A Newbies Adventures in Maintenanceland!

Maybe it's here in this posting somewhere but have to ask just the same...

Carb sync to specifications?
This is pretty crucial otherwise you'll be chasing this jetting all over the place to compensate and you'll never truly get them dialed in.

Good point old man. The carbs are bench synched, but not vaccuum synched, yet. Today is going ot be nice and warm, so I am going for an extended ride tonight, hopefully at least an hour then change my oil, I will make an appointment with my local tech guy with some guages to do a vaccuum synch for me before I do anything else.

BTW: when you vaccuum synch do you adjust the misture screws to make all carbs equal? or do you adjust something else...

9am53 wrote:

BTW: when you vaccuum synch do you adjust the misture screws to make all carbs equal? or do you adjust something else...

Your adjusting the linkage that is outside (between) the carbs. The adjustment manipulates the throttle butterflies so that the exact same amount of vacuum pressure can be applied across all four cylinders.

Very important...

I took the bike out for a longer ride today, and it felt awesome to be out in the wind again!

Anyways, the little stumble at lower rpm seemed to be better this time around, and once the bike got warmed up it was nearly gone. BUT I am for sure lean in the low rpm's and at full throttle. When I release the throttle to slow down (and feel compression which I didn't feel at all last year ) I get popping out of the exhaust, and when the bike was nice and warm it would pop a little waiting at red lights. Would turning the mixture screws out another 1/4 turn maybe help this? The screws are already out 3.5 turns, would maybe a one size up pilot jet be better? I found the mid throttle response was amazing, but once I really opened it up it seemed a little lean too...I ordered some 135 mikuni jets since I thought the DJ138 jets would be too lean, so I will swap those. I also realized that I for sure need a baffle, I have just the kerker endcap on my exhaust and I can't deal with it. At full throttle the bike just sings , but at mid throttle cruising it is just too much. Would a 1.5 inch baffle maybe richen things up a bit too? I looked at my plugs and the electrodes are white...

P.S. I took her out today for about 60 km's, (maybe 35 miles) and she didn't leak anywhere and the new seat is a lazyboy...I am way too pampered now! lol Also, I am glad I am getting the superbike bars because the drag bars are not as comfy to rode with as I thought originally...no biggie.

This is why I said to turn out your screws further...
You can turn them out further, but after 5 out it will make the fuel map "bumpy", and fuel circuit transitions will get erratic.

Go 1 up on the pilots.
Yes, you need a baffle if you want to hear.
If your using anything less than 3/4 to WOT, your still on the Needle, not on the Main.

As for the mixture screws, they should be set properly.
Use either a vacuum guage or an external tachometer, and set for highest vac, or rpm.
Then you don't have fiddle with them any longer.
May as well get a couple vac guages from Princess Auto, since you'll need them to do the sync...

If you're impatient, just get the bike hot then continue to turn them all out till the idle stops rising.

The bike should pull much harder as you approach WOT. If it's not then your likely correct with your guess of leanness. The 135's will make a vast improvement.

Remember, if the bike is popping at lights, things are getting really hot. OK, for the most part if things still run smoothly, but it kills your oil. So the oil change is a good idea.

Ride-on!

Sounds good. I was a little confused regarding the mixture screws, I misunderstood and thought that after 3.5 turns things would get kind of wonky...

I am still a little confused though, you say:

"As for the mixture screws, they should be set properly.
Use either a vacuum guage or an external tachometer, and set for highest vac, or rpm. Then you don't have fiddle with them any longer."

How do you use gauges or an external tach to set the mixture screws, I thought gauges were for synching the vaccuum. Is turning the screws to set the idle mixture just an eyeball method? As usualy thanks and sorry for my ignorance.

When turning the mixture screws, your changing the air:fuel ratio at idle throttle input. There is a perfect ratio that is the ideal mixture for optimal combustion per cylinder. When you have the "just right" area of the mixture screw, that cylinder will be producing the most power possible.

Its like a pyramid of power! One side lean/weak, the other side rich/weak. Your trying to find the peak/best power.

The best idle mixture can be found using an accurate tach or sensitive vacuum guage because the point at which the mixture is producing the most power, the vacuum/rpm will achieve its highest reading.

The tricky thing with 4 cylinders is that they all work against and with eachother at the same time, making finding the perfect mixture settings difficult for the inexperienced at best.

You can usually find an area of best/highest reading on a tach/vac guage that will be about an entire turn or half of the mixture screws where the vac/rpm will be highest(with a good ignition). Then you can "play" the screws in that area, test running to see which just feels best.

The point of most power is naturally slightly richer than a perfect stoichometric ratio 14.7:1, which keeps things smooth and reliable and peppy at idle.

So... you set your mixture screws to produce the most power (individual setting for each cylinder).
Then, you use multiple vacuum/sync guages to balance the amount of your mixtures/power each cylinder is recieving to smooth out the engine.
Then you set your timing

Hope this helped!

Potential Disaster!

yup, just as I was getting excited to ride...

I put my #40 pilots and #135 mains in the bike today, took me all of half an hour. Took the bike out, fired right up, idled great. I put my jacket gloves and helmet on and took it out for a quick spin. Sitting at the first light I noticed a slight ticking sound. I let this go for about 5 or 10 seconds, I thought it was an exhaust leak, so I prepared to turn around back home to tighten up the headers. All of a sudden with a CLICK it shut off. I walked the bike out of the busy intersection into a parking lot and what do I find but my new APE tensioner is ALL the way OUT! :S Let me assure you I had this thing set and tight as a tiger, somehow it must have backed out. I am praying that since it happened while idling that maybe, hopefully the chain just skipped off the sprocket or something without damaging anything. I am going to drive out to my buddies place where all my tools are and grab my wrenches. I am going to have to take the valve cover off and (hopefully) fix this in my parking lot...thank god I am moving out soon. Wish me luck, I have no more money for new valves or anything.

You've got to be kidding right.... I mean seriously now....
:blink:

Dude, I only wish.

Now that I think about it though it seems unlikely that the chain would skip a tooth or jump off a sprocket, I remember how tight everything was up in the valve cover... hopefully it just got jammed in the back by where the tensioner goes. Like I said, pray that the kaw gods are smiling on me!

BTW, VHT sux my balls. I am going to have my header ceramic coated "chrome" as soon as I have some scratch. There is surface rust already showing up. Garbage.

ok, just got in. I remembered I had a spare box of wrenches in the back of my truck. In the off chance that things were not as bad as I initially feared I tried turning the tensioner in and turning the motor over by hand to see if everything felt ok. I got heckled by some pregnant hoebag and an old lady, but they can kiss my ass. After nearly 30 minutes of turning the tensioner in with tiny little 1/8 turns I finally got it tight again, then I proceeded to turn the motor over and everything felt good. I am not a gambling man, but I took a gamble and trusted my instincts that everything was back to normal, so I hit the started button. She fired right up, idled great, with no weirdness at all...everything seems to be good. I couldn't get her warm again and go for a ride because I had to finish dinner, but I have my thumbs crossed that things are ok.

theres a cure for that,its called the factory tensioner .they work suprising well for 99% of the bikes out there! :laugh: