I tried to search for it but I'm having trouble finding what I need. So I'll ask the experts.
The whole time I lived in Indiana, my bike ran like a champ. I moved to Hawaii last summer and it runs fine but won't idle to save its life. I don't know a whole lot about carbs other than a basic idea of how they work. I can tell you I adjusted the idle up a little and it helps some, but every time I go for a ride I have to leave the choke cracked a little to keep the RPM's up and it's fine. I'm idling about 1K after the last adjustment but now I'm getting a little popping just off of idle. That usually indicated a lean mixture, right ? Also if I blip it a little bit, it holds just over 1K and then drops and dies. I'm around 22K miles and have never touched the carbs. They were balanced at the 18K service a couple of years ago. First thing I plan to do when I get a chance is pull the plugs and see how they look. I know how to read plug color. I've only turned the idle adjustment screw a total of 1 1/2 turns a quarter turn at a time. I also looked up elevation where I was and it's only 60' above sea level and I'm maybe 100' above now so I'm not so sure that's it other than air quality being MUCH better here. Please help.
Are you sure you're turning the idle adjustment and not the synch screw?
It doesn't make a lot of sense, to me anyway, why your location would cause this.
A hanging idle is usually a sign of an air intake leak.
Yeah, like Ducpainter said, you could be turning your sync screw on accident, it's really near the idle speed screw. If you need to sync your carbs up as a result of accidentally turning that and not the idle speed screw, it's very simple to build a DIY manometer and sync them up.
Thanks for the ideas fellas. From what I remember seeing when I had it apart a few years ago, the sync screw is up in there a little bit. The idle screw is way easier to get to from under the airbox with a regular screwdriver. I'll get my spotlight out and look up under there again to make sure I have the right one. If the sync was indeed turned by mistake, I know where to tap the intakes. I still have the hose connections. But, what vacuum range does it normally operate under? Like 10-12" mercury vac ? I worked in a distillation plant for 15 years so this makes sense to me.
Quote from: GRUBBY on April 22, 2013, 04:19:26 PM
Thanks for the ideas fellas. From what I remember seeing when I had it apart a few years ago, the sync screw is up in there a little bit. The idle screw is way easier to get to from under the airbox with a regular screwdriver. I'll get my spotlight out and look up under there again to make sure I have the right one. If the sync was indeed turned by mistake, I know where to tap the intakes. I still have the hose connections. But, what vacuum range does it normally operate under? Like 10-12" mercury vac ? I worked in a distillation plant for 15 years so this makes sense to me.
You aren't looking for a number. You are looking for equal vacuum. At least to me, the synch screw is easier to reach.
Try looking here for screw locations:
http://www.ducatisuite.com/carbsynch.html (http://www.ducatisuite.com/carbsynch.html)
I prefer mercury sticks or something like a TwinMax to a vacuum gauge. Either you need two matche gauges or you need to go back and forth from cylinder to cylinder
One of the screws is black and the other is plated.
I wish I could remember which was which.
IIRC when I had it apart, the sync screw is in between? The slot in the bottom of the airbox that a screwdriver runs along to the zinc played screw is for idle I hope because that's the one I turned.
Once we move into our house I can get my manual out. It's just irritating me right now because it's not right and I can't find a logical reason for it. It being right other than it sitting for 5 or 6 weeks. No different than Indiana winters to me though.
The cam the throttle cables are connected to has a little arm(sort of) sticking off of it. The screw I turned touches that arm from what I can see. That should be the idle adjustment. I should just pull the pin and get some FCR's and be done with it already.
Linked from Ducatisuite:
(http://www.ducatisuite.com/carbadjust2.jpg)
Yep, that's the one. I never thought of it until now. The more I turn the screw the more it pops. I wonder if it's not leaning out but if its loading up. Is it possible I'm going the wrong way adds need to back the screw out? Looking last night, there's not much left in that spring before its compressed for the screw.
That screw only controls idle speed...not mixture.
Here's why I asked that. When I got the bike it already had a K&N filter on it. I don't know if it was jetted. Before I went +2 on the rear sprocket, it was acting like it was trying to flood at 55-60. That's normal highway speed. Twice it did flood. It totally fell on its face and reeked of gas in the exhaust. From what little I know about a carburetor, when it does that you hold it WOT and crank it a little at a time. I had a IH Scout that did it to me all the time. I did that on the side of the road with my bike both times and it fixed it. Added the +2 rear sprocket and it shifted the RPM's up enough it stopped. Or so it seems. The 4 or 5 track days I did the damn thing ran reallly good. But the rubber band in the motor was getting stretched pretty tight. Fast forward to now. If the RPM's are 2000ish or up everything is normal. Idle is just shit. That's what's confusing me.
How many miles on the bike?
I said 22k before but it's just under 21K.
Quote from: GRUBBY on April 23, 2013, 08:50:04 PM
I said 22k before but it's just under 21K.
If you've never replaced needle jets...
it's time.
That's an answer I can live with. Thanks DP. I got it at 10K miles several years ago. Now I'll have to add something else to the list of molested parts. That leaves the seat and motor innards untouched. If I could only talk the wife into letting me pull the pin on FCR's. I hear they're way more simple.
Ok. So I replaced my needle jets finally. Now I have the problem of a 4K rpm idle and it appears to be the front cylinder running a little leaner. I did not set the float height to 14mm as prescribed on this board. I haven't unpacked all of my tools yet. I took everything apart replaced the tubes and put it back together. This sounds like a vacuum leak to me. Should I look at the rubber above or below the carbs first?
A vacuum leak would cause similar symptoms, but I have a hunch that isn't it. For one, if the leak was in the vacuum lines, why would changing the needle jets cause it? A leak between the carbs and intake runner could have been caused by removing and installing the carbs, but that wouldn't be my first guess.
My guess is that the 4K rpm problem is probably the idle speed set just a little too high, which can be solved by simply turning the idle adjustment back, and that the front cylinder running a little lean could be solved by syncing the carbs.
I know what you're thinking -- just a little too high? It's 4 times too high! How is a small adjustment going to fix anything?
The answer lies in the way that the carb'd monsters handle ignition timing. Instead of having a curve that progressively advances the ignition timing with increasing speed, the stock ignition system is basically all or nothing. The flywheel has a metallic bump on it, which looks kind of like a wheel weight but smoother and more permanent. The pick up coils send a pulse as this bump passes by. If the rpm is below a certain point (I think 1300 or 1400 rpm), the ignition system fires a spark at the end of the pulse. When the rpm goes above that level, the ignition system switches to firing at the beginning of the pulse. So the timing is fully retarded below 1300, fully advanced above 1300rpm.
The problem that I think you're seeing is that now that your carbs are healthier, the bike wants to idle a little faster, which pushes the idle rpm just above that threshold level. When the idle is set above that threshold level, because the ignition system moves to full advance, the engine really takes off and settles at about a 3-4k rpm idle.
It could be something else, of course (like a vacuum leak or a problem with the throttle cable), but I have seen this problem come up a number of times on the forum and be solved by a small idle adjustment.
Could very well be. I had it backed way off initially where it wasn't even touching. It did jump a few times down to about where it would almost die and climb right back up. I think I counted 2 1/2 turns to up the idle and then it just took off. I got a lot of popping out of one muffler too and one was running hotter than the other. The header crossover is still there. It's not individual pipes except before and after the x-over. I got a temp gun to make sure. If it is a vacuum leak that means a lean condition correct? The front header seemed like it was a lot hotter than the rear. Which could explain the difference in muffler heat difference. I know I need to take them back off and clean the throttle return spring and all the little stuff around there. I may go have them dipped for good measure. Haven't decided yet.
Are you sure you're turning the idle speed adjustment screw, and not the synch screw?
Ya. I eyeballed that one while the carbs were out. With them on that screw is way up in there. It's the idle screw for sure. I'm going to hit the headers with a temp gun after a decent warm up to see if I'm right. If I'm having trouble I bet it's the front cylinder. DP, I don't have a problem verifying they are in sync but that means a 30 minute ride to the shop I'd have do it. If I'm going to that much trouble ill just have the carbs gone through all the way and be done with it just for the sake of possibly doing a number on them myself.
After I try the temp gun ill try backing the idle screw all the way off and see if that changes.
As suggested by bond0087 the new parts will change the running enough to warrant a thorough set-up of the carbs.
Setting float levels would have been a good idea while you were in there.
It might not be a bad thing to let the shop check things out.
I totally agree. It's not a duc shop though. Nearest one is 2 islands over in Honolulu. That pretty much sucks. But these guys have more equipment than I do and all the sport bike guys over here go to them.
The float levels would have been nice but I haven't found my vernier caliper yet(still in a box) and I had to go to work. I did what I could for the time I had. That won't happen again. I know everything needs to be cleaned good but I don't have a place to do it yet (carport). I'll just go get it worked on and be done with it. After I fiddle a little bit.
Started it up and ran for 2-3 minutes and hit the headers with a temperature gun. Front cylinder measured just over 700 and the rear was like 330. Looks like the carbs come back off soon.
CV carbs are fairly easy to deal with. You definitely need new emulsion tubes. I suggest the nickel plated ones from Factory Pro.
Cleaning is easy. Remove the bowls and diaphragms and brass jets (carefully). Get a big tupperware and a gallon of name brand Pine Sol. Soak everything for 8-12 hours then scrub and rinse. Pine Sol is rubber safe and really eats old gas, oil, and varnish. Blow out jets with carb cleaner. No carb cleaner on any rubber parts!
Float bowls can be set with a small ruler. Plastic float frame giving you trouble by popping up? Install the float lid with two screws so it hangs off the back of the carb body, thus holding the plastic float frame in position.
Just my .02 if you wanna do it yourself and save some time and money.
I already installed the FP emulsion tubes. Fairly easy. I just got cable today so I can use my laptop in the carport. Looking at pictures and tutorials on my phone sucks. Thanks for the pine sol tip. The shop I talked to said a half hour shop time to dip and clean them.
What's the best way to adjust float levels?
check out www.ducatisuite.com (//http://), particularly this page: http://ducatisuite.com/jetkit.html (http://ducatisuite.com/jetkit.html) Scroll down about 3/4 of the way to where he's measuring float height.
You want to make sure you measure at the first "sitting" point of the floats, and not the second, where they sit down further into the bowls.
Here's part of the problem. Would this cause a run away idle?
(http://i153.photobucket.com/albums/s236/grubbywarrior/A54CFAD8-8616-43E8-B331-ABC1DB5D1A94-8600-00000C0764395CB8.jpg)
Quote from: GRUBBY on July 20, 2013, 02:52:59 PM
Here's part of the problem. Would this cause a run away idle?
(http://i153.photobucket.com/albums/s236/grubbywarrior/A54CFAD8-8616-43E8-B331-ABC1DB5D1A94-8600-00000C0764395CB8.jpg)
It
is a vacuum leak.
It usually causes poor acceleration and fouled plugs.
I'm pretty sure it happened when I changed needle jets. That's off the front cylinder side. That's the one that was running 2x hotter than the other cylinder. Now I just have to find a new diaphragm.
Not sure of the cost stateside but from Italy the diaphragms are 98 euros.
For 110 euros you can buy a new set of carbs
http://www.ebay.it/itm/CARBURATORI-CARBURETORS-DUCATI-MONSTER-MIKUNI-38mm-/380676933264?pt=Ricambi_e_Accessori_Moto&hash=item58a21d0690&_uhb=1 (http://www.ebay.it/itm/CARBURATORI-CARBURETORS-DUCATI-MONSTER-MIKUNI-38mm-/380676933264?pt=Ricambi_e_Accessori_Moto&hash=item58a21d0690&_uhb=1)
Diaphragms are expensive here too.
Someone just found a source for a better price.
Let me look.
here... http://www.ducatimonsterforum.org/index.php?topic=61712.msg1156208#msg1156208 (http://www.ducatimonsterforum.org/index.php?topic=61712.msg1156208#msg1156208)
Quote from: ducpainter on July 21, 2013, 04:36:09 AM
Diaphragms are expensive here too.
Someone just found a source for a better price.
Let me look.
Yamaha dealer? TDM850
Maybe give SUDCO a call? http://www.sudco.com/ (http://www.sudco.com/)
Quote from: ducpainter on July 21, 2013, 04:36:09 AM
Diaphragms are expensive here too.
Someone just found a source for a better price.
Let me look.
here... http://www.ducatimonsterforum.org/index.php?topic=61712.msg1156208#msg1156208 (http://www.ducatimonsterforum.org/index.php?topic=61712.msg1156208#msg1156208)
Just found out about the DR650's yesterday. Yamaha parts fiche shows theirs as slide and all. $270 is what I was told for one assembly. Hell no. I'll sell off my old parts and one of 4 guitars and get FCR's before I take one in the butt like that.
+1 on SUDCO .
If not theres every chance a forum member will for a good price.
Mind you, nows your excuse for those FCRs! :D
Quote from: koko64 on July 21, 2013, 05:04:26 PM
Mind you, nows your excuse for those FCRs! :D
That's on my long term list. With a baby coming the 24th I gotta be on the cheap for a while.
Tried looking at sudco. What exactly is the nomenclature of these carbs? AFAIK they're Mikuni BDST 38mm carburetors. If they're there I didn't see if its called something else. The Yamaha dealer here (fz1000) said $270 and the Duc dealer in Honolulu said $175. But that's for the diaphragm boot AND the slide, which I don't need. Plus I figure I might as well get 2 and be done with it.
Did you look into the Suzuki part?
I stumbled across these guys a while back, and bookmarked them.
http://jbmindustries.com/Dimensions.html (http://jbmindustries.com/Dimensions.html)
Haven't searched their site yet for ones that fit, so maybe a red herring.
Quote from: ducpainter on July 24, 2013, 05:22:51 PM
Did you look into the Suzuki part?
His mechanic took my number in case he ran across anything but he said the same thing Yamaha and Ducati said. Slide and all. He's the one that called Oahu for me.
Quote from: Speeddog on July 24, 2013, 06:29:49 PM
I stumbled across these guys a while back, and bookmarked them.
http://jbmindustries.com/Dimensions.html (http://jbmindustries.com/Dimensions.html)
Haven't searched their site yet for ones that fit, so maybe a red herring.
Thanks. I'll look into that one.
I can get Suzuki diaphragms local I found out today. Not from the dealer. He didn't want to touch them. If they're the same part number through Mikuni then I'm in business. DP, thanks for that link that says they cross reference. I'm pretty sure it'll work but I wanna make absolutely sure.
I found this place today. Might help out some others looking for the same thing I am. 22.50 euro which translates to $30 per.
kedo.com/products/41454.html
OK, so here it goes...
I can confirm the Suzuki DR650 diaphragms work. Done.
But, the floats had me scared to death. I've never ever had good luck with carburetors. Auto OR moto. But after reading reading the FP and Ducati Suite pages on adjusting floats, it seems a lot easier than it reads. Here's what I did. Please tell me if I did this procedure correctly.
1.Stood carbs on the vacuum chambers so the floats pivot freely when moved.
2.Rest floats on the flat needles as not to compress the springs inside.
3.Take measurement. (I got 12mm on both sides.)
4.Push tabs down to make resting float depth higher.
5.Take measurement. (I got 14.00-14.10 on the first try)
Now, that being said, how critical is the .10mm ? I guess it's just a matter of trying out some fresh gas and giving it a go to see what happens.
And as far as balancing carbs go, I know its crucial, but is it sufficient to go off of sound initially? I've played guitar for 23 years so my ear is pretty tuned to subtle changes in pitch. If I'm off by a little bit without using a manometer, it's not going to fry the motor, right ? In other words if I can get it pretty close by ear will that buy me enough time to ride 16 miles downhill to get to a set of gauges?
I'd be happy with your results on the floats.
You can run a bike without the carbs being synched. It won't fry anything.
You'll find out how good your ear is when you hook up the manometer.
Do you have nipples for the intakes?
I do. Not on the bike but in my spare parts bag of bolts and widgets. That's one of the must have items to keep out of all the other things I've taken off over the years IMO.
You need something to attach the manometer tube to. [thumbsup]
Motion-Pro sells some slick extended ones if the need ever arises.
Awesome. Thanks for that info. I'm just hoping it runs better and I get my idle back. While I was at it I backed the idle screw off to start from zero again. As long as I don't get one cylinder running 2x the exhaust temp and a 4k rpm idle I will have considered this to be a successful endeavor.
Success!!! Except now it feel like it wants to pull a little bit going from under load to no load and it's a bit sluggish just off of idle. Is that a balance issue? That's the one thing I haven't done yet.