TOPIC:

hillsy wrote:

Yaegunp wrote: I am trying to work out if I have to go deeper into the engine to establish root cause(s).

I don't think there's anything in the bottom end that will need attention for your carbon problem, however, you have disturbed the base gasket now and you should replace that (or else oil leaks will be likely). And anyway, you should clean up those pistons tops while you're here.

Hi Hillsy, When you say base gasket does that mean removing the next level down to the crankcase and replacing that gasket?

Cheers

The red arrows show where the coolant is starting to leak through. It doesn't need much but a bit longer and it would have been oil in the water

The black stuff is coming from the exhaust ports because of the passages that lead to the port for the crazy US polution regs. It's nothing to be concerned about as the reed valves and smog plates aren't there. It should not have any effect on fuel mixture.
Those bores are very shiny I would consider a set of rings and a hone if you can see to it. Not 100% necessary at all but helpful for maintaining optimum performance

Just some thoughts Paul-

The soot issue/carbon buildup- Normally I would check off the high carbon build up to shitty gasoline. Cheap fuel tends to burn and leave excess amounts of carbon build up. The fact that you have the secondary fuel system and started using it again leads me to believe that the fuel in the secondary tank is old and by old I mean any fuel that's been sitting for more than 6 weeks is now considered old because of the ethanol blend. If you plan on fueling up and "storing" fuel for periods longer than 6 weeks, you need to add fuel additive specifically for ethanol fuel. It will help maintain the "freshness" in the fuel.

You're compression reading with #3 being low- Due to the fact that you had a coolant leak and #3 got the combustion chamber and piston top cleaned off of carbon, the compression would be lower than the other cylinders which have a high build up of carbon. I could easily justify a 20 psi difference just due to the differences in the build up of carbon. Do you need to tear down the cylinder and do a ring job? Probably not. I would hazard to guess that if you cleaned up the combustion chambers and piston tops and reassembled with a new head gasket, the compression would probably end up around 135-140 psi across the board. Judging by the carbon buildup on the valve seats, there was some leakage there. You were due for a valve job. Evidence of valve stem seal leakage is visible in your pics by the shiny black around the valve guides.

You're secondary fuel system could be problematic. Not knowing how it feeds the carbs leaves me in the dark so I'll throw out some thoughts here. On a standard setup with gravity fed fuel from a standard fuel tank- the "fuel pressure" is around 1/2 psi due to the gravity effect. When the carb floats are setup the maximum amount of "lift" the floats must provide to shut off the fuel is related to the pressure from the fuel. If your secondary fuel is setup so that you shut off the fuel line from the main tank and then provide fuel to the carbs from the secondary tank at say 5 psi, the fuel level in the carbs may be higher depending on how much "lift" the floats can provide. If the pressure in the secondary system is higher than the main system, then the carbs may not compensate for the difference.
I would consider replumbing the secondary system so that it "transfers " the fuel from the secondary tank to the main tank via a switch that you turn on. Then when the fuel in the main tank comes up to near full, you turn off the secondary pump.

The soot in the cylinder head ports from the exhaust gas recirculate system- I suspect that your blanking plates in the valve cover are not sealing properly and you have exhaust gases from a couple of the EGR ports pushing backwards down through the ports and into the crankcase. Pop the cover plates off of the valve cover and check. You don't need exhaust gases returning to the crankcase.

Yaegunp wrote:

Ledkz1300 wrote: I also would not blame the secondary tank and pump. As Hillsy said, your floats still meter the amount of fuel being delivered by that carbs. The carbon buildup screams rich to me. With that much carbon buildup I'm surprised your plugs weren't fouling as it looks like it was running very rich. However, it could be over a long period of time.

Of course they are fouling and it has me miffed. As I said colortuned and the screw adjustments are between 2.5 and 1.5 turns, nowhere near the 3.5 suggested turns. I have a newish K&N filter installed with only a few hundred miles on it.

Ledkz1300 wrote: What color are your plugs? Are they black and sooty like the combustion chambers?

Some are black and sooty others are the tan color.

Ledkz1300 wrote: I did a lot of driving and adjusting to get my carbs set so they weren't too rich or lean. Drive for a bit, pull the plugs, examine the color, make a 1/2 turn adjustment on the mixture screws and drive some more. Repeat until I got it right. Plugs a very light tan color, no soot buildup.

I started doing the exact same process as you when I noticed the ticking noise and of course the rest of the story is history.

Ledkz1300 wrote: The black on the edges look like the remainder of your head gasket.

If you're referring to my question in the video at the 48 second mark then that material goes all the way down those journals and even goes up into the corresponding holes on the cylinder head cover, so I don't think it is gasket.

Not sure what you are running for an exhaust and jets but if you've changed from stock your jets could be making things too rich. As hillsy said you can change your needle settings and/or jets. Altitude can greatly affect this. I live at sea level and if you are at say 2000 feet than my setup would be different than yours.

Since you've used the colortune to adjust your mixture you are going to be good at idle but clearly something is amiss at riding RPMs since some of your plugs are black.

The air mixture screws affect from idle to about 1/4 throttle, so depending on your riding style adjustments here can impact a large chunk of your riding. The only real way is to drive it, pull the plugs cylinder by cylinder and adjust accordingly. Its a pain in the ass but I don't know of any other way unless you happen to have a dyno and an exhaust probe. I would say most of your adjustment can be managed this way.

The needle jet controls fuel from 1/4 to 3/4 throttle. Adjusting the clip changes how much fuel gets drawn in the venturi in this range. If the engine needs to be leaner the clip should be higher. This allows the needle to drop further and less fuel gets by. A pain in the ass to set since the carbs have to come off.

The main jet controls fuel at 3/4 throttle to WOT. The only thing you can do here is change the size of the main jet. Unless you are running it at WOT I probably wouldn't worry about changing this for now. I'd guess that most of your throttle is spent between zero and 3/4. Even though I run fast and hard my RPMS come up damn fast so I rarely need to open the throttle all the way.

This is all predicated on your float levels being correct because if they are messed up than it will throw everything else out of whack. Good plugs, wires and good coils is also assumed.

I don't know what you run for fuel but it should always be the highest octane you can buy. In our neck of the woods, super which is 91 octane supposedly has NO ethanol so this is what I always run in my small engines. old motors, or motorcycles. My old van runs like shit on regular or mid grade so I wouldn't dream of putting it in my bikes.

LEDKZ1300 understands how to set up carbs !! Nice !! Great explanation Bud.

Quote LEDKZ1300
"I don't know what you run for fuel but it should always be the highest octane you can buy. In our neck of the woods, super which is 91 octane supposedly has NO ethanol so this is what I always run in my small engines. old motors, or motorcycles."
In Australia the cheap crappy fuel is known as 91 and comes with or without 10% ethanol. This is because of a different way it is measured.
Our good stuff is 98 and I use nothing else, I even use it in my lawn mower and Chain Saw.
Because of the different way we measure octane/RON/whatever it can cause lots of confusion and often does.
And Don't ask me why it's done that way. Its not Aussies that are strange it's the rest of the world.