Please Help Me... I'm New Here !!!!

[zoro]

Its a labor of love!

[Newbie_3131]

ok, here's the deal, I went yesterday to finish up the wiring on the new headlight, i wanted to tuck those wires neatly, tried to start the bike and had a really really hard time, when she finally started, she was in backfiring pretty bad, at some point you could see blue flames shooting out of the tailpipe.... I went back today and i tried, and tried, and tried, then tried some more, and was not able to get it started, again, the colder the ambient temp, the harder the start, the backfiring (and the flames coming out of the tailpipe) make me think I am probably too high on the needle (too rich) I know somebody said before hard cold starts are probably lean mixture but from what I can tell its even harder to start with the choke up (which I think means enrichening the mixture makes matters worse) 1 more thing: when I first crank it after being off overnight, it sounds like she 's about to grab, then it's all downhill from there. SO, I went up 1 slot on the needle, then placed 1 washer under the clip, my thought is to go in and remove the washer...

[StarGate]

It's a bit blurry but still looks to be running way too rich. That would also explain the blue flames out the exhaust as unburnt gas that is getting into the exhaust gets ignited.

[zoro]

Originally Posted by Newbie_3131

ok, here's the deal, I went yesterday to finish up the wiring on the new headlight, i wanted to tuck those wires neatly, tried to start the bike and had a really really hard time, when she finally started, she was in backfiring pretty bad, at some point you could see blue flames shooting out of the tailpipe.... I went back today and i tried, and tried, and tried, then tried some more, and was not able to get it started, again, the colder the ambient temp, the harder the start, the backfiring (and the flames coming out of the tailpipe) make me think I am probably too high on the needle (too rich) I know somebody said before hard cold starts are probably lean mixture but from what I can tell its even harder to start with the choke up (which I think means enrichening the mixture makes matters worse) 1 more thing: when I first crank it after being off overnight, it sounds like she 's about to grab, then it's all downhill from there. SO, I went up 1 slot on the needle, then placed 1 washer under the clip, my thought is to go in and remove the washer...

I agree with StarGate, its definitely "looks" rich and your thinking correctly in that the engine seems to be flooding out at "start up." I also agree that your needles too high.If thats a "dynajet" 6-slot needle, put the e-clip in the 3rd slot "without" the washer since youve already increased your jet size by 2. If its a 5-slot needle, put the e-clip in the 3rd slot without the washer.Be a bit conservative on your initial settings! Now then Im going to drop a bomb. That needle and that main needle jet dont have anything to do with start up and idle! The pilot and the enrichener/choke circuits are solely responsible for fuel delivery at start up. These old Kawasaki engines are "Notoriously" cold blooded! On a 80+ degree day my bike starts immeadiatly, and 50deg. or lower I have to use full choke and two or three 10-15 second attempts on the button before she fires!(It makes me wonder before she hits!)Once warmed up she runs strong no hickups! Untill shes up to temp, she runs like a sick dog! Heres something you need to keep in mind, none of these bikes will start or run right if the you dont have a strong fat spark at start up and during low idle. That fat spark needs to originate from a strong fully charged battery delivering at least 12 volts to those coils. A weak spark can have you chasing phantoms in the carbs! One more thing to look at is the air mixture screws, try 1 turn out from lightly seated to lean out the pilot circuit and you may have to go as far as 1/4 to 1/2 turn out to see if thats favoring an easier start. I think those carbs have been jetted before and the previous owner may have installed pilot jets intended for the dragstrip instead of the street meaning theyre too big for putting around. Whatever you do dont get discouraged! We all went through this same sh1t your learning now, Kawpauls going through it too! Your very close, these Kaws dont come easy! Your doing fine, keep it up!

[Newbie_3131]

well, thanx. its good to know I'm not the only guy that ever pulled his hair out over this deal. I was quite convinced before I was too rich (like I said flames coming out of the tail pipe look kindda cool, but they kinda tell u something is up) I figured just like u guys said, The unburnt fuel getting to the exhaust system, now, these 5 slot needles were already set on the forth slot b4 i even touched it, with the pod filters and the baffle taking out I figured i needed at least 1 step up, but that needle could have been set in the wron slot to begin with... my thought was too just remove the washer and leave it in the 5th slot, but I'll take ur wisdom over my guess, as far as the air screw,I never saw one, somebody told me that it might be concealed to where I have to drill a rivet to remove some sort of cover plate. as far as the pilot jets I changed those remember? and my acceleration between 20 -75 % is good, I'm having a weak idle (feels like she's flooding) and rough full throttle (that actually feels like might be too rich too) remember i went 2 sizes on the main jet to 110 I'll deal w/ full throttle after I get it to idle and start properly

[kawpaul]

If your bike has the original carbs the air screw would be #42 in this pic. It may be under a plug in which case you will have to drill the plug out.

[Newbie_3131]

thnx Kawpaul that's a really good ilustration, I need to go check exactly what is going on there, I Believe I have new air screws, the low airflow caused by the screw being too far in explains all the problems I'm having now, I was under the impression that removing the baffle and installing the pod filters would automatically increase the air flow thru the carbs (and to a certain extent I'm sure it has) but I was unaware the flow could/should be adjusted/increased to compensate for the bigger jets and needle adjustment. I will look at that as soon as I get a chance and post update later. by the way, I thought it would be good to let u guys look at an actual pic of the carbs: this is before i cleaned them

[Newbie_3131]

OK, here we go; This is long. and not good, I'll try to be as clear as possible and include any details that might seem relevant, as best I can recall. bike still won't start:
- I began (after another failed attempt to start the bike) by changing the air screws and springs, seated them gently then backed off on each one, i noted before removing them that they were about 3 turns out from the seated position before i took them out. I went anywhere from 1/2 all the way to 3 turns out from seated position making several attempts to start along the way, and increasing/lowering at 1/2 turn intervals bike never started,. at all times connected to a car with jumper cables
- Having agreed that the needle was probably set too high, and the engine was probably running too rich (flooding) at the top of the throttle, I went ahead removing the carbs from the bike, set the 5-slot needle clip on the 3rd slot, put the top of the carbs back together. Remember, bike never started today, or last time i tried. the last time I actually rode the bike, it felt like it was flooding at idle, choking if you will, i had to over-rev to take off
- From what i could tell, the bike was running too rich at idle, and doesn't start, the strong smell of gas makes me think i might be flooding, and I have tried all over that air screw, so I took the bottom of the carbs apart, and actually removed that larger pilot yet (20), and replaced it with a new (original sized 15) pilot, remember, no baffle only end cap on the tail pipe, put all back together, still no start, choke up, choke down, no start.
- once again I went all over the place with that air screw, in small increments, uniformly in all four carbs, no start.
- Placed in line spark plug tester to verify power to the plugs. ok.
- Unable to start, and quite aggravated, took the spark plugs out, cleaned them with a wire brush and sandpaper (even though i just put them on) put it all back together, cranked, she almost fired once or twice but couldn't grab then went back to square one. here is what I think: (not that it matters much) I think when I took the spark plugs out, I gave the cylinders some time and air to dry out, so the very next time I tried to start it she almost grabbed, until she flooded again, what I believe at this point is that I might have a Vacuum leak some where. but I could be way off track here.
- One more thing, when I took all the plugs out, the 2 on the left side were actually wet with gas, i could see the gas on them, the ones on the right side were not, if there was any liquid gas on them, it was not visible to me. and in case u r wondering, I removed the dry one first then the wet one, so it's not like the plugs dried out before I got there, or at least I don't think that's the case. again, this might mean nothing. but it was odd to me.
- If anyone raises the issue of engine timing (which I guess might be some what valid) I'd like to remind you the bike ran ok before the rejet and the baffle removal, but i feel other issues could be involved. how do I check for a vacuum leak??? is that a reasonable concern??? I guess this could just be a case of re-jetting going bad, VERY< VERY BAD
- I didn't expect it to be a cake walk, but this is getting ridiculous...

[Newbie_3131]

i just remember one important detail talking to somebody else: a while back, I put new spark plugs on this engine, the new ones I installed looked like the gap was a lot smaller than the ones I took out, but the bike started right away and I gave the guys at the dealer the year and model so i didn't want to bother them, Now I'm thinmking if the gap is too small, the spark will be too short (small) not enough to ignite the fuel, so the thing just floods.... warmer temps require less to ignite??? remember I now went back to a 15 pilot jet, but the main jet is a 110, what is the original gap supposed to be on this plugs????? will that gap change if we go back up on the pilot jets, or will it change merely because we changed the main jet???? i know 1 thing, the gap on these new plugs have a different gaps than the ones I took out...

[zoro]

Originally Posted by Newbie_3131

i just remember one important detail talking to somebody else: a while back, I put new spark plugs on this engine, the new ones I installed looked like the gap was a lot smaller than the ones I took out, but the bike started right away and I gave the guys at the dealer the year and model so i didn't want to bother them, Now I'm thinmking if the gap is too small, the spark will be too short (small) not enough to ignite the fuel, so the thing just floods.... warmer temps require less to ignite??? remember I now went back to a 15 pilot jet, but the main jet is a 110, what is the original gap supposed to be on this plugs????? will that gap change if we go back up on the pilot jets, or will it change merely because we changed the main jet???? i know 1 thing, the gap on these new plugs have a different gaps than the ones I took out...

Sounds like you need new plugs! Gapped to 0.7mm!

[MFolks]

Most sparkplug gaps are between 0.028" to 0.032". Replacing the sparkplug caps(most screw onto the plug wires) will help too as the resistor inside the cap can fail over time creating weak or intermittent operation.

If your ignition coils are not sealed to the plug wires,I'd suggest replacing them too. 7MM plug wires should fit and can be bought at most good car speed shops.

I may have suggested it before, but check the input voltage to the ignition coils at the primary(small wires) side. It should be the same as battery voltage. If it's down around 8-10 volts, your bike will benefit from doing a simple wiring modification using a 12 volts car relay.

It bypasses the aged,corroded wiring these older bikes seem to suffer from.Go to wiredgeorge motorcycle carburetors - Vintage Japanese Motorcycle Carburetor Sales, Rebuilding and Restoration - Home and read up on doing it.

[Newbie_3131]

I'll be brief: I re-jetted, but did not adjust the air screw (initially) I also at some point went up 1 size on the pilot jet, went extra high on the needle, so I was running too rich, so rich in fact that the spark plugs got clogged up, yesterday I spent 4 hours working on this thing and couldn't get it started, today we put a new set of plugs and she fired right up... I might be ready for a test drive and some plug reading>>>!!!

Thanks everybody

[shiftproduction]

I have a 78 KZ650 and I have had a similar problem with a Honda. I just called the local dealer and had the cheapest tire put on it and I think it was $80 for the rear tire and $35 to install, which is not unreasonable at all. Also, on my Suzuki the carbs were leaking even after I replaced the petcock, filter, and all lines so I bought a carb rebuild kit off ebay for $30 or you can get one at bikebandit.com for a good price as well and you can have some nicely running carbs after that. It fixed my fuel leak maybe it will help you. I have a nice KZ650 parts bike I need to get rid of as well and the carbs never leaked. I am currently trying to get enought posts to list it in the for sale because its in perfect condition and I dont wanna part it out **hint hint**. Hope this helps and good luck!!

[zoro]

Originally Posted by Newbie_3131

I'll be brief: I re-jetted, but did not adjust the air screw (initially) I also at some point went up 1 size on the pilot jet, went extra high on the needle, so I was running too rich, so rich in fact that the spark plugs got clogged up, yesterday I spent 4 hours working on this thing and couldn't get it started, today we put a new set of plugs and she fired right up... I might be ready for a test drive and some plug reading>>>!!!

Thanks everybody

Right on!

[kopcicle]

I'm still following along and just wanted to send a word or two of encouragement for what it's worth . Hang in there and remember I'm just an IM away if need be .

~kop

[Newbie_3131]

well tHANKS A LOT U GUYS, I definitely wouldn't have gotten this far without your help, the electrical and mechanical concepts of how stuff works are basically the same, it's only the specific steps/procedures that change. but when it comes to regulating fuel-to-air ratio, through jets and manipulating air flow (through less restricted intake, exhaust or air screws adjusted), this is all new to me, and quite frankly, more than once I've been close to seeing the power of combustion at its most magnificent work [as I light the whole bike up in flames]. But don't worry, I won't do that.! i have had some very frustrating moments. Anyway, to the bike: I went out for a short ride on friday, bike took a couple of attempts to start, but I would say nothing unreasonable considering the low temp, choke up, she warmed up and off she went, I get very poor response on acceleration, like she chokes, I brought a screwdriver w/me so I made a stop to check where the air screw was set (I had been all over the place before trying to start) it was 3 full turns out from seated position, I screwed it back down to about 1 full turn from seated position and it was better but still tough to take off from a standstill, (Note: if i rev the bike in neutral I get good acceleration, engine chokes under load, just thought I'd mention that) again, bike did not reach over 60mph, full throtle feels like she's choking, I did not have a lot of time so I had to let it go, my problem is I have a hard time telling if I am rich or lean, I could be rich at the bottom of the throttle and lean at the top, and that's the part that's driving me nuts, My 5-slot needle is set on the third slot, my pilot jet is back to a factory size 15, main jet is up from a 102.5 to a 110. baffle is out but tailpipe cap is on, reducing the actual tailpipe outlet about half in size (but no real baffle restriction), individual pod filters in each carb, now LET ME START BY ASKING THIS QUESTION: when I screw that air screw IN, does that increase the air flow into the mixture or is it the opposite??? I am going in a little while to try it back and forth, but I just want to be better informed... as far as full throttle, I figured once I can take off without stalling the plugs will tell me the rest of the story, once again thanks a lot you guys for all the help...

[Newbie_3131]

Yesterday was just the perfect day for a ride, took the bike out @ 1 turn out from seated position on the air screw, ran OK but still not right I rode around for a while then had the splendid Idea of stopping to adjust the air screw to see if I could make it run a bit better (in case you didn't get that I was being sarcastic) man did I have trouble after that!!! I had to stop like five times, and for some reason had trouble getting to run right again, sometimes the RPM would stick way up, some times it would come down slowly, some times she would just choke, give me no throttle, I tried going back to that initial setting that gave me a decent ride, but couldn't get it for some reason, finally, I got to a decent point and kept going she ran ok after that, I rode for a while, then went back to base, I later discovered was running low on fuel and at the time of trouble was going through some hills so maybe it was sucking air, and I was driving myself nuts for no real reason. Anyway, Now I think would be a good time for plug reading, I think I am too rich on the high end but I'll have to check those plugs (I'll post pics later) I did notice she idled good, and if I carefully rev'ed without going past 1/2-inch travel on the throttle she was strong, after that it felt like it hesitated for a moment, then if I kept the throttle in that same spot for a sec she caught on, (again I think its too much fuel in there) but I think we got the idle just right, she starts (although yest was a very nice day to try) One more thing, highway, full throttle, she produced about 5500 rpm, which would get me about 65-70mph I know this is because the fuel mixture is not right but I though I'd mention that

[txturbo]

You have to understand which parts of the carbs do what before adjusting things, otherwise you will be running in circles trying to get it right. The mixture at idle is controlled by the air screws. The mixture just above idle is controlled by the low speed jet.Anything above that, the mixture is controlled by the main jets and needles. So you need to focus on one area at a time. First I would adjust the air screws back to the factory setting and get the carbs so they don't flood. That needs to be corrected before you can do anything else. Once you get it so you can start it consistently and it will idle until warmed up, then you can start adjusting things. Also when reading plugs, you need to run the bike at the rpms you are trying to adjust the mixture for. For example, if you are trying to adjust the main jet and needles, which only effect the mixture from above idle to max rpm, then you need to run it at the higher rpms for a period of time then pull the clutch in, hit the kill switch and coast it to a stop and pull the plugs for a reading. If you slow it down and let it idle then you won't get a accurate plug reading for the main jets and needles.

[kawpaul]

Sounds like you are not getting enough fuel to me. Have you checked the float level with the clear hose? Bogging on throttle blip says more air than fuel usually. This is a long thread and as such I do not remember what all you checked and where you are at now. Have you checked the fuel tank cap venting?

[Newbie_3131]

I tried, and thought I had decent adjustment on those air screw, until I started adjusting them in the middle of the ride, which I've admitted, was a bad idea, but still nobody has told me which way the setting works, screw in is more air or less air??? if I screwed it all the way in until seated, would that be open all the way, or closed all the way??? (I don't want to assume anything)