I have a 1994 M900 with the Mikunis.
I have two questions. The first, I have been wondering for a while but avoided asking because its mentioned often enough that I feel I should have figured it out just be reading around by now. But I haven't.
1) Where EXACTLY is this vacuum shut off component? Part of the carb? Along the fuel line? Before/after pump? Unless its integral to the carbs, I don't think i have one.
2) Is there a cheaper place to get the main diaphragm assembly? I can get it from my dealer for $111 but I see now that the rubber piece is detachable. I feel like i can pick just that up for cheap! The main diaphragm controls the jet needle and is torn on mine. So I have a nasty mid throttle hesitation.
thanks
If you have a vacuum shut off it is here:
(http://i298.photobucket.com/albums/mm276/hlep2890/bike/IMG_0207-1.jpg)
I think your '94 has a manual valve.
You might try SUDCO directly since they are a Mikuni importer http://www.sudco.com (http://www.sudco.com) or your local Yamaha dealer since they used the same carbs on the old TDM.
Yup, manual shutoff.
Thanks for that pic!
OK, also I need to ID the needle I have in my carbs.
I spoke with DynoJet and Factory Pro. DynoJet needles have 6 positions and Factory has 5. My needle has 7 positions.
Does anyone know what brand a 7 position needle is? I plan on installing it the same way as a DynoJet would be.
(Plastic washer, eclip, metal washer, plastic adapter, spring)
Quote from: avizpls on September 08, 2010, 03:30:14 AM
OK, also I need to ID the needle I have in my carbs.
I would suggest that you throw them out and get a set of needles from Factory Pro. Then you'll be sure that you have the right ones. They worked quite a bit better than the stock needles in the Monster that I used to have.
well they're definitely not stock. I understand the stock ones have no adjustment positions.
Quote from: avizpls on September 08, 2010, 03:30:14 AM
OK, also I need to ID the needle I have in my carbs.
I spoke with DynoJet and Factory Pro. DynoJet needles have 6 positions and Factory has 5. My needle has 7 positions.
Does anyone know what brand a 7 position needle is? I plan on installing it the same way as a DynoJet would be.
(Plastic washer, eclip, metal washer, plastic adapter, spring)
I had an older Dynojet kit and the needles had 7 notches. The current kit has 6 notches on the needles when I compared them.
The taper is a little more aggressive on the DJ needles than the FP ones. Both kits are excellent for the compromise that is the stock Mikuni CV carb. The DJ springs are also softer letting the slide open faster. If you are not sure, buy the FP kit coz it's got Ti needles which should last, and make sure to get FP needle jets as they will last being stainless rather than the stock ones which oval out and cause rough, rich running.
Check your main jets they may have a little "dj" scribed on them and that will tell you. The jet numbers will also be different (larger). The DJ jet sizing system does not match the stock or FP system. There is a good chart on this site you can search for.
If you are short on cash, buy the FP needle jets and fit them.
Oh and reading the numbers on the main jets may require a magnifying glass if you're over 40! 8)
When I saw the difference in notches I asked someone who had long term experience with both types of kits.
Quote from: koko64 on September 08, 2010, 04:57:32 PM
Oh and reading the numbers on the main jets may require a magnifying glass if you're over 40! 8)
I use the SuperMacro setting on my Canon camera for that.
This is the microprinting on the back of a $5 bill as an example of how small it can photograph:
(http://i25.photobucket.com/albums/c67/scottrnelson/SLO/Img_0157sm.jpg)
I have photos of jets too, but not handy right now. A couple of days ago I had to find out what odds and ends of jets I had for a Honda XR and had to get out the magic camera to see the numbers.
G'day Scott
I could use a gizmo like that! (I still think we need an old fart smiley).
Avispls
I was thinking about what other mods have been done. You know, pipes, air box/pods. Since the bike sounds like it came to you with the jet kit, you may want to look up the DJ site and scope the instructions that come with your models kit. Then you could check out the recommended needle pos-ns and main jet sizes for the level of mods you have without buying a whole new kit. When comparing the new and old DJ needles, (the notches are counted from the top), the 1st notch on the 7 notch needle was the extra one, so count from notch number 2 when looking up the specs you should run. They got rid of that first notch on the new version of the needles. In other words, the old number 2 notch is the new number one.
If your main jets are not correct according to the suggested specs, then you could buy the equivalent jets from someone on the Forum for next to nothing or a local store. Just remember that stock Mikuni jets are numbered different to the DJ jets.
If your bike has shiny, stainless looking needle jets, then leave them. If they are the stock brass ones, then change them to the Factory Pro stainless ones, best thing I ever did. I went through two sets of stock needle jets in 10,000 miles.
Oh, and set your float levels to 14mm. They can be way out from the Ducati factory. The Factory Pro and Ducati Suite sites show you how.
Just sayin'.
Quote from: koko64 on September 09, 2010, 05:44:27 PM
G'day Scott
I could use a gizmo like that! (I still think we need an old fart smiley).
(http://i25.photobucket.com/albums/c67/scottrnelson/SM/oldguy.gif)
[clap] [clap] [clap]
Dear Moderators
May we please have an ol' fart smiley made available?
This would cater to the needs of a significant section of the board membership when giving advice to those "young people" (said with quivering voice). :)
Or when people want to bag others for being older. [evil]
Quote from: koko64 on September 09, 2010, 05:44:27 PM
<invaluable advice>
Just sayin'.
Awesome. Thanks for the tips. FWIW I'm "done" with this phase. I fixed the torn diaphragms and took it for a ride today. Its running better now than it ever has and it seems happy. I have a dyno sheet from when the diaphragms were presumably torn and it was lean in mid range, but ok at low and top. So I upped the needle one bump. I do not know what the Jet size is, and I don't know what type it is. I think its a 175, based on what a terrible shop told me (worst mistake ever paying someone to do work you should be doing yourself...but i didnt have a dyno) The part visible from the intake runner is brass.
I have a track day coming up and I don't want the bike to be in pieces for it. Ive been chasing this problem in the wrong direction so much and now that I found it I would rather play it safe and ride it thru the trackday. THEN I'll rip apart the carbs. Then it will be winter....
Thanks again and im going to go look up the dynojet recommendations now
Oh, and the mods Ive done so far are
Ignitek Ignition with Stock coils
pod filters
High Comp pistons (JE 11.5:1)
Light clutch and flywheel
Staintune low mount slipons
Nice mods. Similar to mine. That increase in compression wakes up the motor aright.
Cheers.
Oh yeah it does. Ive been dealing with this throttle hesitation since the build though, so Im only now REALLY experiencing the new motor.
Hey, I couldn't find the recommended settings based on modifications made. Do you happen to remember where exactly?
This kit is for Euro models E7206.001 so is a little different but is for "open air box with K&N filter, mild tune, aftermarket exhaust". Your DJ 175 jets are about the same as Mikuni 165ish.
EDIT: I checked out the US version of the kit and it recommends notch 5 out of 6. So you may need notch 6 out of 7!
The needle pos-n recommended is #3 from the top out of 6 notches. Make that 5 out of 6 notches. The needles are DNT730 ones. I think that your needle is set too lean as it would correspond to the first notch on the newer needles. My 7 notch needle was the same but for the extra notch. The taper appeared the same as did the length. If your needle is an old 729 it would be leaner in taper still. I think that some US models came with it but can't for sure remember. With this in mind I am not suprised that you have a lean hesitation. Your second notch pos-n is the leanest pos-n on the new generation needles. That will not help acceleration.
EDIT: The US stage 2 needles are 730 ones like mine.
Set the needle on the 6th notch and try it (6th from top). This corresponds to the 5th notch on the newer needles. I ran even higher needle pos-ns but my bike has significant porting on the inlet side. Test it with 50mph roll ons in 4th and 5th gear and see if acceleration improves.
Now I maniacally went through trying each needle pos-n with 50mph roll ons and 50mph cruising untill I was satisfied. I richened the needle (raising it) untill I was happy I had good acceleration, but I also made sure this did not cause rich burbling/missing at steady cruising which means you have gone too far and have to bring it back a notch. I don't recommend doing this as you can go mad! And get a ticket or crash. Dynos are a Godsend!
Check out the Factory Pro and Dynojet sites for tuning tips from experts and not backyard bums like me. I'd pop over with a few beers to help you out but I'm too far away!
Keep in mind that the stock carbs are a compromise and you need to settle for a balance between all out balls out acceleration which requires a lot of fuel suddenly squirted into the carb and a decently smooth steady cruising with reasonable economy between 45 and 70mph. They are not a flat slide carb with an accelerator pump which is a fuel 'water pistol' like device that will give extra fuel when you suddenly crank the throttle open. Stock carbs don't have them so dont expect instantaneous acceleration. Respect the carb for what it is and feed it in with a quick roll on rather than snapping it open.
An old bike tuner once advised me to "ride the carb".
I looked up the Dynojet site for a US stage 2 kit.
Ok the wash up of all that is try needle notch #6 from the top. If it causes rich burbling at steady cruising speeds then try #5. You should be close. I ran the same 175 DJ main jets with an open air box and aftermarket pipes which Dynojet also recommended. The Idle Mixture Screw setting suggested was 2 and a half turns out from lightly seated. As a rule, the fastest, strongest idle speed will tell you the correct number of turns (with a well warmed up motor).
Sorry for the confusion between Euro and US versions of the Stage 2 kit. We get the Euro kits in Australia.
Tell us how you go with it.
Now a question for everyone, is it different fuel or different calibration of internal drillways, that results in the different needle positions recommended by Dynojet for the same needle (DNT730) on US and Euro spec bikes. I reckon our fuel is different but I've been told that US carbs are slightly different internally.
Excellent, thank you. Right now I am on position 4 of my 7 (like 5/6 on the new ones). Im saving all of the info here thanks!