| Author | Message | ||
     Burrpenick |
My '02 Cyclone with forcewinder and V&H pipe is still coughing occasionally at lower rpm under a load. It doesnt seem to cough just revving at a stop. I've modified the forcewinder and tried adjusting the idle mixture screw, but I still get this annoying cough. My slow jet is a 45, using the NOKH needle and the main is a 190 I believe. I still have a 195 & 200 in the jet kit. I found the idle screw out 2.25 turns made it cough the least. I am about fed up here......the cough is very unsettling when corning. HELP! | ||
| Koz5150 |
I was havig the same thing with the same set up, different slipon exhaust though. I just dropped my bike off for a dyno tuning session. I hope it fixes it all. (not to mention the last dyno pull my bike did was 64 HP???) | ||
| Captainkirk |
I found a real easy way to fix this...chuck the CV40 in the gravel and bolt on a Mikuni. You won't be sorry. Really. The HSR42-11 kit is a bolt-on, uses your existing cables, and can be had on ebay for around $270.00. I think retail is around $350.00 or so. Eastern Performance Cycles sells them on ebay but also direct(for more money, obviously).I'm sure American Sport Bike has them as well. I GUARANTEE this will rid you of the "Keihin Cough" for good. The Thunderslide kit also helped mine immensely, though not completely. | ||
| Sandblast |
It's weird. Mine coughed like crazy stock, but I put a 45 slow jet in her, it came with a 195 that I left alone, and I have not touched the idle screw, and she has not coughed once in a long time. This is with a Hypercharger and a Carbon fiber Borla slip on. Is it really cold where you are lately? | ||
| S2pengy |
If it just started check the manifold seals..... Some suggest changing these once a year.... | ||
| Bluzm2 |
Is yours a 200 or a 2002? Your profile says 2K. Not that it really matters... How many miles on your bike? Like Pengy said, it could be a slight intake leak. Check it with WD40 while the motor is running. Spray it around the manifold seals and see if the idle changes. Do it with the motor cold and warmed up. | ||
| Burrpenick |
Thanks all who responded. My '02 Cyclone has 9800 miles. The Mikuni sounds good, but I dont think I will go that route. I'm too cheap or poor one, but I also like to fix things, and it seems that lots of folks run the originals w/no problems. I plan to check out the leak around the carb manifold next. I am even considering trading it.....maybe a 'new' Triumph twin? penick@nettally.com | ||
| M2nc |
Up your slow jet to 48. A stock Blast jet will do. I did it on my M2 after the V&H pipe and it really improved. I left the High Speed jet alone. It wont go 100% way, but close to 95%. | ||
| Tim |
The forcewinder has been known to cause carb tuning issues. It has been discussed at length in the knowledge vaults. | ||
| Newblaster |
M2nc--A stock Blast jet is a 42, not a 48. I don't think they make any others. When I upped my slow jet to a 45, I used a Sportster one. | ||
| Koz5150 |
Well Dave just notified me with the results of my Dyno Tuning. 5/14/04 67.69 HP 69.07 Torque 3/9/05 78.2 hp 77.5 tq I will pick up the bike tomorrow and can give more details then. 77 days till my trackday at Blackhawk!!!! BOO-YAH!!!! | ||
| Rick_a |
48 low jet is H-D PT#27165-90. | ||
| Tramp |
intake AND exhaust leaks can give you a cough. i noticed above that sandblast mentioned changing jets and that fixed it. often this occurs when the carb is removed for the jet change (which, as we all know, is not always 'neccesary'). often a carb which had some blowby prior to removal gets the blowby inadvertantly repaired upon reinstallation, so the cough disappears. (Message edited by tramp on March 13, 2005) | ||
| Bluzm2 |
Jay, I've been exchanging a few emails with Burrpenick. I've got him checking both intake leaks and exhaust leaks. For others interested, exhaust leaks at the head and the muffler slip joint can cause popping and or coughing. I keep a spare set of intake seals, carb boot and exhaust gaskets on hand just in case. Permatex high temp red takes care of the slip on joint. Aren't these old tractor motors fun to work on! Just adds to the "character". Brad | ||
| Tramp |
absolutely, brad. incidentally, spraying staring fluid (LIGHTLY) around possible exhaust leaks can tell you plenty, too | ||
| Tramp |
ummm.. i meant "starting" fluid. ya spray that "staring" fluid and you'll just gape at it all day and get nothing done.... | ||
| Mr_grumpy |
I cured my 99 M2 with a 45 slow jet & a 1mm washer under the needle to raise it slightly, I also bored out the air-bleed hole in the slide to 3mm, so it moves a little faster, been no problem since. | ||
| Tramp |
...betcha removed the carb to do that, too  | ||
| Newfie_buell |
No Way, I have seen him straighten a bent convertible top rib with a piece of board, a framing square and a couple C-Clamps!!!! | ||
| Bluzm2 |
That staring flud really stings the eyes too! Grumpy, I also told him about the needle shim except we're not metric around the parts.... told him to find a .050" shim washer at a hobby store that handles RC cars. They use them in motors... | ||
| M2nc |
NewBlaster - If I am mistaken it is because of Ayden. The closest I have been to a Blast was a ten mile ride on Ayden's. We used what he stated as the stock Blast jet. The M2 stock jet is 42, this one was clearly marked 48. He may have confused it from some in the jet kit he got for the Thumper after putting the "Race Kit" on it. Still the 48 did the trick. I just got back from Daytona on the M2. Rode 1200 miles or so and it coughed three or four times the entire weekend, usually when the motor was still warming up. The highest temperature was 84°F, the lowest was 35°F. The only constant was elevation. From NC coast to Florida there is really not much change. | ||
| Aydenxb9 |
M2nc-the 48 I put in your bike was for the Blast!, I never said it was the stock jet. I had played with a 48 and a 45 trying to get the tuneup right on the Blast! after doing the exhaust. | ||
| Newblaster |
Good to see it's all cleared up. lol... BTW, I wasn't trying to correct you or anything like that, just wanted to be sure nobody put a stock Blast jet in without checking it, thinking it was a 48. | ||
| M2nc |
Newblaster: it's cool, I always blame Ayden for my screw ups. You would think that after a quarter of a century he would know that.  Obviously I misunderstood. Either way the 45 really didn't fix it when we were trying to get the cough out of my M2 after adding the V&H. One great side-effect of the 48 jet, is very quick throttle response. Much better than stock.  | ||
| Aydenxb9 |
I think that even a 48 might still be just a little too lean. I'd still like to try a 50 or maybe a 52 to see where it falls off. As far as Kehins go, the one on M2nc's '99 seems to work pretty well over all. Checked the seals at the time I re-jetted the carb and all was fine but it has been a while. I wish the one on the wife's '05 883C worked half as well.......... | ||
| Burrpenick |
Still Coughing George here......just looked at the plugs, they were burning whiteish, but there may have been a tan tint too, maybe hinting at leaness? I have a 48 slo jet from my Kit, so maybe I should try that, after I screw out the idle mixture screw a 1/4 turn more? Can I get that jet changed with the carb on? | ||
| Aydenxb9 |
Plugs are saying your close but a little bit lean. The idle mixture screw isn't going to make it any richer, it will make it leaner,as what your doing is adjusting an air bleed. It is easiest if you at least pull the carburetor out of the intake, as the frame makes it more difficult to get the bowl off. Also, when your trying to remove the slow speed jet, the frame gets in the way of the screwdriver. Trust me I've been there, done that and have 2 modified screwdrivers to prove it. | ||
| Bigj |
I ran a 50 slow and 200 main, along with a Dynojet needle and slightly drilled slide, in my '97 Cyclone. Was the best carbuerating Buell I've been on. A/F ratio was spot on. Screw the 45. I'd start with a 48 and go from there.  | ||
| Ivershay |
i work at a dealership (i know - boo hiss) and i have to agree with CaptK - chunk the cv and bite the big one on the mikuni. first thing i recommend to any customer considering a performance mod. best bang for the buck.  | ||
| Burrpenick |
{}I am now armed with more info that I have time to use....but, I am going to pull the carb loose and install the 48 slo jet that I already have, and hopefully that will be the end of my problem.}} | ||
| 5287626 |
I found the fix for the forcewinder. The cause for the mid to high RPM power loss is that the fuel chamber in the CV is vented through a venturi in the 1:00 position on the intake flange. This oraface is matched with a port on the forcewinder. The problem is the fuel chamber vents through the air horn (body) of the Forcwinder, as the the motor revs it needs more air. When it vents through the air intake it is trying to vent to a vacume environment. The fix is to drill a small hole in the forcwinder body (1/8" at the boss on the forcewinder flange at the vent. If you make a dyno run before and after you drill the hole you will see a significant difference in HP. The carb will now vent to atmosphere. Steve | ||
| Burrpenick |
How about a pic? Anyone else tried this? | ||
| Bluzm2 |
Stephen, That's not quite correct. There is no vacuum in the intake tract. It is atmospheric pressure. The same a you and I breath. The open intake and decending piston create a low pressure that causes atmospheric pressure to push the air through the carb. There is no need to drill a hole through the outside of the Forcewinder. Simply enlarge the existing missplaced and too small air vent channel. The "atmospherics" on the inside of the Force are no different than a velocity ring inside of a race can. The velocity ring has a hole drilled right over the carb bowel vent. It's purpose is to vent the float boal to atmospheric pressure. Exactly what's inside the intake in front of the carb. | ||
| Rick_a |
The CV can be pretty responsive tuned correctly. I've seen a few carbureted racebikes with CV's on 'em. The main thing I don't like about the CV is that there isn't a very linear feel in respect to the throttle position. BTW the idle mixture screw on a CV is a fuel mixture adj. not air. The Mikuni uses an air screw. |
