TOPIC:

kwak1261 wrote:

Kawboy wrote:
The primary cause assuming the main jets are stock is that because 2 and 3 are fed by the same carb, the float level is too low.

you sure about that John ?? did you mean 1 and 2 ?

He posted the pic of the spark plugs in his reply and if you look at it plugs 3 and 4 are white / lean.

Pretty sure he means 3 and 4.

kwak1261 wrote:

Kawboy wrote:
The primary cause assuming the main jets are stock is that because 2 and 3 are fed by the same carb, the float level is too low.

you sure about that John ?? did you mean 1 and 2 ?

Nice catch. What the hell was I thinking. Guess I should start counting on my fingers. You're correct KWAK, 3-4. (Well if nothing else I now know that "somebody's reading my posts)

Ledkz1300 wrote: Thanks Kawboy.

Whatever caused the plug on cylinder 1 to be wet and black has changed because after a little drive it is now whitish like the others.

I used the laser the laser heat gun. All of the cylinders except for number 4 and 6 are within 5-10 degrees of each other as measured at the pipes 1 cm below the collars. About 60 C. Number 4 (which is actually number 3 in the picture as it is reversed) is about 80C, while number 6 is about 40 C.... which is really weird because it is the bluest pipe by far.

I did this twice to get an average and it seems to be holding that way. It is not super accurate because 1 cm in difference in the measuring spot changes the temp by a few degrees.

So based on the white coloration, all of the cylinders are a bit leaner than they should be.

Despite the fact it looks like all cylinders are firing I still feel like there is a miss under load. The exhaust tone is just not completely right. Maybe I am imagining things? Acceleration seems a little rough at lower Rpm... under 4000. It smooths out above 5000.

I also hear an odd rattle pulling away at very low rpm. I remember the same sound from my old one many years ago. This bike also made the same rattle with its old engine in it.

If you're using your heat temp gun on the pipes and coming up with 40 - 80 C then you must be checking them just after starting and while the engine is warming up. The bluish on the pipes will be the result of temps up around the 700 F- 900F mark. The further down the pipes the blue runs, the hotter the cylinder is running. DG pipes will show a lot of blue compared to stock pipes because the stock pipes are a dual walled pipe. the inner pipe carries the majority of the heat while the outer pipe only sees the radiant heat from exposure to the inner pipe. That bluing effect is happening after running at moderate load to high load. If you want to understand what's happening in the engine, take the bike out for a rip down the road and then pull over on the side of the road and check the pipes with your heat detector. You'll probably see upwards of 1,000-1,100 degrees F

I just pulled this from a welding sight. The discoloration of stainless pipe and the required temperatures to achieve the different colors. Being a welder in the past, we used to keep an eye on the discoloration during a weld out because the Chromium would parcipatate out of the stainless if you continued to weld at elevated temperatures. It was an undesirable property of stainless since when the chromium came out of solution it would leave hardened particles in the welded area which would cause cracking of the weld under pressure.

Colour Formed Approx Temperature C pale yellow 290 straw yellow 340 dark yellow 370 brown 390 purple brown 420 dark purple 450 blue 540 dark blue 600

As for the noise at just off idle- I hate to be the guy to point his out, but someone should. It's probably the primary or secondary chain. If the idle gets smoothed out from a carb cleaning and balancing, then the rattle MAY disappear. In any event, it would be prudent to check the chains if for nothing else, to know what service life is left on them.

I'm scratching my head at that. I took measurements both after idling and then after taking it for a ride. The ambient temp her was 16C at the time but the gun still reads what it read. It is reading the surfaces in the garage at 16C. When I tested boiling water in a pot the water came up at 98C and the surface of the stove at 289. Makes no sense.

I read that excessive pipe bluing can happen due to exhaust blow by so I re-torqued the studs and they were all a little loose. The bluest cylinder was the worst so that may be a factor.

I also did a plug chop. Put it under hard load in 3rd gear, shut it down and coasted to the garage. Pulled all the plugs and they are all still grey/white. Maybe a hint of tan. Still a little lean.

That sound I was referring to was actually not at idle... its at low RPM... under 3000 and it is only once in a while usually when pulling away slowly. The rattle seems like it is coming from the top of the motor. As I mentioned... all of my KZ1300 made this sound... including the one I had in the 90s. It is almost like the clutch basket rattle but its not coming from the clutch basket. It almost sounds as if the cam chain is rubbing against the valve cover or something. I wish I could catch a recording and post it. Maybe my phone will work.

Well, the carbs have been stripped, cleaned and rebuilt. Solved all my other problems. It running very well on all six, all the time. Throttle response is great. No backfiring, no popping on deceleration. All except my idle is still too high and the throttle drops off too slow. Only after it is hot and has been driven for quite a while. Starts out perfect. Takes about 30 minutes or more depending on ambient temperature.

My friend says the pilot jets need to be bigger. He says this is a known issue with these types of carbs. The screws have been adjusted as far as they can be. They had to be set at 4 turns out right out of the gate, but once set it works fine until it gets hot. I used the pilot jets that came with the rebuild kit.. which were the same as what was already in it 47.5

Can I get bigger pilot jets anymore or will I have to drill them out?

I believe that a better move is to raise the needles a notch.

Bill