Author |
Message |
Revperry
| Posted on Tuesday, August 11, 2009 - 09:14 am: |
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My Cyclone shop manual indicates the stock jets are 42 slow & 200 main (Keihin 40mm carb). Recently, a Forcewinder AC & Vance & Hines exhaust were added. Problem: popping on deceleration and poor highway running unless I pull the choke out a little, then it smooths out. I think this indicates a lean mixture condition, especially at higher speeds. Keihin's website the 200 main is as big as they go, so what should I do to richen up the mixture for high speeds? I'm a noob so all advice will be gratefully received. revperry '00 Cyclone '85 Honda Nighthawk 650 '07 Lance Vintage 150 Scooter (way fun!) |
Buell_bert
| Posted on Tuesday, August 11, 2009 - 01:58 pm: |
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Have you checked the intake seals? This would cause a lean condition I would think. |
Revperry
| Posted on Tuesday, August 11, 2009 - 02:05 pm: |
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Yeah, I just had the intake seals changed about a month ago; however, I'll go back & re-check that & other possible vacuum leaks. The bike is in the shop for tires so when I get it home I'll pull the plugs & see what's going on there. I've read about "plug chops" to check for lean conditions as well. Is my shop manual correct in stating the stock jets are 42 slow & 200 main? Seems to me others are saying they're going to 45 slow & 190 main after a Forcewinder & Vance & Hines slip-ons. |
F_skinner
| Posted on Tuesday, August 11, 2009 - 02:09 pm: |
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Check your plugs to see if it is indeed a lean condition. It sounds like a leak at the header or manifold like Buell_bert said. When was the last time you rebuilt your carb? |
Revperry
| Posted on Tuesday, August 11, 2009 - 02:44 pm: |
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O.K. When I get it back from the tire change I'll pull the Forcewinder & check the rubber seals/gaskets. This is a new (to me) bike____only had it a couple months so AFIK the carb has never been rebuilt. Sounds like I have a lot of stuff to do in the next couple days! Thanks for your help... revperry |
F_skinner
| Posted on Tuesday, August 11, 2009 - 02:59 pm: |
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When my bikes start popping I know it is time to tighten the exhaust flange, they will come loose. With the bike running spray wd 40, brake cleaner or something like that around the seals. If the rpm changes then that is your leak. Frank |
Bluzm2
| Posted on Tuesday, August 11, 2009 - 04:54 pm: |
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In the KV there is informaiton on a problem with new style Force intakes. The float bowl vent isn't big enough and will cause problems at higher RPM's. It needs to be ground out to a larger size. The KV has pictures... The pilot jet jet should be a 45 at minimum. A 200 main is a bit too big, most stock motor M2's use a 195 or a 190, some go even down to a 185. |
Kusskid76
| Posted on Tuesday, August 11, 2009 - 06:38 pm: |
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Maybe I'm being too obvious here but have you adjusted the mixture screw since you added the forcewinder and V&H I have the same intake and exhaust on 98 S1 and My mixture is at 3 1/4 to 3 1/2 turns out and have a 42 and 195 W slinger airflow recal kit needle |
Revperry
| Posted on Tuesday, August 11, 2009 - 10:45 pm: |
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Thanks for all the suggestions! I'm still wondering if the shop manual is wrong when it indicates the stock jets are 200 main & 42 slow? If, indeed, this is a jetting problem wouldn't a smaller main jet make the supposed lean condition leaner at higher RPM? But, first I'll check these other things and then address the jet issue. Thanks, everyone! revperry |
Blake
| Posted on Tuesday, August 11, 2009 - 11:32 pm: |
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Main jet won't affect cruise (low throttle, lower rpm ranges) at all. Replace slow jet with a #45 and set the idle air mixture screw to 2.5 turns out from full in. Ten years ago this was common knowledge here. Fuel injection ruins everything! Popping on decel indicates exhaust gasket leak. |
Revperry
| Posted on Wednesday, August 12, 2009 - 12:16 pm: |
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I'll be getting the M2 back today with new shoes so the 1st thing I'll do is check for exhaust leaks. Hopefully that'll stop the popping on deceleration. The 2nd thing to check will be the color of the plugs, and the last thing will be to remove the tank & check the manifold seals. I'll let you all know what shakes out of this thing in a couple days. Thanks, again for all the advice. I appreciate it! revperry |
Bluzm2
| Posted on Wednesday, August 12, 2009 - 05:27 pm: |
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You don't need to remove the tank to check the seals. Just a spraybottle of water, can of starting fluid or carb cleaner. With the bike idling, just spray it around the intake seals. If the idle changes, it's leaking.. |
Blake
| Posted on Wednesday, August 12, 2009 - 07:24 pm: |
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Use a fast idle, around 2000 rpm for best chance of finding a leak if one exists. |
Buell_bert
| Posted on Wednesday, August 12, 2009 - 07:40 pm: |
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To add to this is use a needle spray to the seals. If it is a mist it may still get sucked into the intake and give you a false sense of security on your diagnosis. This depends alot on your type of air cleaner. It also may help to use the extended tubes. Kind of like what they use on carb sprays. Keep us in the loop as to what you find. |
Bluzm2
| Posted on Wednesday, August 12, 2009 - 08:42 pm: |
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That's why I use carb cleaner. Nice straw and you don't need much to find a leak.. Ether on the other hand goes everywhere... |
Pammy
| Posted on Thursday, August 13, 2009 - 08:09 am: |
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Maybe you mean brake cleaner. Carb cleaner is a bit too harsh for rubber, paint. |
Blake
| Posted on Thursday, August 13, 2009 - 09:48 am: |
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Good call Pammy. WD-40 also works well as does plain old water in a mister. One of the more interesting compounds I've heard of folks using is propane. |
Al_lighton
| Posted on Thursday, August 13, 2009 - 03:25 pm: |
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You don't want to use any degreasing agent to check for leaks, which is why propane is good for that. A properly assembled manifold joint has been lubricated to allow movement at the joint when the jugs grow taller and move away from each other. Using a degreasing agent, especially one that attacks rubber, will not only strip the syl-glide, but can also make the seals gummy and cause leaks during that expansion. The service manual says propane, using a wand that has an HD part number. Your basic plumbing torch works fine, but you just need to crack the valve, don't open it up wide.... Al |
Buell_bert
| Posted on Thursday, August 13, 2009 - 05:25 pm: |
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You could probably use one of those extended grill lighters. Just don't light the damn thing while leak checking. Heck you can buy them for a buck at the dollar stores. |