1100E rebuild valves

[gggGary]

1982 GS1100E 31K on the clock, I bought it "barn fresh" Never tried to start it except for a couple of shots of ether, popped a couple of times. Carbs off on the starter I got 20, 110, 105, 110 lbs. With air on #1, the intake valves were leaking bad. I debated for a while, do the carbs, fire it up and see what happens? But I decided that cylinder was SOO low I better pull the head. So here are the #1 intake valves and seats. Anyone want to give me an idea, should I clean and lap em and see if they will seal? What about the cleaning do I wire wheel em? something other method? The bores look good I haven't pulled the cylinders but will and will see how everything looks. I figure on putting in the gasket set from Z1 ent or similar. I will probably reuse the rings.

Bike is decent stock condition, all stock pipes, air box (K&N filter) Not after perfection here just an old bomber bike that runs decent, I still have to spring for new tires, chain, sprockets, brakes. Thanks for any help

[Nessism]

Those valves look kind of iffy. I'd clean them up a little and check the faces for pitting, seats too. A small amount of pitting can be removed with lapping but not a lot. I'd also check the valve to guide clearance; install the valve in its matching hole, hold it open about .3" and see how much the valve head wobbles. If you have a have a dial indicator measure how much wobble. The service manual lists the spec. Too much clearance means the valve won't seal properly, or for very long, so you are looking at new guides.

[gearhead13]

I tried lapping valves that were in better shape than that and ended up ruining them, had to buy new valves. A decent machine shop could tell you if they are too far gone. 20 is still pretty low for even those, did you check the valve lash before the compression test?

[gggGary]

I did set clearances and reran the compression, the heads were full of carbon junk I figured (hoped) that was what was keeping the valves from sealing. Good idea I will put a dial indicator on em and see how the stems/ guides are.

[Nessism]

This shot are for an 8 valve engine but you should be able to get the idea.

[rapidray]

Clean the valves on a wire wheel, lap them in & look at the valve faces & seats. I'll bet you have usable parts. Call me at 714-356-7845 if you want some help. Ray.

[SqDancerLynn1]

Since you took it apart I would do the valves, He's offered so Ask Ray if you need help. Do a cyl hone and new rings too..

[gggGary]

Point taken, 'll pull, clean and lap all the valves, new valve seals.

[chef1366]

If you need valves I have a box full of good ones.

[gggGary]

Nessism you really scared me; I started checking valve to guide tolerance and was way wide of what your picture shows, then I went to the 16 valve manual and the service limit is .35mm (.014") The intakes are about .005" but the exhaust are are out around .010-.012" Just checked #1 so far but I will check them all later. I am still trying to get a good procedure set up to do this well.
Thanks for the call offer Ray, I'm keeping my powder dry for a bit yet. Anyone want to bite on lapping techniques? There seems to be a bunch of different ideas on that. Thanks for all the responses so far.

[Steve]

Anyone want to bite on lapping techniques? There seems to be a bunch of different ideas on that. Thanks for all the responses so far.

The technique that I used was to fit a bit of rubber hose (I think it was a piece of breather hose) over a bolt that was chucked into my cordless drill. I placed the head upside down on my table saw and had the extension pulled out so it would support the end of the head and I could reach up inside the gap to reach the two inner sets of valves. To do #1 and #4, I just hung the end of the head over the edge of the saw table. I made sure the end of the hose was rather square, then put a bit of lapping compound on the valve seat, stuck the valve through the guide, then lifted the valve head off the seat just a bit with my finger on the end of the valve and applied the drill and rubber hose to rotate it. I had to control the seating pressure with my finger on the end of the stem, as it took too much pressure with the drill to get enough friction to rotate the valve. It worked beautifully and quickly. Might have taken about 5 seconds of spinning (low speed, about 400 rpm), the seats looked great and the valves had that perfect 1 mm band of "clean" all the way around.

Now, for all of you more-experienced engine builders ... is there any reason I should NOT do that?

It just worked so well, I'd hate to not be able to do it again.

.

[rapidray]

Anything more speed than what you can rotate by hand can actually remove a LOT of seat material quickly. I learned in my Dad's race shop as a kid using the suction cup method & I think, for someone learning, that is still the best way. What I do now is use a tap handle, clamp it to the valve stem & rotate the valve with the tap handle while putting slight downward pressure to the valve head. This works very well for me & makes the job MUCH quicker than the suction cup tools. I would NOT use a power tool for lapping valves, the lapping compound is just too coarse. Ray.

[chef1366]

I use a vacuum hose on the end of the valve and run it back and forth between my palms.

[hampshirehog]

I'm a suction cup man as well and have always been concerned like Ray that using a power drill will remove too much too quickly. Sure, it's a slow, boring job spinning by hand but it's a whole lot faster than boogering things up and having to get new seats etc. if you get it wrong.

Quite a few shops over here will go with drills to speed things up where they're chasing the penny but I've seen some pretty poor jobs as a result.

BTW, I reckon Suzuki were pretty conservative with the guide to valve stem tolerances - I've seen some heads way past their sell by date that came off bikes running well. Your numbers look fine.

[gggGary]

Got the valves out and checked the stem guide clearances.



here are the numbers I got.
the intakes are all between .004" and .007" so no worries there
2 & 3 exhaust are all .007 to .008" so that's still well with in service limits.
1,4 exhaust are .011, .011,.009, .010 that's getting up there service limit is .015"
So those are the ones I am on the bubble over, the stems all measured and appear fine. The wobble is noticeably perpendicular to the cam as one might expect. I did not do any inside checks on the guides but will probably do that too. So the $64,000 question is do I replace the exhaust guides on 1 & 4? If so Suzuki or APE guides and is this a DIY project? Thanks for the lapping ideas, by hand with a rubber tube and dowel for 15 to 30 seconds seems to be about the idea. The valves and guides cleaned up pretty good and should lap in, might be close getting the rough spots out on a couple of the exhaust valves.