Lifespan of head to carb boots.

I use an airbox, and my boots were replaced 3 years ago. They have about 6,000 miles on them.

How long do these things last?

I just did a valve check and cyl 3 was tighter than the other three, but still in spec. Last summer, I had problems getting this cylinder to sync. It's spark plug looked slighter leaner than the other 3 but was still tan in color. I did an ether and WD40 test of the boots and the idle didn't change.

It seems to me that this cylinder was running lean to account for the different valve lash and a vacuum leak could account for the sync problems.

I am asking because I am switching to pods and I don't want any problems.

The carb to cylinder head "carb holders" last many years before needing to be replaced when an airbox is used. I replaced my originals after 28 years because they were leaking air. That was 11 years ago and the replacements still do not leak at all. Using pods without additional support for the weight of the carbs may change that depending on where you ride. Of course, switching to pods is very likely to cause other problems unrelated to the carb holders. Ed

650ed wrote: Of course, switching to pods is very likely to cause other problems unrelated to the carb holders. Ed

I've done a lot of reading and it appears that TK22 carbs will work with pods.

Despite my best efforts (fuel filters and stabilized fuel) I still end up ripping out the carbs at least once a year. I am sick and tired of fighting the boots on each side of the carb rack.

The_Proletariat wrote: Despite my best efforts (fuel filters and stabilized fuel) I still end up ripping out the carbs at least once a year. I am sick and tired of fighting the boots on each side of the carb rack.

Holy cow; that would be a pain! In 39 years I have removed my carbs 2 times. Once in 1989 because I let the bike sit too long with fuel in them and it formed varnish and once 11 years ago to replace to replace the carb holders. What causes you to need to remove yours so often? Is it to clean them after they sit for an extended period? After that happened to me the one time I never let the bike sit more than one to two weeks without starting it. I do that during the winter and it prevents any varnish from forming even without using Sta-Bil or other fuel stabilizers (plus it keeps the battery charged and oil on the cylinder walls, cams, etc.). Ed

I've never used any fuel stabilizer in over 30 years. If you drain the carbs every winter, there is no fuel that needs stabilizing in the carbs. I try to keep the tank full all winter to prevent water accumulation. But the carbs, I leave empty if I remember to drain after the last ride before snow.

But really, I have often let the bike sit with fuel in the carbs for months at a time (when I'm focusing on a different bike) and haven't really had an issue with gumming etc. Every now and then, after a long ride, or a series of riding several days in a row, I'll drain the carbs. The fresh gas from riding might dissolve whatever is in there, and then draining it will get rid of it.

Whatever you do, don't throw away the airbox and boots. If you don't want them, someone else eventually will.

Oh, and on the lifespan, I had 25 year old carb holders used with pods for 7 or 8 years. I did eventually replace them, but they were 33 years old by then.

I removed 3 years ago to see what shape they were in as the bike would barely idle.

I removed them multiple times last year because debris from the gas tank was passing the petcock strainer and inline filter and clogging up the carb vent tubes.

I need to remove the rack this year because carb #4 bowl drain screw o ring is rotted away. I would like to see what else happened in there over the winter. I have a feeling there is more damage because it wouldn't start.

I have considered draining the system in the fall but I fear the carb-to-carb o rings in the rack would deteriorate if they are dry for months at a time.

Have you considered simply running the bike for 10 - 15 minutes once a week during the winter? That works for me. Ed

I have at least 2 months of the year when I feel lucky if the high is 20 degrees. Entire weeks can be in the single digits. I would be shocked if this bike starts at that temperature.

That being said, I will attempt your method this winter.

We have a pretty long, cold winter here too, but I've always been able to start my bike; I then let it run until I can feel the mufflers getting pretty warm - usually less than 15 minutes. Sometimes I do use my kickstarter though, so in that respect the 1977 KZ650 may have an advantage over later models. I suspect if you are able to keep your bike's battery on a battery tender you will be able to start the bike without much trouble. That works really well for me on a antique convertible car I rarely drive in the winter but start each week. Ed