My Valves and Pistons - Feedback Please

I do use a gas additive.
I use a blend of Lucas Gas treatment and Seafoam. The blend is 1.5oz Lucas and 1/3oz Seafoam per Gallon of Gas. I looked inside my combustion chambers with a bore scope and it is beautifully clean. I don't think that I have 5% of the muck as shown in the previous pictures. I personally run only BP Ammoco. Regular in the 900 and in the GPz1100, a blend of Premium (BP) with 1 gallon out of five 100LL Aviation gas and 1 Naphthalene ball per 3 gallons of fuel plus the same additive package. I also noticed something interesting in the combustion chamber pictures posted in this thread. Some of the plugs seam to be too short. I don't think that they are screwed out some, because the threads underneath them are fouled. Is it possible that the plugs are incorrect or have too many washers under them?

Over the past summer I have cleaned the carbs numerous times and all passages appear to be clean. However, as Patton suggested, I'll get new pilots just be sure.

Wouldn't bad choke plunger sealing only affect things once the choke was down? Meaning it wouldn't have any affect on the cold starting issue?

As for gas, I'm just using regular octane 87. I occasionally put in a bit of Seafoam. However, this is my first year with the bike, and I don't really know the history.

As for the plugs appearing short, I backed them out a bit before removing the head so that it'd be easier one I got it off. Good eyes though guys. With that said, I'll seat them in fully before replacing the head to make sure they extend into the chamber the correct distance.

Thanks

Gonna take a chance and speculate a little bit here. :lol:

Am thinking the cold starting issue was over-enrichment causing the #1/2 plugs to fuel foul until later self-cleared when engine warmed. And this resulted from a too rich pilot circuit mixture imposed onto the enrichener circuit. Could explain why it started fine on the choke but then quickly died unless given some throttle (which diminished effect of enrichener circuit), and temporary backfing was burning off the excess fuel.

Would say YES the over-black flakes are a sign of overly rich state.

Would say NO the #1 exhaust being a different colour is not anything to be concerned about.

Although cold compression figures are good, over-tight valve clearance may result in loss of compression upon reaching normal operating temperature (thus poorer combustion).

For reference, am thinking the factory specified valve clearance is 0.08 - 0.18 mm (0.003 - 0.007 inch).

Once all valve clearances are to specs, compression may be dismissed as a suspect imo, leaving ignition and carbs as the remaining suspects.

Ignition may or may not have been weak, with culprits being anything from coils, plug wires, caps, plugs, points, condensers, wiring, connectors, battery, etc. The new Dyna-S ignition, Dyna green coils and Dyna solid core plug wires should resolve any pre-existing issues between coils and plug spark.

But should still consider assuring full positive battery voltage is reaching the coil primary terminals. For even the vaunted Dyna components can't compensate for insufficient voltage.

As known, even perfect carbs can't compensate for weak spark, or improperly timed spark, or poor compression at normal operating temperature.

Imo, you're on the right course.

The peanut gallery has now spoken -- but I don't get asked to clean any chaulk boards either.

Good Luck!

Thanks Patton, appreciate the detail in your response. Good speculation on the cold starting problem, you're reasoning makes sense to me.

I guess I'll proceed with cleaning and reshimming the valves, clean the piston tops, new pilots, ignition system and see where I am then come spring. I can't start or run the bike until probably April anyway. These tasks should keep me busy until then

I'll also go through the carbs again and also ensure float levels are correct.

Forgot to mention in my earlier post but I've done the WG Coil mod, timing has been checked and carbs were vacuum sync'd.

Thanks again.

One last question though. Since I have the head sitting on my workbench now, can I test for leaking valve seals by putting some oil on top and then checking in the morning for leaks? I haven't touched any of the valves yet.

A light oil/Kerosene will work well checking for valve seat problems.Fill it and check in the morning. This will certainly prove real quick what needs work.

Excellent, thanks MFolks. I'll give that a try tonight.

now that you have the head off, why not dissassemble it ?
you came this far, might as well clean the carbon off the stems, lap the valves, replace the valve seals and possiblly replace the exhaust guides. then you can also install some ape springs.
just a thought.

Yes kawasakiman, that has been my plan all along. I just wanted some input on the condition of everything before I started working on it. I'll be doing all you stated with the exception of the springs. Just not in my budget this time around

HerrDeacon wrote:

Over the past summer I have cleaned the carbs numerous times and all passages appear to be clean. However, as Patton suggested, I'll get new pilots just be sure.

If I understand: you had a motor that ran bad cold until you added choke and then it ran better... then ran OK warm?

That could not be anything BUT carburetor or intake leak problems. If it was valves, rings, head gasket, etc, adding choke would not improve it. If you have wasted a large amount of time on the carbs, you may want to send them to wiredgeorge for rebuild because they will come back working perfectly.

HerrDeacon wrote:

Yes kawasakiman, that has been my plan all along. I just wanted some input on the condition of everything before I started working on it. I'll be doing all you stated with the exception of the springs. Just not in my budget this time around

The valves and pistons in yours look WAYYYY better than mine did when I tore it down. There is no burned oil residue from valve seals letting oil leak down and in. They look pretty good to me. Your compression readings look fantastic.

With the excellent compression figures, would be surprised if there's any leakage through the seat when the valve is closed. Unless maybe a little speck of the excessive carbon buildup has made its way into the seat under the valve face, which imo wouldn't be anything to worry about.

Good Luck!

P.S. Where the heck is timebomb anyhow? Thinking he is surely poised at the ready with freshly sharpened red pencil, and throwing his body between us and the chalkboard. :lol:

bountyhunter wrote:

If I understand: you had a motor that ran bad cold until you added choke and then it ran better... then ran OK warm?

That could not be anything BUT carburetor or intake leak problems. If it was valves, rings, head gasket, etc, adding choke would not improve it. If you have wasted a large amount of time on the carbs, you may want to send them to wiredgeorge for rebuild because they will come back working perfectly.

Actually, my problem was it would start first kick, but then a second later would start to die unless I gave it a bit of throttle. I would then take it off the choke, and you would hear the exhaust pop as the dead cylinder would kick in. Once warm it ran great. So, the choke in my problem never helped any.

Thanks for telling me that they don't look too bad, thats encouraging for me. This is my first time opening up an engine so I'm a bit of a noob when it comes for things to notice or look out for. So do you even think I should replace the seals at this point if it doesn't appear that oil has been leaking down?