Strange Fueling after Carb Clean

[ncarota]

Hi Guys,

First, thanks of for the wealth of information I've found on the site already! It's been a great reference. I just purchased my GF a '05 Ninja 250 as here first learner bike. It was in good shape, only 11k miles on her, but the throttle hesitated on acceleration. I changed the oil and filter, the problem still persisted. After some googling I decided that I should probably start with the carbs. The bike had been sitting for a year and a half before I brought it, so I decided If I was going in for a clean, I might as well rebuild them while I'm in there.

I've never cleaned carbs before, but did some cursory research and it seemed doable. Removing them was a bit of a pain but once they were out things went smoothly. There was some gunk in there, and a bit of particulate at the bottom of the bowls. I removed the brass fittings, sprayed everyghing thoroughly with carb cleaner, let it soak, then sprayed again. I replaced the parts that came with the rebuild kit and returned the other brass fittings on the carb to their original places. I also set the idle mixture screws to where i found them(3 full turns).

She started just fine chocked, but was way slower to warm up(I had the keep the choke on for 5+ min), but would still stall after chugging around 800rpm I adjusted the idle knob thinking that was the problem. It did help, but then she would stick at high revs after throttling her up. I returned the idle knob back to a lower position where the revs wouldn't stick, then adjusted the idle fuel mixture screw out(now at 4 turns). This seemed to rectify the problem with idle being too low, but doesn't seem normal either. When I rev her up now(which she does happily and quickly now), the idle she returns to is very low(800rpm), and she sometimes stalls. If she doesn't stall, 20 seconds later she start idling more smoothly. It's more pronounced when she's just been warmed up, but still occurs if she's been running for awhile.

Any ideas? My buddy suggested we check the valves, but I can't see that being the cause of the problem since it occurred only after the carb clean. I'm not sure what relationship the idle screw has to the idle fuel mixture screws, except through trail and error. Am I approaching this the wrong way?

Thanks for your time and patience.

Nick

[Ghostt]

Idle should be set around 1,200 return the idle mixture screws to 3 turns out, then tune them,

Warm it up, turn 1 side pilot screw in until the rpms drop, then back out till RPM's peak (and no further)* Twist throttle...see how it reacts...tweak to taste.
Repeat on other side... test ride. You're looking for best throttle response and transition from just cracked to 1/4 throttle opening or so.*

Thats a quickie, 10 cent tutorial on setting pilot screws.**

Also are you using the OEM airbox?

After that check for proper Petcock functional, check spark plugs, and clean the spark plug caps, and redo the plug wire ends, and then do the valve adjustment, as it probably has never been done.

[ncarota]

Thanks for the info, that's exactly what I was looking for.

Yes, stock air box, but I had to replace the filter, the other one was falling apart. We've checked the petcock, but will definately check the plugs when we are getting to the valve cover.

Cheers,
Nick

[Ghostt]

Also check the carburetor boots, they are a pain to get back on correctly. Also double check to make sure the carburetors are assembled correctly, and check the float settings.

Also check for vacuum leaks, and the petcock is working properly, and not leaking on the vacuum side either.

You need to verify the petcock is petcocking, err, i mean working properly.*

PETCOCK TEST
install a fuel hose from the petcock fuel outlet into a catch can. Pull the vacuum hose from the engine side. Leave it connected to the petcock.*

Now...petcock set to on.... fuel should NOT be flowing. Apply suction to the vacuum hose (which is connected to the petcock ONLY) ...fuel should now flow.*

Make sure the vacuum line doesn't have any pinholes or cracks!

[flitecontrol]

In my experience, spray carb cleaner will not thoroughly clean a very dirty carb. The fact that you have to keep fiddling with various carb circuits would support the conclusion that the carb isn't completely clean.

If you have access to a sonic cleaner, they clean carbs thoroughly and quickly. If not, buy a gallon of Berrymans Chem Dip, usually around $16 at WalMart, and soak only the metal parts in it for at least 48 hours. Do jot soak any rubber or plastic parts in it as it will destroy them.

After soaking, thoroughly rinse with water and use an air compressor to blow out every opening in the carb before reassembling.

[ncarota]

Gotcha, we will double check the petcock.

Just finished the checking the valves; they needed adjustment. Old sparks looked good, replaced them anyways. I'm gonna pull the carbs apart again reinspect. Local motorcycle shop has a subsonic cleaner, so I'll see how much it is.

Thanks again, great advice.

[flitecontrol]

About the cheapest shop charge I've found is around $45 per carb, plus any needed parts. That's one reason I invested in a used sonic cleaner, and it's paid for itself many times over.

[ninjunk]

i wasn't super impressed with the ultrasonic i had, but it was old and pretty well shot.

i have been using denatured alcohol in a 1 gallon 'dunk' bucket. way less noxious than the 'carb dip' type stuff, and it is seems to do a better job.

still, at the end of the day, no dunks, ultrasonics, boiling or anything will clear out those really tiny passages. you absolutely have to blow out each one with a straw on the carb cleaner, then wire it, then blow it out again (checking for a good flow pattern through the outlet) and if you can, blow it out finally with compressed air.

The ones i think cause the idle fluctuations are the tiny holes on the emulsion tube. On my carbs, even after a pretty thorough blowing out, i had to poke about half of them through with a wire and some were pretty stubborn.

Also wipe down the needle as sometime film builds up on that and causes issues.

[flitecontrol]

Originally Posted by ninjunk

i wasn't super impressed with the ultrasonic i had, but it was old and pretty well shot.

You can test whether or not an ultrasonic cleaner is working by placing a strip of aluminum foil in it. After a few minutes, the foil should have a lot of small holes in it.

i have been using denatured alcohol in a 1 gallon 'dunk' bucket. way less noxious than the 'carb dip' type stuff, and it is seems to do a better job.

I can only surmise that you never used Berrymans Chem Dip, or didn't leave the carb parts in it long enough. I know of nothing that is as aggressive as Chem Dip that will not damage the carb.

still, at the end of the day, no dunks, ultrasonics, boiling or anything will clear out those really tiny passages. you absolutely have to blow out each one with a straw on the carb cleaner, then wire it, then blow it out again (checking for a good flow pattern through the outlet) and if you can, blow it out finally with compressed air.

Sorry, I have to call pure BS on the above statement. How do you think mechanics get carbs clean, and why would they spend hundreds or thousands of dollars for ultrasonic cleaners if they didn't thoroughly clean carbs? There are youtube videos graphicly showing what happens to filthy carbs when placed in the cleaner.

The ones i think cause the idle fluctuations are the tiny holes on the emulsion tube. On my carbs, even after a pretty thorough blowing out, i had to poke about half of them through with a wire and some were pretty stubborn.

Also wipe down the needle as sometime film builds up on that and causes issues.

I disagree with the neeed to use spray carb cleaner at any time, unless you are using a carb cleaning solution that just isn't strong enough to get the job done. In that case, use the right product for the job at hand, and it isn't spray carb cleaner. There may be solutions that clean carbs better than Chem Dip, which is specifically made to clean carbs, but I'm not aware of any.

Regarding the need to use spray cleaner after using Chem Dip, that hasn't been my experience. On the contrary, I've cleaned a bunch of carbs that the owners tried cleaning with carb spray. After going through the Chem Dip, rinsing, and blowing out with high pressure compressed air, they all worked flawlessly. There was no need to poke wires through any orifices as the Chem Dip removes all the gunk! It doesn't tqake much poking with a steel wire to enlarge the holes in jets, and it simply isn't needed if the right cleaning solution is used.

More jets have been ruined by novices using wires or torch tip files than anything else. Jets should last as long as the bike does. But if you buy a used bike, you may have inherited the PO's misguided attempts at cleaning which enlarged the jet orifices.

[jkv45]

I agree with flite - if you are using the right carb dip you shouldn't have to go into the passages with carb cleaner and a wire when you are done.

I have some old school carb cleaner that I submerge the completely stripped carb in for a hour or 2, then rinse, then into the ultrasonic bath for a couple of cycles (changing the position of the carb), then rinse with D.I. water, then submerge in a liquid chemical conversion "Nano" coating, then blow out all passages with high pressure air. The Nano coating process prevents corrosion.

That will usually do it.

I think there are times where replacing the brass parts (jets/holders/emulsion tubes) with new isn't a bad idea - like when you think there may be internal corrosion. It doesn't take much to alter the flow of a jet.

[ninjunk]

Ha yeah the ultrasonic i had wouldn't even come close to putting holes in aluminum foil. What brand are you guys buying? I've used some pretty high dollar ones over the years (at a research lab i worked at, and in jewlery class) and never been super impressed with them. What solution are you using? When i had mine i tried a couple different degreasers, even CLR, nothing worked all that well. It was awesome for cleaning transmission gears, but never seemed to break up varnish.

I had a jug of berryman's carb dip and never liked it. The denatured alcohol costs about 7 for the jug and 2 for the metal pail. Berryman's was 20+ dollars last time i looked at the price at the auto parts store. Plus I keep a second glass pickle jar full of it for cleaning jets, screws, and tiny stuff that would be too hard to fish out of the big can. Most of the time i leave carbs in it for a week or two while i work on other systems in the bike, and finish up with the fuel system once everything else is sorted out.

I've cleaned hundreds of carbs over the years both restoring bikes and as a pro mechanic, and i've tried most of the things people suggest. Nothing i've ever found has removed set up varnish and gunk as well as a good old fashioned toothbrush and piece of copper wire. Even if the holes are clean you won't know that they are clean until you poke them and spray them so you can watch the spray pattern. I don't know of a better way to do that than with the straw on a can of chemtooler.


I'll post some before and after pics of my ninja float bowls, they have been soaking for about a week, definitely some of the more stubbornly jelled carbs i've worked on in the last couple months.


If you've got a ultrasonic setup that works good for you and isn't crazy expensive, i'm all ears, i've been wanting to get another one even if i don't use it for carbs, they are really good at getting carbon build up from pistons, ring grooves, etc.

[dcj13]

Welcome, Nick! Good to have you here. Lots of good information!

All good advice in this thread.

I would have started by running a tank of fresh gas with Seafoam or Gumout or the like, however.

Where the heck is Comox?

[Ghostt]

I usually do not recommend CHEM-DIP for the novice person, for a few reasons, first as indicated it's hard on rubber, and plastic, namely the O-Rings, and fuel inlet, rails, etc... And the carburetors need to be split, to allow a thorough cleaning, and replacement of O-Rings etc....

For the novice, and average person I recommend sonic cleaning, purchasing new pilot, main jets, along with main holders/emulsion tubes, and rebuilding kit, for the reasons that they are sometimes difficult to clean properly, and maybe damaged from previous attempts of cleaning, there fairly cheap for piece of mind. Then blowing out all circuits with an air compressor.

Worst case buy several cans of carburetor cleaner, and canned air, replace the parts as I mentioned above, along with what comes in a rebuilding kit.

[Ghostt]

Here's a link to find some items you will need,

http://www.partsnmore.com/parts/kawasaki/

[flitecontrol]

Knowing little about sonic cleaners, I bought a used American made sonic cleaner on ebay. I'm guessing it may have been used to clean dental tools. It cost around $80. Avoid the Chinese made jewelry type cleaners as they probably won't last as long. Having a cleaner large enough to hold the entire carb is convenient.

I've heard several folks say that the current Chem Dip formulation isn't as strong as it used to be.

[ninjunk]

^yeah i figured that was the implication when JKV45 said 'old school' carb cleaner. I dunno when they changed it, but as long as i've been alive and working on stuff, its not worked well for me.


Do you have a brand name on that cleaner? What kind of solution/chemical do you use in it?

I think the one i had was like 'Branson' or something like that? It was pretty old, 80's vintage maybe.

I'll check ebay, i forget that you can get pretty good deals on industrial equipment on there.

[ninjunk]

far out, found it

this is the exact one i had, wasn't worth a damn
http://www.ebay.com/itm/See-Video-Co...item2c94dcf7f6

[ninjunk]

oh yeah, one more thing... not trying to beat a dead horse here, but check out the denatured alcohol.

i had never really used it until i worked in a machine shop where we used it to get nice clean cuts on aluminum.

started using it for everything from cleaning machines, prepping surfaces for paint, etc. it is like the ultimate solvent. I've convinced a few people to start using it as carb dip and you'd be surprised the stuff it works for. I use it to clean engine parts before installing them (final wipe down) and lots of other stuff around the shop. It will even remove graffitti and low quality paint without wrecking high quality paint underneath (much) although acetone seems to be better for that sort of thing.

buy some and try it out, you might be surprised, its like brake cleaner without the fumes and much much cheaper.

it also absorbs and displaces water so you can use it the same way you would use HEET or something like that.

pretty much everything i clean in my shop gets done with either a bucket of kerosene for heavy grease, or denatured alcohol for light grease/varnish/final assembly/painting.


if you run into anything that is insanely stubborn with varnish, MEK is the most brutal thing you can buy. It will flat out melt plastic, any styrene plastics will be turned into goo. I use it to get deep seated varnish (like 1/2 thick solid varnish) out of the bottom of gas tanks before acid cleaning them. Its also turbo-carcinogenic, absorbed through the skin, but damn does that stuff work good.

I would guess that berryman's is a mix of acetone, toluene, and MEK just by the way it smells.. they may have gone to a less-carcinogenic MEK-substitute recently hence why it doesn't work so good. Most of the engine cleaner/fuel system cleaner/etc stuff is just a cocktail of solvent and you pay 3-4X as much for a fancy label and bottle.

[ncarota]

Here's an Update;

Testing the petcock revealed that the brass tube connecting the vacuum hose was loose on the tank side. That and the valve adjustment made it run alot better, but still the drop in idle after revving. Removed and cleaned the carbs again(ultrasonic at shop). Also checked float bowl height, which was in spec(17.8mm).

The only spark plugs I could get locally were the CR7HSA not the CR8HSA. So there a tiny bit longer. The guys assured me it would not be a problem, but I'm curious for opinions. Haven't started her up yet since the carb clean, so I'll let you know how that goes.

Thanks again for all the input.

Cheers,
Nick

[jkv45]

Originally Posted by ncarota

Here's an Update;

Testing the petcock revealed that the brass tube connecting the vacuum hose was loose on the tank side. That and the valve adjustment made it run alot better, but still the drop in idle after revving. Removed and cleaned the carbs again(ultrasonic at shop). Also checked float bowl height, which was in spec(17.8mm).

The only spark plugs I could get locally were the CR7HSA not the CR8HSA. So there a tiny bit longer. The guys assured me it would not be a problem, but I'm curious for opinions. Haven't started her up yet since the carb clean, so I'll let you know how that goes.

Thanks again for all the input.

Cheers,
Nick

That plug is one heat range hotter. Depending on your riding it may or may not be a problem - but I don't know how the guy can assure you that it won't.

Only time I can see a hotter plug being a good idea is for the hypermilers who spend all of their time just chugging around at low revs. Sustained high revs are a problem with a plug that's too hot.

[Ghostt]

Agreed it maybe a problem or not.

Also don't forget to disassemble and clean the spark plug cap, and redo the connections on the ignition wires

[flitecontrol]

Originally Posted by ninjunk

^yeah i figured that was the implication when JKV45 said 'old school' carb cleaner. I dunno when they changed it, but as long as i've been alive and working on stuff, its not worked well for me.


Do you have a brand name on that cleaner? What kind of solution/chemical do you use in it?

I think the one i had was like 'Branson' or something like that? It was pretty old, 80's vintage maybe.

I'll check ebay, i forget that you can get pretty good deals on industrial equipment on there.

My sonic cleaner is an Adfa, model T1.9C. Not sure they are even made any more. But you can do an online search for U.S. made sonic cleaners and find quite a few. Look for positive reviews before buying. A cleaner with an internal removable basket is a plus.

I use Chem Dip in the cleaner, but don't use the cleaner's heating element as the sonification process alone generates heat. The following is a write up I did for another forum:

Disclaimer: Chem Dip is flammable. I have used it with good results in my sonic cleaner, but I monitor it closely. Anyone trying this should do so as well and have the cleaner in a location where it cannot cause damage to homes, vehicles, etc. if the Chem Dip ignites. Have a fire extinguisher rated for flammable liquids handy, and know how to use it. Use an extension cord to locate the cleaner away from flammable materials. Chem Dip is available at Wal Mart and most auto parts stores.

Run only the metal parts of the carb through the cleaner with Berrymans Chem Dip as a solvent. The plastic float, rubber tipped float valve, gaskets and O-rings should not be placed in Chem Dip. There are O-rings on the air/fuel and carb drain screws, so remove them before placing in the Chem Dip.

Do not use the heater if the cleaner has one, as the cleaner will make significant heat on it's own. Monitor it closely, and when vapor begins to come off the surface of the liquid, turn it off. In warm weather, this takes about 45 minutes to an hour with my cleaner.

Then rinse the carb parts thoroughly with water and blow out every orifice with high pressure compressed air.