run since '87 and it looks like the head will have to go to the machine shop anyway to have 2 broken sparkplugs removed (nothing left in the head but the threads).

I'm sure it sounds like I'm trying to get out of it cheap, but I'm sure I'm gonna be finding MUCH more stuff that needs to be replaced as I go along.
I don't want to butcher it though, as the bike is all original.
It's rough in spots, but it's all there.

[ This message was edited by: hillclimber on 2005-12-30 02:48 ]

tommyturbo2 · 12-30-2005

Hillclimber: Definitely replace your guides and valves, and have a valve job done, since your going to have the head at a machine shop anyway. Then you'll know your starting with a fresh top-end. I'd go ahead and do an .020 overbore with new pistons and rings. Parts for the old stuff are readily available and cheap compared to the new bikes. Cheers, tommyturbo2

jimballard · 12-30-2005

When I owned my '72 Daytona 500 I had the engine balanced and at that time, the valve guides were done as well. The factory ones were bronze and they wore quite quickly. They were replaced with steel ones (or cast iron?...memory is a fleeting thing) with no further problems.

Just my $.02 worth: Jim

panda · 12-30-2005

It is such an easy job to do , I would just see if the valve has been seating well on the seat.. valve to seat seal good. if so leave it alone, after you have run it a while, if it causes you any problem it can easily be rectified. to some extent this also applies to the bores... basically do as little as seems reasonable when working on the top end, as it is no problem to go back in... Of course if you were a commercial rebuilder, and had to give warranties it might pay to change everything.... but for teh home owner walk slowly.....
I am sure you will find other opportunities to spend money on it

texspeed · 01-01-2006

Check out M.A.P in Florida. They have some excellent modern design valve guides along with the valves to go along with them.... I'd avoid oem guides.

HOPOIL · 01-03-2006

Hi Hillclimber;
I whole-heartedly second Texspeed"s recommendation towards the M.A.P. valve guides.
I had my 750 overhauled last winter and my Trusty/Crusty mechanic uses MAP stuff. These newer guides have an oil seal that will help keep the oil in the rocker area and not in the combustion chamber, so the theory goes.
Suggest that the machine shop person do a thorough assessment of the cylinder bore/piston wear - you might want to choose a .40 over bore. That's what we did - seems my bores were worn out near the .20 range but Trusty/Crusty said at no additional cost (.40 pistons vs .20 pistons etc) I would ended up with a much better fit by taking it out to the second overbore.
His wisdon seems to bear this out as the bike runs much better than before the work (plus a little more displacement).

good luck :hammer: