I've always had a rich/lean spot around 5500. blah blah blah rejetted, blah blah blah, runs worse now blah blah blah... but here's the run down:
K&N lunchbox + full V&H + 134 Main & 40 Pilot (what WAS in there) = ok, but flat spot at 5500 or so. WOT + a heavy engine load (uphill, highspeed, heavy acceleration) meant it would cough and stutter usually while SNAPPING the throttle open.
fast forward...
K&N lunchbox + full V&H + 150 main & 40 pilot + 1 #4 SS washer (what's in now) = it seems like ANY WOT snap means bogging or frappapapapa **cough** **cough** frppapapapa like it's riching out. Now, given, my mixture screw is frozen on ONE carb, and I'll be tackling that today.
If I SNAP open the throttle, from a lower rpm like 3,000-5,000, it will cough and bog while TRYING to acccelerate. Regular drivability is ok in lower rpms. If I ROLL the throttle it will accelerate kinda ok, but not as smoothly as it should.
here's the question part:
Does this mean the Main is too big, (the matrix says it's perfect, lean at idle) or that something else is screwing with it ? I mean, besides the frozen mixture screw right now.
Check your slides to see if the ports in the bottom of the slide are plugged.
I had a very large dead spot between 4,000 and 5,000. Turned out the previous owner plugged both of those ports with nylon screws. I was able to salvage the situation by drilling out one of the nylon screws to expose the original calibrated orifice beneath. Runs like a champ now.
K&N lunchbox, full V&H, 150 main, 40 pilot, 1 washer on stock needles, 2 or so turns on the idle screws.
Quote from: GeeP on February 10, 2008, 08:42:47 AM
Check your slides to see if the ports in the bottom of the slide are plugged.
I had a very large dead spot between 4,000 and 5,000. Turned out the previous owner plugged both of those ports with nylon screws. I was able to salvage the situation by drilling out one of the nylon screws to expose the original calibrated orifice beneath. Runs like a champ now.
K&N lunchbox, full V&H, 150 main, 40 pilot, 1 washer on stock needles, 2 or so turns on the idle screws.
Oh wow, I wondered about those. One of the screws has a hole, the other does not, on each slide. One more thing to try today.
The need should be (starting from the bottom) small doughnut in the slide, #4 washer, clip, big doughnut, right ?
Man, I"m really beginning to wonder about things. :)
You have the wahser on there right, but I suspect you are rich at 5000-6000RPM since it got worse by going to a larger jet. You actually need to lower you needle, which I don't think is possible on stock needles.
The stuck idle mixture screw won't really have an effect above idle so don't worry about that(you still should take care of it obviously)
Quote from: ohgood on February 10, 2008, 09:41:17 AM
The need should be (starting from the bottom) small doughnut in the slide, #4 washer, clip, big doughnut, right ?
Man, I"m really beginning to wonder about things. :)
The flat sided donut goes on the needle, then the washer, then the clip, then the stepped spacer (spring seat)
ya, that's how it was. here are the combinations i've tried:
150/40 2nd clip from the end + 1 #4
150/40 2nd clip from the end + 2 #4
150/40 1st clip from the end +1 #4
150/40 1st clip from the end +2 #4
after all that, i gave up on the 'perfect' from the matrix and went back to what was ridable:
134/40 2nd clip no washers
134/40 1st clip no washers
thats 7 freaking times to take the tank off in a day.
then I checked the floats again, drained the bowls just to make sure fuel was clear and flowing well.
fiddled with the one working mixture screw.
got a fresh 3 gallons of gas, drained the tank, tried with fresh gas.
drained the fresh through the bowl drains.
gave up, decided to sell. so freaking tired of just putting up with shaZam! carburetors that are NEVER working right. as soon as someone volunteers to look at my carbs for cash, i can sell it and be done with the mess.
too bad a EFI system was never produced for the gs. this is the one nagging point since I bought it I just can't stand anymore.
OK, you're like a jigsaw puzzle. 134 - you got DJ jets ... only way a 134 will be rideable.
If you got that, stay with 134 ... 150 will not work.
But, WOT snap = bad, WOT gradual = good => that the slide is comming up too fast.
Cool.
Srinath.
Quote from: GeeP on February 10, 2008, 08:42:47 AM
Check your slides to see if the ports in the bottom of the slide are plugged.
I had a very large dead spot between 4,000 and 5,000. Turned out the previous owner plugged both of those ports with nylon screws. I was able to salvage the situation by drilling out one of the nylon screws to expose the original calibrated orifice beneath. Runs like a champ now.
K&N lunchbox, full V&H, 150 main, 40 pilot, 1 washer on stock needles, 2 or so turns on the idle screws.
I had the same thing, drilled one out and the bike ran great.
Ohgood, how many grooves are on your needles? If you have more than one groove, they're not the stock needles. If they only have one groove, check your Clymer's manual to see if the number on the needle matches the stock needle in the book.
Needles of the wrong taper will cause a tuning problem. I had dynojet needles in mine originally. It would not run 150 mains with the dynojet needles. (They have 5 possible positions for the e-clip)
Ohgood, I can almost be certain I can solve your problem, probably yours and seamax's problem in 1 sweep.
I'll find and buy katana carbs. 4 carbs = 4 needles = 2 each for the 2 of you ... here is the kicker ... I am yet to make a junkayard run since mid Dec, so no clue if they have a set. But evidently I have 3 junkyards that may, so ... hope for the best.
Cool.
Srinath.
So you have 2 things going against you right now, first you have a Dyno Jet kit installed on the bike. The second is that you live somewhere warm where you can ride year round. Okay maybe the second thing is me just being jealous.
My question is do the 134 jet and 150 jet look the same in terms of overall shape? I suspect that the 134 is the Stage 3 dynojet jet. My guess is they installed the nylon restricters, so if one can be removed that may help the acceleration issues. So the other is tat you have DJ needles which means there is no need for #4 washers. With stock needles you need to shim the needle with #4 washers, but since you have DJ you can simply move the clip up and down. So basically you never tested the top needle position because you did "top needle position + 1 washer" which is really the second needle position.
Anyway, if the 134 jet has a smaller outside diameter than the 150 jet, odds are that it is a DJ jet. The DJ number for a jet is not the same as a mikuni(i.e. a 134DJ is about the same as a 150 mikuni). I would recommend trying the 134 Jet, and the 1st needle position and see how that runs.
Also you need to take a look at the plugs to see if you are rich or not. A plug chop method is the best if you have some open roads by you.
Quote from: coll0412 on February 10, 2008, 08:38:33 PMSo the other is tat you have DJ needles which means there is no need for #4 washers. With stock needles you need to shim the needle with #4 washers, but since you have DJ you can simply move the clip up and down. So basically you never tested the top needle position because you did "top needle position + 1 washer" which is really the second needle position.
Coll, the dynojet needle is a completely different taper than the stock needle. I don't recall what the actual taper is anymore, but it is drastically different from stock.
OK, I hadn't realized this was a DynoJet mess. :(
So, it looks like I have a dynojet needle, according to srinath a dynojet 134 main, and 1 1/2 plugs in each slide. Yuck.
Ya, the weather here = year round riding. It's nice, but right now I'm so frustrated with carb crap I really don't care. Be jealous if you like, but know I'm not getting to enjoy it with constant carb crap keeping it parked.
Yea 134 and DJ crap, and dont believe 1 1/2 plugs is hurting you, the slide is still rising too fast.
The needles of course make the slide rise that much more sensitive. A stock needle is actually very forgiving in most bikes with stock slide - it may come up a bit too quick, but it will deal with it just fine.
Cool.
Srinath.
Quote from: GeeP on February 10, 2008, 11:58:54 PM
Quote from: coll0412 on February 10, 2008, 08:38:33 PMSo the other is tat you have DJ needles which means there is no need for #4 washers. With stock needles you need to shim the needle with #4 washers, but since you have DJ you can simply move the clip up and down. So basically you never tested the top needle position because you did "top needle position + 1 washer" which is really the second needle position.
Coll, the dynojet needle is a completely different taper than the stock needle. I don't recall what the actual taper is anymore, but it is drastically different from stock.
Yeah I am aware of that, I have a set of the DJ needles in my bike. They are a pain in the ass to get to work, but dropping the needle further into the jet will lean it out at part throttle conditions. Stock needles are much easier to work with though, that is for sure.
Not really a carb problem, sounds like your bike is lacking a RWD.
RWD = right wrist damper :laugh:
Yeah I am aware of that, I have a set of the DJ needles in my bike. They are a pain in the ass to get to work, but dropping the needle further into the jet will lean it out at part throttle conditions. Stock needles are much easier to work with though, that is for sure.
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I suppose I could always try leaning it (raising the clip) but at this point the original (to me) setup doesn't even yield ridable results. The carbs are clean, spotless (inside) actually, the slides slide freely, the needles and jets are seated proper, the only thing I can't be certain of is the one stuck mixture screw that is seized. Since it's back to what it has been for over 10,000 miles, and runs exactly the same (crappy) as the first time I did rejet, I'm at a loss.
Quote from: gsJack on February 11, 2008, 10:26:50 AM
Not really a carb problem, sounds like your bike is lacking a RWD.
Well, if putting a rubber worm in line with the cable would do it, I'd buy a stock pile ;)
I"ve put out PM's for needles/slides. shrug.
The thing is, you can train yourself to open the throttle slower, I did that with my one and only bike that needed that.
The DJ needles can be finnicky, stock needles are near impossible to get wrong ... remember DJ started out as a kit that you only drop in needles into the stock carbs ... From there it went to this. Gradual tapers are far more forgiving, you have larger mains and they meter out almost linearly.
Oh yea, you heard some Idiot talk about his DJ titanium needles that are so great and so much lighter and more power than stock ... yea, he save a whole ... 1/2 gram.
Cool.
Srinath.
Yeah dyno time is the only real way to ensure its good. The other option is that you main jet is just too big. Have you got past the dead spot, full throttle for 20 seconds, hit the kill siwtch, coast to the side of a non-busy road and pulled the plugs. If you are rich then going down on the main jet may help with the 5000 RPM lag.
Also have you checked the float levels?
I would recommend that you try first raising the clip one spot, check your float levels with the u-tube method, and if nothing works call up DJ and order a 132-130-128 jets and kepp trying. Its a pain in the ass, but its $100 an hour for a dyno tune. It may be worth your time if you can not get it right, the bike will work like a charm for sure then.
Quote from: coll0412 on February 11, 2008, 05:53:51 PM
Yeah dyno time is the only real way to ensure its good. The other option is that you main jet is just too big. Have you got past the dead spot, full throttle for 20 seconds, hit the kill siwtch, coast to the side of a non-busy road and pulled the plugs. If you are rich then going down on the main jet may help with the 5000 RPM lag.
Also have you checked the float levels?
I would recommend that you try first raising the clip one spot, check your float levels with the u-tube method, and if nothing works call up DJ and order a 132-130-128 jets and kepp trying. Its a pain in the ass, but its $100 an hour for a dyno tune. It may be worth your time if you can not get it right, the bike will work like a charm for sure then.
Now that I've blown off some steam...
I'll do like you suggested, set the needle to the top clip position, recheck the float height, drop the 134 main in, and blast out all the orifices again. I hadn't realized this was a dynojet mashup. I did visit their website to try and see what the 'kit' consisted of, I can only assume it's the needle, a main, and possibly a slide ? Had I known that I'd just ebayed for a new stock set of carbs and made one GOOD set to ride.
Oh well, the list gets longer. Maybe that guy that put a megasquirt and turbo on his will offer a bolt-on EFI kit.... (dreamin)
Hey dude, I feel your pain. I fought with my 89 for weeks just trying like hell to get out of the dead spot I had between 5500 and 6500. I WAS running a 150 main (Mikuni), 37.5 Pilot (Ass clown that sold me the bike claimed he did a stage 1 jet kit...Ass Clown!), and DJ needle on #1 Clip. After getting the feeling I was running too damn rich, I dropped the money on 40 pilots and 140 mains (all Mikuni). Followed the instructions for the Stage 3 DJ Kit with some tweeking of the Matrix and she's finally rideable. I'm still not 100% satisfied, but after all that headache, if I can keep up with my buddies 900 Duc, I think my GS is inline. Keep fighting with it dude. Take some time away, come back with a new perspective and get it back out on the street!
Cheers!
So how did all of this turn out Ohgood? I know this thread's been dead a while, but I've got the same problem with WOT snap and DJ needle. Did you take the DJ needle out and put in stock needles? Change up the slides at all? Please tell. Thanks
WOT snap = bad, gradual open = good means the slides are rising too fast.
However you drop in the stock needles, you have to get mikuni mains for it. The funky ass DJ crap mains will not run right.
The stock needles gradual taper can alleviate that snap throttle problem.
You can still block 1 hole on the bottom of the slide and see if it helps, but tapping and closing up your slide holes is defintely scary.
Cool.
Buddha.
If I switch to the stock needles, what can I expect from it? Will it be a smoother power band? I don't remember for sure, but last time I was in my carbs, I think I remember seeing only one of the two holes open on each. I don't know if the previous owner had already plugged one of them. I'll have to open them up and fine out. If this is the case, can I drill it out if need be, if/when I get the stock needles? (if needed)
You have 1 hole plugged and you're still acting like its rising too fast ... yea you're screwed, you need to plug 1/2 the other one, or switch to stock ... and you ahve to do mikuni mains as well with stock needles ... Or train yourself to open throttle slowly.
Cool.
Buddha.
I have learned to open it slower, but I'd just like it to be dialed in completely. Thanks for the info. I'll have to see what I can figure out this weekend.