Author |
Message |
Ratbuell
| Posted on Thursday, July 07, 2011 - 12:32 am: |
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This S2 is starting to piss me off. 95 S2, stock bottom end, Thunderstorm top end, X1 cams, bronze gear, XB rockerboxes, plain ol' bolts holding the carb bracket. Jetting is 45/200 as of today. It behaved exactly the same with 45/190 and 45/195. Stock carb. Actually...a brand NEW stock CV40. Intake seals are good. S1W race ignition. Stock S2 header, have run with both Supertrapp muffler and with Kerker "Series K" can. No change. New plugs (6R12) and wires while trying to troubleshoot this. Grrrrrrr. What it does - runs like a raped ape at anything up to 90% throttle. Anything over 4500rpm, if I twist that last 10% out of it...it starts to misfire. I'm stumped. Am I looking at VOES? Bad ignition box? Grrrrr..... |
Ratbuell
| Posted on Thursday, July 07, 2011 - 12:34 am: |
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Forgot to mention - this configuration has run flawlessly for three or four years. No major changes to the setup to "cause" the hiccup. Grrrrrr. |
Ft_bstrd
| Posted on Thursday, July 07, 2011 - 12:39 am: |
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Throttle cable linkage is good? Could it be something simple like that? |
Jacob83z28
| Posted on Thursday, July 07, 2011 - 12:44 am: |
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Make sure the vent coming off the carb isn't blocked. |
Ratbuell
| Posted on Thursday, July 07, 2011 - 12:59 am: |
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Cables are good, no issues or bind. Going from 90% to 100% throttle over 4500rpm induces a misfire. Up to 90%? It runs awesome. No hiccups, no power dips or surges. The ONLY thing I can think of that would cause that - since there's no TPS on a carb to send a "bad" signal to the ignition box - would be the VOES? Jacob - same issue, 2 carbs. All it/they have is one capped fitting, one hose to the VOES, and the overflow hose. The fourth hole at the air filter mount plate is clear if that's the vent you're talking about. |
Jacob83z28
| Posted on Thursday, July 07, 2011 - 01:09 am: |
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I guess it's the overflow I was talking about. My Cyclone was doing something similar at the 5,000 and above RPM. I took it to a harley mechanic, not a dealer, and he found it blocked. I never had that problem again. The only other thing I can think of is timing. Have you checked or adjusted the timing? |
Sanders
| Posted on Thursday, July 07, 2011 - 03:07 am: |
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Sounds like a timing issue. If I remember right the VOES retards timing when it senses a vacuum. It's possible it could be malfunctioning. You MIGHT be able to disconnect the VOES and see if it is still doing it. Also it could be leaning out... |
Fahren
| Posted on Thursday, July 07, 2011 - 07:56 am: |
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Joe, this may have nothing to do with the issue at hand, but the 6R12 plugs are a NO-NO for Buells. They were superceded by the 10's, and there was a service bulletin (or something official like that) to that effect. I don't know the reason for the change, but the spec that's still in the manual is no longer the right one. |
Edv
| Posted on Thursday, July 07, 2011 - 08:32 am: |
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Be sure your tank vent is open, I occasionally find this to be the problem and will show up at wide open throttle |
Ratbuell
| Posted on Thursday, July 07, 2011 - 06:57 pm: |
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Yeah, thought about disconnecting the voes. Timing is good since it does fine EVERYWHERE except right at 100% throttle. I'll change the plugs, thanks! Tank vent is clear. I'm VERY familiar with that one and I doubt its leaning out since it has, in this exact configuration, run fine before with a 45/190 and it has a 45/200 in it now. Something "broke", I just need to identify it. |
Fahren
| Posted on Thursday, July 07, 2011 - 08:07 pm: |
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Oh, and by the way, I want to know about those roads where you can get away with 100% throttle in MD!!! :-) (Not in 1st gear, of course |
Bluzm2
| Posted on Thursday, July 07, 2011 - 11:02 pm: |
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Rat, It might be one of your relays that hides behind the battery. I had the same thing happen to my 95 S2, odd as hell. Fireman Jim has had it happen too. I think it happens when the motor hits a certain resonate vibe level that a weak relay doesn't like.... You can pick the relays up at NAPA. I changed all of them and the problem has not recurred. Things that make you go "Hmmmmm". Brad |
Ratbuell
| Posted on Friday, July 08, 2011 - 01:01 am: |
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Fahren - same roads where I whacked the CR up to 118 according to the GPS. Passing *one* truck. whoops, heheh.... Seriously though, Frederick County (just south of Gettysburg PA) has some great rural roads and if you stay off the highways, are relatively lightly patrolled. Good visibility, good surfaces, and living here I know which ones don't have a lot of driveways or intersections |
Onahog
| Posted on Friday, July 08, 2011 - 02:12 am: |
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Rat... I run a 48 and a 190 in mine... i do believe you maybe too fat on top ... id try the 48/190 combo or a 48/185 combo.. Too much fuel at top wide open & slow down usually means too fat.. I no HDs that run beter and stronger at 7/8 throtle verses full throttle are too fat , decrease helps them out.. |
Ratbuell
| Posted on Friday, July 08, 2011 - 07:54 am: |
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Hank - it's not that it just falls flat...it stutters. Like a soft-touch rev-limit. Only in that last 5-10% throttle. 45/190 has, in the past, flat SCREAMED in this bike. I tried the 200 to see if that was "it"...its not. I have to chase other than the jets, I think... |
Onahog
| Posted on Friday, July 08, 2011 - 12:03 pm: |
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Ok...Then my next step would be ignition module or perhaps the coil is running a tad short on heavy demand.
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