top end rebuild

[Guest]

Getting ready to start on my 850 top end rebuild. Going to use cylinder head and pistons from parts bike that had only 20,00o miles on it, and are in better condition than ones off my bike. Everything is in specs. Should I hone (deglaze) the cylinders or since I'm using same pistons and rings is this needed? Also this may be dumb question, but I've never lapped valves, should I lap them before putting in the new oil seals (old one removed) or put on new ones first? terrylee

[Big T]

The consensus is to give the bores a quick once over with the hone

And, check the valve faces for contact area before you lap them

They just need a 2-3 mm contact ring that is smooth

[terrylee]

Thanks, any idea on what size flex type honing tool to use? The cylinders measure about 69mm or 2.78 in. Found some on ebay that are for 2 7/8 cylinder, figured those would work? terrylee

[rustybronco]

http://ww1.prweb.com/prfiles/2013/05/29/10842773/Flex-Hone_Resource_Guide.pdf

http://thegsresources.com/_forum/showthread.php?p=1864074#post1864074

And if I recall correctly, Nessism had a thread on grit sizes. You might want to look for it.

[terrylee]

Thanks great info.! terrylee

[cowboyup3371]

Steve and I posted up a how to about lapping valves on Basscliff's site; might help out http://members.dslextreme.com/users/...LAP_VALVES.pdf


And do it before putting in the new seals

[terrylee]

Thanks. I just lightly lapped my valves today, since they all looked pretty good. I did so before installing seals. Got the seals installed, but was very nerve racking, making sure not to start them crooked and only tapping them very lightly till they seated down all the way. Had no desire to spend another $30. for new seals. It's good I'm following the Suzuki manual so I remember to put springs seats back on before installing seals. Plan to clean valves up a little with brass wire brush on my drill tomorrow. Then get all valves installed with my new "valve spring compressor tool" (8 in. c-clamp and O2 sensor socket). Thanks to whoever posted that on here! terrylee

[bwringer]

Thanks, any idea on what size flex type honing tool to use? The cylinders measure about 69mm or 2.78 in. Found some on ebay that are for 2 7/8 cylinder, figured those would work? terrylee

I've got one you're welcome to borrow... PM sent!

[terrylee]

Just want to thank Brian, he not only loaned me the flex hone tool I need but brought it to me! Know he said it gave him an excuse for a good ride. but I think it's above and beyond! This is the kind of people on this site.
Before he stopped by I did cleaned up my valves with a brass brush and drill and got them installed back in the head. Homemade tool worked great! Although keepers were fun to get back in. But not to bad once I figured how far to depress springs to get them to slide right in. Next is honing the cylinders, and once I get the rest of parts ordered, I will hopefully have it going in the near future! terrylee

[terrylee]

Last night tried to see if valves are seated tight. Installed spark plugs and filled each area with PB blaster (didn't want to use gas inside garage). Didn't show any signs of leaking for a while, but came back two hours later and some had leaked down into head area under valves. There was still about 3/4 of it that had not leaked out. Is this ok? I lightly lapped the valves and everything looked good on the valves and seats. Just not sure how long the valves should be able to hold back fluid? terrylee

[Nessism]

Last night tried to see if valves are seated tight. Installed spark plugs and filled each area with PB blaster (didn't want to use gas inside garage). Didn't show any signs of leaking for a while, but came back two hours later and some had leaked down into head area under valves. There was still about 3/4 of it that had not leaked out. Is this ok? I lightly lapped the valves and everything looked good on the valves and seats. Just not sure how long the valves should be able to hold back fluid? terrylee

Sounds like par for the course. Not perfect, but useable.

[posplayr]

Just want to thank Brian, he not only loaned me the flex hone tool I need but brought it to me! Know he said it gave him an excuse for a good ride. but I think it's above and beyond! This is the kind of people on this site.
Before he stopped by I did cleaned up my valves with a brass brush and drill and got them installed back in the head. Homemade tool worked great! Although keepers were fun to get back in. But not to bad once I figured how far to depress springs to get them to slide right in. Next is honing the cylinders, and once I get the rest of parts ordered, I will hopefully have it going in the near future! terrylee

Use a little grease on the keepers makes it a lot easier to install. They stay in place much better as you release the compressor.

[terrylee]

Thanks Ed, was hoping to not have to take back apart and lap them more. But will do if think it will make a difference? Yeah finally remembered about grease after first two valves, you're right a lot easier that way. But there still seemed to be a spot where they would drop right in, if not just adjust the spring compressor a tad. It's a learning process, but I'm enjoying it! terrylee

[Nessism]

Lapping doesn't recondition the valve or seat, it just cleans them. The better method is the recut the seat and face the valves. Of course, you need tight valve guides to get the most out of this extra work and expense.

I bought a set of seat cutters and had fun doing my own "valve job" a while back. Found a guy to face the valves and they looked like new afterwards for a few bucks each. Valve stem clearance was okay but was prepared to do the guides too if necessary.

Honestly though, what you have done should be fine to freshen up the engine nicely. Should be good for 50k miles or more.

Keep going...

[terrylee]

Thanks again Ed, makes me feel better. Plan on deglazing my cylinders tomorrow thanks to Brian! If the parts dealer would only get my expensive head gasket here, I might have it done soon. Can't wait to see how it runs and to just be able to ride!!! terrylee