cbrbear Posted June 16, 2008 Share Posted June 16, 2008 OK so after not running for a year and before it ran perfect, I went through the carbs cleaned and re jetted. Got the bike running and it runs like crap. idles fine but once off idle it keeps falling flat on its face. sometimes it hooks up and just screems but then it misses and bogs out and almost completely stalls then you let it idle for a minute and it will run but with a very small throttle opening and hardly any power. The diaphragm in the pet cock is fine ( i replaced it anyway) plugs are new ngk iridium properly gapped. main jets 142, pilot jets are stock, af mixture screw is at 3 and I have gone many different ways but the same happens. Is it electrical? What could be going on? Almost just seems like the engine is starving for fuel but I know its not. HELP before I have to take it to a professional....lol Quote Link to comment Share on other sites More sharing options...
CxBXR Posted June 16, 2008 Share Posted June 16, 2008 Have you checked the coils to make sure they are within spec ? Could be weak spark & not able to ignite alot of fuel at once ? What do you mean properly gapped iridiums ,they are not made to be gapped, are you sure you didnt F**k up the electrodes ? Hope to help Quote Link to comment Share on other sites More sharing options...
cbrbear Posted June 16, 2008 Author Share Posted June 16, 2008 Have you checked the coils to make sure they are within spec ? Could be weak spark & not able to ignite alot of fuel at once ? What do you mean properly gapped iridiums ,they are not made to be gapped, are you sure you didnt F**k up the electrodes ? Hope to help The plugs came pre gapped I just wanted to throw that out there case someone asked. I havent done anything electrical and I would see why coils would just fail. The bike only has about 10K miles on it. I dont have a meter or anything to check electical stuff.... I am wondering if it is a plugged fuel tank vent but I dont have a hose attached so how do you blow that line out from the tank. Possibly stuffed up after being painted??? Quote Link to comment Share on other sites More sharing options...
CxBXR Posted June 16, 2008 Share Posted June 16, 2008 Have you checked the coils to make sure they are within spec ? Could be weak spark & not able to ignite alot of fuel at once ? What do you mean properly gapped iridiums ,they are not made to be gapped, are you sure you didnt F**k up the electrodes ? Hope to help The plugs came pre gapped I just wanted to throw that out there case someone asked. I havent done anything electrical and I would see why coils would just fail. The bike only has about 10K miles on it. I dont have a meter or anything to check electical stuff.... I am wondering if it is a plugged fuel tank vent but I dont have a hose attached so how do you blow that line out from the tank. Possibly stuffed up after being painted??? Use a long peice of 16/18 gauge wire, shove it up in there, or if your brave a cloth hanger, I dont think there is anything up there that can get damaged ? Quote Link to comment Share on other sites More sharing options...
cbrbear Posted June 16, 2008 Author Share Posted June 16, 2008 I will have to play around. I shouldnt have done soo many things at the same time. Makes it hard to figure out what is what. Though if it were the vent line then it should fix it by removing the gas cap or when the tank was removed the bike should run ok with just the gas in the carbs for a few until it runs out so I seriously doubt it is the vent line. As far as coils go I have never seen them half ass work, always just completely die... Quote Link to comment Share on other sites More sharing options...
CxBXR Posted June 16, 2008 Share Posted June 16, 2008 Here is a few of things I would do in your shoes: Dissamble the petcock & triple check it & flow test it. Pull plug, make sure it is jumping 1-3 inch gap (strong) Recheck plugs make sure they arent fouled from excess fuel Check all vaccum lines via the manual , & reinstall the air proportional valve or reed valves just to eliminate as a possiblility Last but not least: Borrow someones CDI box & swap with yours to eliminate possibility If the above did not cure anything I would be taking it in, for further diagnoses. Quote Link to comment Share on other sites More sharing options...
cbrbear Posted June 16, 2008 Author Share Posted June 16, 2008 Here is a few of things I would do in your shoes: Dissamble the petcock & triple check it & flow test it. Pull plug, make sure it is jumping 1-3 inch gap (strong) Recheck plugs make sure they arent fouled from excess fuel Check all vaccum lines via the manual , & reinstall the air proportional valve or reed valves just to eliminate as a possiblility Last but not least: Borrow someones CDI box & swap with yours to eliminate possibility If the above did not cure anything I would be taking it in, for further diagnoses. Its definately not the petcock as I have tested it on the bottle and it does the same thing. Plugs could be an issue but they are new iridium plugs (thought they have sat for 15 months but I dont think that is an issue) only vacuum lines on the bike are the one to the petcock valve and the one from the tpo system which is plugged as per directions I thought about re installing the pair system but I just dont see how that could have an effect this dramatic unless it wasnt sealed right and even then thats just a breathing system not really anything that would affect performance The CDI issue I talked with dyna about and they pretty much said uh dont sound like a coil or cdi issue at all.... so tomorrow painfully its going in the shop. Quote Link to comment Share on other sites More sharing options...
cbrxxquad Posted June 16, 2008 Share Posted June 16, 2008 two things, make sure the correct wire is on the positive side of the coil. Easy to get wrong Make sure you have the correct plug wire to the correct plug. left coil is for one and four check the main ground for clean and tight at the frame. New fuel? disconnect the fuel line from the carbs, and put in a bucket. pull a vacumn on the vacumn line and see the flow stays going. Something in the tank pluging the line,,,,rag...etc. to make power you have to get a flow of gas at a rate. will look the same. you can just suck on the vacumn line. if it flows good, then make sure the vacumn is not going away due to a crack in the lines. mightey vac is cheap and will show how much and provide it for you as well. First i have seen this so just quick answers, will think about it some more. Quote Link to comment Share on other sites More sharing options...
JasonW Posted June 17, 2008 Share Posted June 17, 2008 I know you said that it's definitely not the petcock, and not to insult your intelligence, but did you make sure that the vacuum hose was hooked up to the right nipple? I know it seems simple, but many have mistook the nipple at the far bottom of the petcock as the vacuum when it isn't anything at all. Also, are you running the bike with the lower fairings off? This too will cause it to run like shit. Just trying to think of things that haven't been mentioned. I'll keep thinking. Quote Link to comment Share on other sites More sharing options...
rideonXX Posted June 17, 2008 Share Posted June 17, 2008 Another thing that you could check that I had problem with-------a fellow helped tighten the clamps on the intake hoses and the pressure was enough to distort the carbs just enough that the sliders couldn't slide correctly. As I was trouble shooting I took it apart noticing how tight the 2 that he did were----redid them and all was well. Those on the intake side do not need to be tight. Wishing you the best---happy trails kel Quote Link to comment Share on other sites More sharing options...
CxBXR Posted June 17, 2008 Share Posted June 17, 2008 Update ? Did you take it in ? Quote Link to comment Share on other sites More sharing options...
cbrbear Posted June 17, 2008 Author Share Posted June 17, 2008 I took everyones advice and to no avail it still ran EXACTLY the same. So she is in the shop today for diagnostics and then once repaired dyno tuning.... FNA.... ugh.... Quote Link to comment Share on other sites More sharing options...
MR. WOMO Posted June 17, 2008 Share Posted June 17, 2008 I didn't notice it you mentioned what year Bird this was, but I have a '98, and after moving cross-country, in and out of a rental home, and finally our current house - I had a lot of bike "down-time". When I finally got some time with it running again last summer, it ran just as you're describing, really lousy one day, pretty decent another, and back again. I used a few tankfuls of Seafoam, and slowly but surely it began to come back to it's old self. I don't know if the carbs, etc. were jus kind of mucked up and that's what it took over a bit of time to clear 'em out, but I had the same concerns as you do (new plugs, tightened everything down - stuff that SHOULD have corrected the problem). Perhaps if possible, try and just run it for a few days/week with some Seafoam in the fuel mix and see if it goes away? Sorryif I got this to you a little late, but I hadn't seen the thread till now! Cheers, Kevin Quote Link to comment Share on other sites More sharing options...
cbrbear Posted June 17, 2008 Author Share Posted June 17, 2008 Thanks for the advice but I cleaned the carbs and went through them. Shop still after working all day dont have it running right. Jetting was WAAAAYYYY off... apparently it was running lean way lean in all areas so the main jet is now a 155 maybe more... but they are working on it. I may need a set of stock springs for the slides as the guy I got it from had a dyno jet jet kit. But base run without fixing anything it only put down 134 hp but was breaking up all ranges. So hopefully tomorrow as long as they can dial it in without the stock springs it should be good to go. She should put down some good HP as the bike is already begging for larger jets than any of the other systems they have dyno'd for 97-98 birds even with full ti systems! Quote Link to comment Share on other sites More sharing options...
CxBXR Posted June 18, 2008 Share Posted June 18, 2008 Good to hear, hope you break 150 Quote Link to comment Share on other sites More sharing options...
jon haney Posted June 18, 2008 Share Posted June 18, 2008 Thanks for the advice but I cleaned the carbs and went through them. Shop still after working all day dont have it running right. Jetting was WAAAAYYYY off... apparently it was running lean way lean in all areas so the main jet is now a 155 maybe more... but they are working on it. I may need a set of stock springs for the slides as the guy I got it from had a dyno jet jet kit. But base run without fixing anything it only put down 134 hp but was breaking up all ranges. So hopefully tomorrow as long as they can dial it in without the stock springs it should be good to go. She should put down some good HP as the bike is already begging for larger jets than any of the other systems they have dyno'd for 97-98 birds even with full ti systems! See post by RideonXX. That would explain the need for bigger jets. Also, Dynojet numbers their jets differtly than Mikuni or Kehin. Dynojet's 142 probably flows as much as the 155 they put in. I still think you're sucking air from somewhere. Have you taken the tops off of the carbs to make sure the slide diaphragms are installed properly and/or moving freely? Quote Link to comment Share on other sites More sharing options...
cbrbear Posted June 18, 2008 Author Share Posted June 18, 2008 Thanks for the advice but I cleaned the carbs and went through them. Shop still after working all day dont have it running right. Jetting was WAAAAYYYY off... apparently it was running lean way lean in all areas so the main jet is now a 155 maybe more... but they are working on it. I may need a set of stock springs for the slides as the guy I got it from had a dyno jet jet kit. But base run without fixing anything it only put down 134 hp but was breaking up all ranges. So hopefully tomorrow as long as they can dial it in without the stock springs it should be good to go. She should put down some good HP as the bike is already begging for larger jets than any of the other systems they have dyno'd for 97-98 birds even with full ti systems! See post by RideonXX. That would explain the need for bigger jets. Also, Dynojet numbers their jets differtly than Mikuni or Kehin. Dynojet's 142 probably flows as much as the 155 they put in. I still think you're sucking air from somewhere. Have you taken the tops off of the carbs to make sure the slide diaphragms are installed properly and/or moving freely? I dont run dyno jet jets. I am not sucking in air anywhere that was the first thing that was checked out. The slides are good and installed properly and moving freely. Also didnt find the post by RideonXX that you were talking a bout.. Quote Link to comment Share on other sites More sharing options...
cbrbear Posted June 18, 2008 Author Share Posted June 18, 2008 I know you said that it's definitely not the petcock, and not to insult your intelligence, but did you make sure that the vacuum hose was hooked up to the right nipple? I know it seems simple, but many have mistook the nipple at the far bottom of the petcock as the vacuum when it isn't anything at all. Also, are you running the bike with the lower fairings off? This too will cause it to run like shit. Just trying to think of things that haven't been mentioned. I'll keep thinking. Umm I am running the bike with no fairings... how does this cause it to run like shit? Quote Link to comment Share on other sites More sharing options...
TFT Posted June 18, 2008 Share Posted June 18, 2008 A few years ago a guy up here had a similar problem. He had taken the carbs apart to rejet and then had similar problem. It turned out that one of the diaphragms had a small hole. Somehow he punctured / tore it. Quote Link to comment Share on other sites More sharing options...
CxBXR Posted June 18, 2008 Share Posted June 18, 2008 Umm I am running the bike with no fairings... how does this cause it to run like shit? It really should not affect anything, worst case scenario is it might run a tad bit lean due to the increased fresh air flow, but would not affect it on a drastic level. A few years ago a guy up here had a similar problem. He had taken the carbs apart to rejet and then had similar problem. It turned out that one of the diaphragms had a small hole. Somehow he punctured / tore it. They are not easily torn, but easily punctured, even easier than that is not getting the diaphram seated properly around the carb lid. Quote Link to comment Share on other sites More sharing options...
JasonW Posted June 19, 2008 Share Posted June 19, 2008 Umm I am running the bike with no fairings... how does this cause it to run like shit? Sorry, that was a brain fart. The lowers won't affect it at all, but the upper apparently will. While I've never done it myself, I've seen more than a few people on here and the "other" sites have trouble running without fairings on the carbed bikes, either due to going the streetfighter route, or running it without the fairings after a wreck or after rejetting and testing before complete reassembly. It has to do with where the airbox takes in air, which is through those little vents in the sides of the upper. If the airbox is directly exposed to the airstream at speed it gets far too much air. Obviously this will only occur while under way, so it's tough to diagnose and it does apparently affect it on a drastic level. There is quite a bit of difference between those little slits in the fairing and having a snorkel directly out in the airstream. Just passing along what I've read here over the years as a possible culprit. I'm out of ideas. Quote Link to comment Share on other sites More sharing options...
cbrbear Posted June 19, 2008 Author Share Posted June 19, 2008 Umm I am running the bike with no fairings... how does this cause it to run like shit? Sorry, that was a brain fart. The lowers won't affect it at all, but the upper apparently will. While I've never done it myself, I've seen more than a few people on here and the "other" sites have trouble running without fairings on the carbed bikes, either due to going the streetfighter route, or running it without the fairings after a wreck or after rejetting and testing before complete reassembly. It has to do with where the airbox takes in air, which is through those little vents in the sides of the upper. If the airbox is directly exposed to the airstream at speed it gets far too much air. Obviously this will only occur while under way, so it's tough to diagnose and it does apparently affect it on a drastic level. There is quite a bit of difference between those little slits in the fairing and having a snorkel directly out in the airstream. Just passing along what I've read here over the years as a possible culprit. I'm out of ideas. Well apparently that is a majority of my problem. On the dyno the bike runs top but on the street the snorkles if you will on the air box become ram air and pressurizes the airbox and since the float bowls arent pressurized the bike basically starves for gas so apparently if you have a carbed bike and you dont block off direct air flow by using your inner cowls and such it will run like ass... so she put down 149 hp and 82ftlbs of torque and I am running 1 tooth down in front and up 1 tooth in the rear. Sucky thing is the dyno said my top speed was just over 160. I thought this bike stock did 186??? Yeah I know I am geared but come on.... Quote Link to comment Share on other sites More sharing options...
JasonW Posted June 19, 2008 Share Posted June 19, 2008 Umm I am running the bike with no fairings... how does this cause it to run like shit? Sorry, that was a brain fart. The lowers won't affect it at all, but the upper apparently will. While I've never done it myself, I've seen more than a few people on here and the "other" sites have trouble running without fairings on the carbed bikes, either due to going the streetfighter route, or running it without the fairings after a wreck or after rejetting and testing before complete reassembly. It has to do with where the airbox takes in air, which is through those little vents in the sides of the upper. If the airbox is directly exposed to the airstream at speed it gets far too much air. Obviously this will only occur while under way, so it's tough to diagnose and it does apparently affect it on a drastic level. There is quite a bit of difference between those little slits in the fairing and having a snorkel directly out in the airstream. Just passing along what I've read here over the years as a possible culprit. I'm out of ideas. Well apparently that is a majority of my problem. On the dyno the bike runs top but on the street the snorkles if you will on the air box become ram air and pressurizes the airbox and since the float bowls arent pressurized the bike basically starves for gas so apparently if you have a carbed bike and you dont block off direct air flow by using your inner cowls and such it will run like ass... so she put down 149 hp and 82ftlbs of torque and I am running 1 tooth down in front and up 1 tooth in the rear. Sucky thing is the dyno said my top speed was just over 160. I thought this bike stock did 186??? Yeah I know I am geared but come on.... Good, glad you found the problem. I found an old post that confirms this: http://www.cbr1100xx.org/forums/index.php?...ic=30294&hl, and I remember actually running into the same issue after my accident, but repaired the bike completely before realizing what was wrong. 160 sounds about right......stock bike w/ stock gearing struggles to hit 180 going downhill with a tailwind. Quote Link to comment Share on other sites More sharing options...
CxBXR Posted June 19, 2008 Share Posted June 19, 2008 so it's tough to diagnose and it does apparently affect it on a drastic level Alright, at least the problem was found, didnt realize the carbies were that sensitive. Quote Link to comment Share on other sites More sharing options...
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