Contradictory

So after an abnormally short and warm winter I finally got my bike back out on the road. One stretch of highway later it was obvious something was amiss. IN every gear, from half to full throttle was very hesitant and jumpy. If I eased on the throttle it helped, but if I ever tried to punch it quick, it really lagged. I started reading around and it sounded like this was due to running lean. But when I took off my plugs they were black as night which suggests running rich. I removed the carbs to see if they were out of whack and might need adjusting. I thought I might benefit from re-jetting my carbs and after talking with the folks at the local motorcycle shop, I decided it would probably be the most inexpensive troubleshooting to do...so I replaced my set of 125 jets with 120's on the outer carbs and 122.5 on the inners. I rode it and it seemed to be a little better, but then again I could just be hopeful and deluded. :laugh:
I guess my question is...first, anybody have any suggestions? Second: should I go smaller on the jets? Or do you all think that is futile?
Thanks
OH...BTW: I'm on a 78 police KZ1000 with open air K&N filters and with no muffler. Haha

also, I seem to have started to get a little oil in my exhaust...is that just part of getting older?

Post edited by: Bicycle Lee, at: 2007/03/26 23:40

If you left fuel sitting in the carbs (all it takes is a few weeks), and especially without using some kind of fuel stabilizer like Stabil, it's likely that the gas has gone bad and the carbs are gummed up slightly.

Try this.
Hook up a clear hose to a drain bowl screw on one of the carbs and put the other end into a cup/bottle/can/etc, then back the drain screw out until it drains some fuel into the container.
If the fuel smells and/or looks even a little funky (usually a dark brown/orange and smells like turpentine), it's gone bad, and a good old fashioned removal and thorough cleaning of the carbs is in order. :pinch:

I'd say ok, but my first project (which I guess I should have disclosed before) was resealing my tank. It had some rust and crap built up and my carbs weren't getting clean fuel. So they're now getting clean fuel and they have been cleaned since. I pulled off the wells to redo the jets and they didn't have any gunk or rust in them. One other thing I found was that the slides inside of the carbs aren't seated extremely tightly. Seeing as how they are expensive, I figured I'd try to find a cheap fix first. Haha

Bad fuel won't always make itself apparent in the float bowls, especially if it has been mixed with known-good fuel and/or the old fuel has been run out of the tank and carbs.
It's the jets, float seats and teensy weensy inner passages of the carbs that will become clogged, or slightly clogged.
Sort of like the blood flow in a persons arteries clogging up before the ol' ticker itself becomes clogged.

Something you mentioned made me think (ouch?) of another possible problem though.
It could be possible that some of the sealant that you used to coat the tank has "chunked" off and is partially blocking the petcock screen on the inside of the fuel tank.

You wouldn't be the first person that this has happened to. :pinch:

true...that COULD be a possibilty. I know I need a new petcock anyway. Mayeb I'll just replace that guy while I'm at it

The 78 cop bike had pretty much the same carbs as the standard that year. The C1 model and the A2 model had the same jetting and the C1A and the A2A had the same jetting. The C1/A2 was jetted lean and got much leaner with the A2A.

Your symptoms indicate incomplete combustion. Read both tech tips on our website under the "wg's Tech Stuff Index" for valve clearance adjustment and coil repowering. Next clean your K&N pods.. wash them out with K&N cleaner and very lightly re-oil according to their instructions. Since you didn't mention your airbox but in the private note you sent me, mentioned "open air K&N filters" which I am guessing means pods... Your bike started life with #102.5 main jets and either #17.5 or #15 pilots. Since you have a noisy muffler and pods, try #112.5 mains, #20 pilots and clip to the 3rd slot... think you have 5DL31 jet needles so it will be 5DL31-3. Noted you were at 4500 ft. in your private note to me. Changing up the jetting... #112.5 mains, #17.5 pilots and 5DL31-3...

If you need further help and I am not on the board, please drop by our vintage bike tech forum linked off our homepage. I visit that forum more often. thanks

Post edited by: wiredgeorge, at: 2007/03/27 15:25

Post edited by: wiredgeorge, at: 2007/03/27 15:58

If everything was fine with the carbs before and they are clean, then it's NOT the carbs. If fine before, it's certainly not the jetting(aside form any constriction as a result of CRAP).

Make sure you have fresh fuel and adequate fuel flow from the tank. Unhook the fuel hose and see how long it takes to drain a pint. Watch that the flow rate does not decrease by timing first and second cups.

-Duck

Duck, his main jets are MUCHO big for his bike and the altitude. He needs to rejet. I have already suggested cleaning airfilters and doing normal tune up stuff which probably contributes to the problem but the mains are definitely problem sized...

what did i miss? he mentioned nothing as far as i could read that the bike ran poorly BEFORE he stored it? so in my thinking if thats true. doesn't it make sense that the issue is somehow fuel related? NOT jet size etc. If it ran good before with the same jets as it was stored with, I am thinking it should run no different now, unless his carbs./fuel has contamination issues.
Just my 2 cents......LOLThis may sound strange but...check all your fuel dilery as well as vent lines for spider webs and the such! seen that happen more than 1 or 2 times!
GOOD LUCK

Well, I guess I should have elaborated further...
I bought this bike back in september and it has never really ran "right". The clutch was shot, carbs were full of gunk, tank was rusted, petcock was tempermental....I think the farthest I rode it without it dying was twenty miles...
Over the winter, I cleaned the carbs, sealed the tank, and fixed my fuel delivery issues. Now that all that was out of the way I really got a chance to ride it. Took it on I-80 west for about 45 miles and noticed that throttle issue I had mentioned before. I had noticed something similar the previous fall, but thought it was all due to the fuel problem...now that that was taken care of I had narrowed down the suspects. Looked into carb problems and thought rejetting sounded like a good start. If WG says the ones I have NOW are too large, then the ones I had before were CERTAINLY too large.

Post edited by: Bicycle Lee, at: 2007/03/28 12:29

is there any online tutorial for removing the pilot jets and checking their size?
I'll probably run the 112.5 on the inner carbs and 110's on the outer, since the inner ones burn hotter anyway