| Author | Message | ||
     Briansubsist |
i'm looking between a mikuni 42mm or the cv44. i already have the manifold intake kit. i'm running the force exhaust with the race ignition module and pro series air cleaner. anybody have any opinions they would like to weight in on? i'm afraid i might actually loose some power with the cv44 with no engine work done. decisions decisions. any help would or advice would be greatly appreciated. thanks in advance. brian | ||
| Aaron |
Mikuni. No comparison. | ||
| Blake |
Brian, Is your engine otherwise in stock form? Without ported heads or big bore what are you looking to gain with a bigger carburetor? Cause it won't be much. I'm pulling 100rwhp through the stock CV40. Suggest you spend your money where it will do the most good. | ||
| Aesquire |
M2 guys, Little hint (prob. not new) I did the 45 idle 2 1/2 turns thing, runs MUCH happier now, sorry I even waited for the 500 mile thing. When I drilled out the plug on the idle screw, I started to clamp it in a vise (padded) for the drill press. What's left of my brain said "where do the chips go?" so I used a battery drill (slow) with a sharp bit ( 'cause dull bits hurt you) drilling up at an angle so chips fall away from delicate carb innards. Pulled plug w/drywall screw (oh, thats too easy). Some locktite & never-seize, happy happy joy joy. pics & tips (Message edited by aesquire on May 10, 2003) | ||
| Xb9 |
Questions on the XB DDFI system: I plan on periodically switching mufflers from a Latus (around town) to a modified stock muffler (day trips, touring) on my race ECM equipped XB9R. Obviously, these two mufflers have different flow characteristics. Question is, will the periodic switching of mufflers cause problems with the fuel calibration? (adaptive fuel value?) My thought is that the ECM will compensate back and forth between the two mufflers, given a few "rides", but I don't know if there is a long term affect that may "skew" the calibration. One other thing I have alway's wondered about, does the ECM (Stock or race)have the ability to change the curve of the A/F map? Or can it only shift the whole map up or down based on what the O2 sensor reads in closed loop? It appears that on a stock ECM, it can only move the whole map up or down, not change the curve. Is the race ECM different in this regard? | ||
| Blake |
XB9, I'm 99% on the following but you might want to verify it to be certain... The AFV will self calibrate upon changing mufflers. This is accomplished by taking a warmed up bike for a ride and holding rpm between 3,000 and 4,500 rpm at a relatively steady speed for a few minutes. A quick cruise down the highway ought to suffice. The ECM's may permit uploading of new curves (mapping), but not by you, me, or even the average dealership. The race ECM is no different than the stock ECM in that regard. If one had the right tool and the right software and the right access codes one could theoretically be able to upload/flash new mapping into any DDFI ECM. There were some guys looking into figuring out how to do that a while back. I guess they gave up. | ||
| Xb9 |
Thanks, Blake, appreciate your input. One area of confusion (to me) seems to be at what RPM is the best to ride steady for a period of time to allow the ECM to interpret and adjust to the O2 sensor value in closed loop. The XB service manual states in order for the system to enter closed loop operation, the following conditions must be met: 1. O2 sensor at operating temperature (engine at normal operating temperature. 2 Operation above 5,000 RPM under normal steady load conditions. You have said 3-4.5K, and I talked to a technician once that said you don't have to run it at 5K to have the ECM enter closed loop. Can anyone verify which is correct? Or maybe both are. According to the latest Fuell, there's an article on the DDFI system, and although it is not specific, the curve pictured looks like we're in the ballpark. It sure would be nice if more info was available on this system from Buell, but I can also see why they are somewhat tight lipped about it. Proprietary. The fuel management system on this bike is impressive. If we could only tweak our ECM fuel maps with a laptop.... that would be nice. | ||
| Blake |
EPA no likee. I would tend to trust the manual. I am probably recalling the rev range for the tube framers. I was definitely guessing. Drop her into 4th gear and cruise down the highway at 75 mph, you should be good to go. | ||
| Iamike |
After 3.5 years and over 30,000mi. I ran across a little problem my FI '99 S3 had. Ever since I've had this bike I've felt that it just didn't run right at idle or low RPMs. I've had 3 different dealers look at it and tell me "that's just the way they run". Well last weekend I decided to replace the intake seals since a couple people have had problems with theirs after this many years. When I pulled off the throttle body there was a little brass tube hanging out there that had no hose or cover on it. I refered to that all important service manual and it said it was for CA models and goes to an EVAC cannister. It also showed a cap on it (condum?). Anyway, I put a cap on it, cleaned the intake manifold (looked like crap) and put everything back together. Needless to say it idles much better with very little shake and doesn't jerk around as much at low RPMs. I really hate to criticize dealer shops but this is just another thing that they should have caught when my bike was in there. | ||
| Good_boy |
Hello guys. Been a while since I went on this board. So, I'm in great despair. I thought I knew a bit about engine and carburetion, but... A week ago I was crusing on a highway (about 90 mph, 4000 Rpms, then I heard an explosion from the exhaust pipe. Then a second. then.. a third and a whole family. cut down to 3500 rpms, wen well. Once arrived, I noticed that the air filter (stock paper element on stock airbox) presented a 2" hole, only wireframe. Well, this is it, i'm running lean because of that ! Replaced this faulty filter by a brand new one. And the engine wis still bangin. In full throttle in first gear (wheelie attempt...), and then in every gear, provided i opened mor than a bit the throttle. Say, 1/8 to 1/4. Let's see the spark plugs... Well, they were VERY white. So I purchased a pair of new 10R12. Same effectn, banging, and after a check, white too. I'm running lean. mayeb a small bit of air filter paper stuck in the 40CV carburettor ? Well, let's see. Carburettor clean. Rubber thingy from the top seems exempt of holes. Depressometer tubing seems to fit right, and rupper plug in the depression measurement thing seems to be in perfect shape... All the small ducts, piping and guts clean. Well, at least it let air pass trough, with air compressor check. Float bowl level ok too. Main jet #195, #42 pilot jet, 2 turns and a half on the idle screw. The classic settings... Air leak ? Cockpet thing ? I drowned it in wd40, no sign of the slightest air leak. Replaced the carburettor seal on the cockpet, same banging. Flooded the area where the cockpet lands on the heads, , no sign of increase or decrease in the rpms (did that on fast idle, about 2500 rpms). Ah. It's not the gas because I tried differnt ones. So what next ? I checked plugs, the spark seems to be a bit weak. But that would not give me bone white plugs. So what I think of is : air filter paper went in the engine, and ruined my exhaust valves seats, so I'm lean, damn lean. But that would also mean dramatic compression loss, and I would'nt be able to run at 90 mph, uh ? The engine is in this configuration for ages, like 1000 miles or more. Never went too lean. Has someone ever had such a weird engine malfunction ? Maybe a dented cockpet, or someting like that (close inspection did not showed any dents, but I have to disassembly it from the engine. And the wd40 trick should have showed it... So : stock 40 CV, stock airbox, slip on vance like muffler, 195 main jet, Sportster needle (N65C if I remember), 42 pilot jet. 2 turns and a half on the idle screw. Dazed and confused for so long it's not true... Wanted a good mixture, never bargained for... Please help, I'm losing the grip I had on my knowledge. Thanks for reading this, anyway. | ||
| Hoser |
Souhds like an electrical problem , such as ..... Cracked or loose battery cable Loose or cracked wire on the "HOT" post of the starter. | ||
| Rick_a |
A cracked or loose batt/starter wire would have wet the plugs with fouling/unburned fuel. It's either air coming in from where it shouldn't or not enough fuel. Maybe a fuel passage got blocked internally with debris? | ||
| 99x1 |
" the spark plugs... Well, they were VERY white." Try running with the choke on? Is the ignition advanced and pre-igniting? (Since both spark plugs are white, I would doubt it is exhaust valve damage to both cylinders) Does gas flow freely from petcock? Does it run better with the gas cap off? Is the carb float level to low? Is the float sticking up? Good luck; John | ||
| Good_boy |
Rick : I thought At first it was a fuel passage that got filled up with bits frome the *swallowed* air filter... But it's damn clean. I'll triple check with brake cleaner all the guts of this carburettor Plugs ain't fouled but showing a lean mixture. the engine starts quickly, responding very well to a push of the start button.... 99x1, I agree with you : very unlikely to have damaged both valves, with paper bits... Ignition advanced... Oh, It wouldn't dare to do that on its own, would it ? I'm on stock ignition settings since Dinosaurs left the earth, so.. I don't think it could self unset... And the problem is, As I felt, linked with throttle opening, not (that much) with rpms... Running with choke on doesn't do much. At least, nothing noticeable. Gas flows more than freely, soaked my shoes when I forgot to tun it off. The floater is moving freely and the float bowl level is perfect.... I also tried the gas cap trick... //I still mix up "manifold" and homemade words... sorry...// Thanks for helping me. Does any of you have a voodoo degree, or something close to magical skills ? | ||
| Eastexsteve |
Good_boy, Look for a vaccuum leak in your manifolds. | ||
| Knickers |
Check for a bad coil. Resistance across the plug gap goes up with increased cylinder pressure (throttle opening) I think. I just replaced a coil that would run ok at light throttle, but sputter when I opened it up. Kurt | ||
| Good_boy |
Kurt, thanks for your advice... I wish, it had been ignition module. I really wish it were... But when I tried the first diagnose thing in the manual, it worked. Manual says : insert a conductive adapter into spark plug cables and establish a 3/16 in. (4.8 mm) gap between adapter and cylinder head. (...) check for a spark between adapter and cylinder head. Well, I am pretty proud of the tool I made for the test (two layers of 2mm acrylic, and an electric wire glued to that. Perfect gap. Nice spark was produced on both front and rear plug adapters. Well, I'll have to look for the gremlin elsewhere. Maybe a super hidden WD40-proofed gremlin in the manifold... I'll try with unleaded or other spray. Maybe it will show a leak where WD40 flooding did just a smelly steam on cylinders. (when I spray, I really spray) Thanks for your help in The Great Gremlin Hunt. | ||
| Biebul |
I have had a rather frustrating experience... First of all, I've been reading through the posts on this site prior to performing the basic performance mods at the top of this category. I did suggestion #1 and #3 for my '02 M2 Cyclone. I'd like to thank all the tech savvy individuals that have spent so much of their time to post info to this site. My difficulty arises after I have reassembled everything. I was happy to at least find that the motorcycle started and ran  There are a few things that give me the indication that things are not running right. When I go to run the bike, I give it gas and it slowly revs down to idle (too slow for comfort). On backing down the enricher as it warms up, the bike jumps from about ~2100 to 1000 and wants to die so I have to pull the enricher back out. I felt very uncomfortable about how it was running so I didn't get to the point of operating temp. I'm also hearing a slight hissing sound from about the carburator (left side). I'm not sure how the bike is supposed to sound, but I'm partially concerned that the carb didn't seat properly on the rubber boot. Any suggestions? I want to enjoy the perks of making these changes, but I'm not so looking forward to getting back into dissambling/reassembling all that mess if I have to.  | ||
| Hoser |
Did you forget to hook up the VOES hose , by any chance ?? | ||
| Eastexsteve |
Biebul, It sounds like you have a vaccuum leak. I would suspect the rubber that mounts the carb to the manifold. If the bike is very old, it will tear easily taking the carb on and off. You can use a little vaseline on it when remounting. | ||
| Biebul |
It's looking like its the seal ring on the intake manifold. As I did a good part of the reassembling as the sun was going down (sucks living in an apartment complex), I didn't see that the seal ring had twisted on remounting the carb. I'm going to pull the carb again and probably replace the seal ring as it is probably damaged now. I'll repost again after it's all said and done. | ||
| Kahuna |
follks, i need your help. my X1, after running perfectly for the past 5000mi, has developed a cough!? alomost consistantly, whenever i roll off the trottle slowing down towards a light say, anytime i try to blip for downshifts, i get a cough in the intake. any ideas? thanks! K | ||
| Blake |
Possible intake leak. Set idle at ~2,000 rpm and spray contact cleaner or WD-40 liberally around each intake manifold seal (each cylinder head and the throttle body interface). If idle speed drops, you've found the leak. Have the seals replaced. | ||
| Eastexsteve |
I know I've asked this question before, but I got no response. Maybe now is a better time. In regard to an M2, does anyone know the diameter of the head (top) of a stock needle? Also, the diameter of the needle just under the head? | ||
| Aesquire |
Steve, when the dealer gets in the 190 jet, I'll mike it for you. (would you believe a H-D dealer has 200, 195 & 180 jets for a CV40 but not a 190?? (and says he's never had or sold them!) Am I the only one in Rochester that rejets his bike? Or the only one that doesn't go somewhere else for parts?)  | ||
| Philip |
my stock needle from a 99 m-2 measures .232in at the top or head and .114in just under the head. that is measured with a cheapo but made in usa one inch micrometer. | ||
| Blake |
Steve, I've got one in my briefcase but I don't have a mic or calipers. I'm curious... why do you want to know? | ||
| Philip |
sounds like he's thinking, a dangerous thing! | ||
| Dratner |
Ok, this maybe a hair brained idea BUT ...I am thinking of putting a Buell EFI system on my Sportster. What would be involved with this? Is the Buell EFI system any good? Any and all thoughts appreciated -Dan | ||
| Ocbueller |
Dan, I think the only major problem with the Buell EFI is having to use a "dealer only" tool, to set it. Otherwise I think it's great. SteveH |
