Idle problem

[source]

Hi there. This is my first post on the site.

I have been riding Katanas all my life and they've always run great so I've never had to get much into the mechanical side of things. I recently sold my 95 Katana 600 and bought a 2001 Katana 600.

The bike runs great but after it warms up, when you stop at a light, stop sign, etc it slowly idles down and then stalls unless you give it gas.

I read the stickies and there are some great tutorials and walk-throughs, but before tearing my carbs apart, I'm wondering if by giving the more experienced folks a couple pieces of info, if you can point me in the right direction.

1) The person who I bought it from said the previous owner had installed a 2-stage jet kit.
2) The bike has a Yoshi RS-3 slip-on pipe.
3) The choke doesn't appear to do anything and it appears to only have about 1/2 the travel in the lever compared to my older katana. This might just be a newer design than I'm used to.
4) The seller of the bike admitted to trying to adjust the screw that is sticking out of the left side of the bike near/on the carbs himself so I'm sure I need to make some adjustments to get it where it needs to be.

My guess: The choke cable may not be attached properly or may need to be replaced, but I wouldn't think this would make it idle down once it was warmed up, so I'm thinking something needs to be adjusted or cleaned with the carbs, possibly involving the jet kit that was installed. Am I close?

Anyone more experienced have any insight for me?

Thanks in advance.

[md86]

No such thing as "stage 2 " , good guess on the choke , and I'd check/replace plugs while I was in there . Time to start tearing into it and seeing what doesn't move that SHOULD , and what DOES that should NOT .

[source]

Thanks for the response.

No such thing as "stage 2 "

I'll admit that I don't know the first thing about carbs or jet kits yet, but after searching the web, there does appear be both 1 and 2 stage jet kits. Here is an ad for dynojet jet kits referring to 2 stage jet kits and I found more info on the dynojet.com site referring to 1 stage and 2 stage kits.

http://www.mammothmotorsports.com/By_Manufacturer/Dynojet/Dynojet%60s_Jet_Kits/Page_1/322-1002__1000.html

Here was his listing describing the bike:

http://hartford.backpage.com/automotive/classifieds/ViewAd?oid=oid%3A849166

I ordered a new fairing for it that should be delivered in a few days, so I guess when I remove the fairings, I'll investigate more. Hopefully the new repair manual will be here soon too.

[Damian]

You can download the manual to tide you over until you get yours in: http://katriders.com/forums/viewtopic.php?t=13439

[md86]

Thanks for the response.

No such thing as "stage 2 "

I'll admit that I don't know the first thing about carbs or jet kits yet, but after searching the web, there does appear be both 1 and 2 stage jet kits.

Ok , lemme rephrase .... no such thing as a stage 2 for KATANA's . It'll be either 1 or 3 . I have DJ's PDF file saved on my pc , and there is NO mention of a stage 2 , nor have I ever seen such a thing before for a Katana .
And that ad doesn't tell me much other than the guy is probably dum and kant spel gud .

[source]

You can download the manual to tide you over until you get yours in: http://katriders.com/forums/viewtopic.php?t=13439

Very cool. Thanks. Mine arrived, but I brought it to work and forgot it there so can't get it until Tuesday, so thanks, this is helpful

[source]

Ok , lemme rephrase .... no such thing as a stage 2 for KATANA's . It'll be either 1 or 3 . I have DJ's PDF file saved on my pc , and there is NO mention of a stage 2 , nor have I ever seen such a thing before for a Katana .

Thanks for the response. I'll have to start taking it apart once the weather isn't conducive to riding for a few days

[source]

Update:
For the problem of the choke not appearing to work, I was right--the lever moves freely on the handlebars, but it doesn't actually move the other end of the cable by the carbs. I can move the rod by the carbs easily though, so I've ordered a new choke cable.

As for the idle problem, yesterday I changed the plugs, air filter, oil & oil filter.

It now has a lot more power, accelerates faster and more smoothly, but still has the problem where after it is warmed up, when you come to a stop it idles down and dies. I've tried adjusting the idle screw up to idle up higher, but it still idles down slowly and dies.

Can anyone suggest anything short of me taking apart the carbs? I'm decent mechanically, but still fairly new to this so trying to avoid "fixing" things that aren't broken

[md86]

If the idle drops like that and it dies , you got problems (obviously) . Sadly ,this often entails tearing things apart to find said problem . Now , the first thing I always like to do is ask the plugs what's up . If they're black (like I'm willing to bet ) , you either have weak spark , too much fuel/not enough air , or low compression . Is just 1 plug black , a pair , or all of them ?

[source]

If they're black (like I'm willing to bet ) , you either have weak spark , too much fuel/not enough air , or low compression . Is just 1 plug black , a pair , or all of them ?

All four plugs were evenly worn & black but not fouled. I agree that it is probably a fuel/air mixture issue or a vacuum issue. Being that the plugs were black, I was thinking it was running rich, but when it wants to die at a light, you have to give it gas to keep it going, which leads me to believe it is running too lean and getting too much air. If I had an air leak, I've been told you can spray WD40 at the suspected leak locations which will cause the engine to reve up briefly. If this is the case, where can I check for vacuum leaks?

I cracked open my Haynes manual tonight and its great. I've learned quite a bit so far but am still a novice.

I fear I'm going to have to next explore the pilot screws under the carbs or maybe go on a wild goose chase for vacuum leaks, which is hard when it won't idle when warmed up...


P.S. When I asked the guy at the parts counter at a local dealership if there was an inline fuel filter on my bike, he said no, but I see an inline module in the gas line that clearly looks like one. I'm thinking that probably isn't the issue, but if it is one, it probably wouldn't hurt to replace it I guess.

[source]

If it's running great when driving, but slowly dying at idle, could it have something to do with the custom jet kit that was put in before I bought it? If so, does anyone know specifically what could be wrong or what to check?

[moto_psycho]

the idle is probably due to only the main jets being fiddled and not the idle jets, mine is like that, but to me it aint worth the hassle

[md86]

Um ............
You guys are both WAY off , but partially right at the same time . See , if it don't wanna idle , the mix is off . If the plugs are getting balck, it most LIKELY getting too much fuel . And the idle is the HARDEST part to get right . Mine runs ok , but won't idle at ALL . If the plugs are getting black , it may stil runn , but it AIN"T gonna wanna idle . So ....... you got some work to do , eh ? But since I'm at the rally and geting fairly ...... um ..... drunk right now , I'll get back to you ....

[TRH1]

I had the same problem with my bike a 1995 Suzuki gsx600f 26000miles, the reasons it does this is because the mixture is too rich, due to either the float being too high. The other reason is the emulsion tubes wear easily because they are made of brass and the needles which slide up and down in them are made of steel.The wear more if you do alot of town riding as they are going up and down alot! They start out round and become oval, hence letting in too much fuel at idle and just off idle. You can either replace all your emulsion tubes. Or what I did was lower my float levels by 1mm ,so increased float height, as you measure from carb body to top of float when upside down. This will weaken the mixture slightly.
It worked for me, best of luck!

[md86]

Yes , what HE said . Way to pick up the slack .