erixx Posted September 22, 2006 Share Posted September 22, 2006 Hi! after reading ev erything in this forums, without finding exactly the same scenary, i need to ask you for help, mainly because my shop has given me a date.. next month! Description: - The engine is nearly running fine at startup and during city or mountain riding. -But as soon as I once open the throttle fully and go into warp speed (over 100 mph) the engine starts to cough, to rattle, losing power, consuming more petrol also. It clearly sounds as if only one or two cylinders are exploding properly. - Sometimes a quick full throttle clears it for a short time, most part of the time, after this starts, the throtlle doesn't do anything anymore, i can open it, nothing happens. - If i ride cautiously with low throtle i can keep on riding, and bring it home. - After this symptom occurs, the bike won't go back to normal and good running, even if I return to city riding. - But.... when the engine has been off for about 30 minutes, everything is fine until I go fast again... I know i should start checking the plugs, but i can't manage to take the air box fully off. Sometimes it looks like fuel problems, sometimes electrical, sometimes air box or valve problems... i'm so confused by the syntoms! I have had fuel or electircal problems with other bikes and the problem was so obvious to me, but i just can't understand why at high speed i got problems, but not at aggressive mountain riding.... :icon_wall: Thanks in advance oh sages of the XX!!!! :icon_clap: Quote Link to comment Share on other sites More sharing options...
airborneXX Posted September 22, 2006 Share Posted September 22, 2006 What is stopping you from removing the airbox? I'm thinking the carbs. need a good cleaning. Maybe the main jest are clogging or the needle isn't rising properly due to a sticking slide or bad diaphragm. Of course since you're that far into the bike already you might as well throw in a set of plugs. Also are you running a stock air filter or a K&N? Is the filter clean? Quote Link to comment Share on other sites More sharing options...
erixx Posted September 22, 2006 Author Share Posted September 22, 2006 Thanks for the response Airborne! For sure, i should have go ahead with removing parts... maybe tomorrow saturday. My air filter is clean and i have never had spark plugs problems, but who knows! I will try to clean the carbs and check the plugs... Thansk again, and if somebody knows this problem description, it would be great to hear from you! :icon_clap: Quote Link to comment Share on other sites More sharing options...
beondwacko Posted September 23, 2006 Share Posted September 23, 2006 It sounds like a venturi slide is hanging up and dumping fuel onyl afer the throttles are pinned for a few moments. Was the bike ever sitting for any decent amount of time? It sounds as if the carbs need a professional going through, not just a quick looksie. Quote Link to comment Share on other sites More sharing options...
airborneXX Posted September 23, 2006 Share Posted September 23, 2006 No problem. Post your findings and feel free to ask questions And ask them soon I just had my carbs off for cleanng tonight. Details don't stay in my head like they use to :icon_duh: Quote Link to comment Share on other sites More sharing options...
Motor Psycho Posted September 23, 2006 Share Posted September 23, 2006 Check to see if the fuel tank isn't venting by opening the cap and see if that helps. Quote Link to comment Share on other sites More sharing options...
erixx Posted September 25, 2006 Author Share Posted September 25, 2006 thanks all, but still no go. The bike has not been standing still ever. There was a 'screwed' screw in the airbox top (plasic) letting air pressure out i fixed that, thinking that was the problem, test ride, still a problem. Today she's going to the shop... will tell... OMG... Quote Link to comment Share on other sites More sharing options...
Pete in PA Posted September 25, 2006 Share Posted September 25, 2006 Sounds like the fuel petcock diaphram to me. Quote Link to comment Share on other sites More sharing options...
erixx Posted September 26, 2006 Author Share Posted September 26, 2006 Sounds like the fuel petcock diaphram to me. Thanks, but how can only high speed cause the problem if its the diaphragm? :icon_think: Quote Link to comment Share on other sites More sharing options...
bartonmd Posted September 26, 2006 Share Posted September 26, 2006 Sounds like the fuel petcock diaphram to me. Thanks, but how can only high speed cause the problem if its the diaphragm? :icon_think: Actually, I had this EXACT same problem (only at slightly lower speeds) with my '83 shadow... The petcock was plugged up, and it would flow enough fuel for just running around, but if I'd get on the highway for more than a mile or so, it would lean out and cut out like you're describing... Is the petcock all the way in the "on" position? If it's not, that could be your hangup right there... or, you've got a vacuum diaphram that can't open the fuel flow enough to get enough fuel to the engine... I'd start in the fuel petcock... of course, this is as long as you've already tried doing it with the gas tank open... Put your spare key in the gas cap and don't open it... ride the thing until it starts fucking up on you, and when it does, pop open the gas cap, and if it starts running right very soon after that, you've got a plugged up tank vent... Mike Quote Link to comment Share on other sites More sharing options...
Pete in PA Posted September 27, 2006 Share Posted September 27, 2006 Sounds like the fuel petcock diaphram to me. Thanks, but how can only high speed cause the problem if its the diaphragm? :icon_think: Ar high speeds/rpm you demand more fuel flow and it exceeds what's flowing throught the petcock. It's just 4 little screws and it will be revealed. I and several here had folded/wrinkled/cut diaphragms from the factory. Quote Link to comment Share on other sites More sharing options...
erixx Posted September 28, 2006 Author Share Posted September 28, 2006 hi guys, i'm still not able to give any conclusions, but i will ASAP!! Thanks a lot in the meanwhile! :icon_clap: Quote Link to comment Share on other sites More sharing options...
erixx Posted December 4, 2006 Author Share Posted December 4, 2006 Hi again!!! i have not writen any news in this thread becasue there was no news! My shop told me to wait until the parts arrived, but then some parts were still not there. He ordered the accelerator sensor (my Bird is the Carb'ed) and 4 rubber rings that fix the carbs to the cilinders (theses came after 1 extra month! ....) The sensor and some rings needed replacement, were replaced, the bike given to me... BUT still the same problem... My mechanic told me cylinders 2 and 3 have lost compression, but IMHO that can't be the cause of this frustation. I have riden the bike since, before returning it to the shop... The horrible engine sound and nearly ABSOLUTLY loss of power, always occurs after fast acceleration up to high speed in minimum time (if i do not accelerate hard i can ride all day without any problem) Also, when this problem occurs, if I stop 15 minutes the bike is ok again, and i can accelerate all i want in neutral and it doesn't occur. Voltages, amps were checked, air intakes where checked... My mechanic is a bit lost, and so am I. Might be the R1 regulator? Some membrane in the carbs? Only occurs when fast riding on the highway, never in city or canyons.. WHAT CAN THIS BE? HEEEEEEEELP... I love my bike and for the first time in 6 years i'm thinking about selling it.... horror! Quote Link to comment Share on other sites More sharing options...
airborneXX Posted December 4, 2006 Share Posted December 4, 2006 Did he replace the plugs and clean the carbs? How many miles are on the engine? I find it hard to believe you have low compression in 2 cylinders. Quote Link to comment Share on other sites More sharing options...
kiwimack Posted December 4, 2006 Share Posted December 4, 2006 is this a reliable shop you go to? still would look at the petcock, take it apart you got nothing to lose check out the diaphram.... how much has the shop cost you so far? Quote Link to comment Share on other sites More sharing options...
mikesail Posted December 4, 2006 Share Posted December 4, 2006 Hi again!!! i have not writen any news in this thread becasue there was no news! My shop told me to wait until the parts arrived, but then some parts were still not there. He ordered the accelerator sensor (my Bird is the Carb'ed) and 4 rubber rings that fix the carbs to the cilinders (theses came after 1 extra month! ....) The sensor and some rings needed replacement, were replaced, the bike given to me... BUT still the same problem... My mechanic told me cylinders 2 and 3 have lost compression, but IMHO that can't be the cause of this frustation. I have riden the bike since, before returning it to the shop... The horrible engine sound and nearly ABSOLUTLY loss of power, always occurs after fast acceleration up to high speed in minimum time (if i do not accelerate hard i can ride all day without any problem) Also, when this problem occurs, if I stop 15 minutes the bike is ok again, and i can accelerate all i want in neutral and it doesn't occur. Voltages, amps were checked, air intakes where checked... My mechanic is a bit lost, and so am I. Might be the R1 regulator? Some membrane in the carbs? Only occurs when fast riding on the highway, never in city or canyons.. WHAT CAN THIS BE? HEEEEEEEELP... I love my bike and for the first time in 6 years i'm thinking about selling it.... horror! your mechanic is probably an idiot. The regulator does not know or care what power the engine is putting out. Air intakes don't change after a high speed run. What you describe is the classic problem of fuel starvation. The carb mounting rings would only affect the idle and low power level mixture. the earlier suggestion of checking the petcock is good advice. Also check the fuel filter. I suggest you pull off the fuel supply line and verify it will supply a good flow into a can. you can suck on the vacuum petcock control hose to turn on the flow. It should flow pretty freely. If it is the carbs it would most likely affect only one, although it would cause a dramatic change. Quote Link to comment Share on other sites More sharing options...
kiwimack Posted December 4, 2006 Share Posted December 4, 2006 Hi again!!! i have not writen any news in this thread becasue there was no news! My shop told me to wait until the parts arrived, but then some parts were still not there. He ordered the accelerator sensor (my Bird is the Carb'ed) and 4 rubber rings that fix the carbs to the cilinders (theses came after 1 extra month! ....) The sensor and some rings needed replacement, were replaced, the bike given to me... BUT still the same problem... My mechanic told me cylinders 2 and 3 have lost compression, but IMHO that can't be the cause of this frustation. I have riden the bike since, before returning it to the shop... The horrible engine sound and nearly ABSOLUTLY loss of power, always occurs after fast acceleration up to high speed in minimum time (if i do not accelerate hard i can ride all day without any problem) Also, when this problem occurs, if I stop 15 minutes the bike is ok again, and i can accelerate all i want in neutral and it doesn't occur. Voltages, amps were checked, air intakes where checked... My mechanic is a bit lost, and so am I. Might be the R1 regulator? Some membrane in the carbs? Only occurs when fast riding on the highway, never in city or canyons.. WHAT CAN THIS BE? HEEEEEEEELP... I love my bike and for the first time in 6 years i'm thinking about selling it.... horror! you gotta keep the faith my blackbird riding brother, there is not a lot that goes wrong with these that can't be fixed by you short of blowing an engine ( thats like getting teeth from a hen) or crashing it you can take care of your baby........ Quote Link to comment Share on other sites More sharing options...
erixx Posted December 4, 2006 Author Share Posted December 4, 2006 Thanks for the fast reactions, my brothers! Definately i will tell the mech to look at the diafragms (those weird things lol) and fuel lines. He isn't a bad mech, but has opened a new shop and is very busy lately, he was the XX specialist here in the past and always been up to the task. My Bird has 140.000 km behind, a friend of mine with 150.000 km on his bird also fitted new ...err... pistons... I really don't harm my bike when cold or anytime, but i have done lots of trackdays... must be that. Next week he will fix it or fix it! Quote Link to comment Share on other sites More sharing options...
bartonmd Posted December 4, 2006 Share Posted December 4, 2006 Thanks for the fast reactions, my brothers! Definately i will tell the mech to look at the diafragms (those weird things lol) and fuel lines. He isn't a bad mech, but has opened a new shop and is very busy lately, he was the XX specialist here in the past and always been up to the task. My Bird has 140.000 km behind, a friend of mine with 150.000 km on his bird also fitted new ...err... pistons... I really don't harm my bike when cold or anytime, but i have done lots of trackdays... must be that. Next week he will fix it or fix it! after seeing what I've typed a few months ago, it appears that I missed something in your original post... You said it sounds like it's missing on one or 2, and consuming MORE fuel, and sometimes goes away if you pin the throttle... I missed that before... I had the same thing happen on my 'bird right after I put the jet kit in... it ended up being one of the slides getting stuck open when I went WOT. Sometimes it cleared OK if I went WOT to redline again (effectively lifting the slide off of what it was resting on), and sometimes that wouldn't clear it... From what you're saying about it going away when you let it sit engine off, I wonder if you might have a broken spring that pushes the slide down, or if someone put a jet kit in, I wonder if they forgot to put one of the springs again... I'd remove your air box (VERY simple job) and lift up the slides with your fingers and see that they come back down by themselves, with force, but not so quickly... FWIW, it has nothing to do with cylinder compression, rubber cylinder rings, or anything electrical... (although if I'm right, and the slides are sticking open, and it's been ridden much in that condition, it could be that all the extra fuel has "washed" the cylinder walls of the lubrication, and has caused some scoring between the rings and cylinder bore, but that would be a product of the running probem, not a cause of it) Mike Quote Link to comment Share on other sites More sharing options...
INDYERIKXX Posted December 4, 2006 Share Posted December 4, 2006 Thanks for the fast reactions, my brothers! Definately i will tell the mech to look at the diafragms (those weird things lol) and fuel lines. He isn't a bad mech, but has opened a new shop and is very busy lately, he was the XX specialist here in the past and always been up to the task. My Bird has 140.000 km behind, a friend of mine with 150.000 km on his bird also fitted new ...err... pistons... I really don't harm my bike when cold or anytime, but i have done lots of trackdays... must be that. Next week he will fix it or fix it! after seeing what I've typed a few months ago, it appears that I missed something in your original post... You said it sounds like it's missing on one or 2, and consuming MORE fuel, and sometimes goes away if you pin the throttle... I missed that before... I had the same thing happen on my 'bird right after I put the jet kit in... it ended up being one of the slides getting stuck open when I went WOT. Sometimes it cleared OK if I went WOT to redline again (effectively lifting the slide off of what it was resting on), and sometimes that wouldn't clear it... From what you're saying about it going away when you let it sit engine off, I wonder if you might have a broken spring that pushes the slide down, or if someone put a jet kit in, I wonder if they forgot to put one of the springs again... I'd remove your air box (VERY simple job) and lift up the slides with your fingers and see that they come back down by themselves, with force, but not so quickly... FWIW, it has nothing to do with cylinder compression, rubber cylinder rings, or anything electrical... (although if I'm right, and the slides are sticking open, and it's been ridden much in that condition, it could be that all the extra fuel has "washed" the cylinder walls of the lubrication, and has caused some scoring between the rings and cylinder bore, but that would be a product of the running probem, not a cause of it) Mike + 1 on the slides i would look @ that also! Erik Quote Link to comment Share on other sites More sharing options...
Eric_The_Jew Posted December 4, 2006 Share Posted December 4, 2006 Yup, have the carbs completely gone through. As the others have stated, it could definitely be a sticky slide. It probably wouldn't hurt (with your mileage) to have the emulsion tubes replaced while you're in there. They've been known to wear out with high mileage and throw your air fuel mixture all out of whack. Quote Link to comment Share on other sites More sharing options...
erixx Posted January 14, 2007 Author Share Posted January 14, 2007 SOLVED! A shame i did not take a pic... On the side of the carburators where the position sensor is, there was a invisible crack (sp?), that only was discovered after desasembling the thing a second time, cleaning it again and using a special product (it stinks). It was rebuild and now the bike is fine! Everything else is fine (they inspectioned every bloddy thing!) I wonder if anybody ever suffered this... Thanks for the support! Quote Link to comment Share on other sites More sharing options...
bartonmd Posted January 14, 2007 Share Posted January 14, 2007 SOLVED! A shame i did not take a pic... On the side of the carburators where the position sensor is, there was a invisible crack (sp?), that only was discovered after desasembling the thing a second time, cleaning it again and using a special product (it stinks). It was rebuild and now the bike is fine! Everything else is fine (they inspectioned every bloddy thing!) I wonder if anybody ever suffered this... Thanks for the support! Congratts! So where, exactly, was what cracked? Was it the carb boot cracked? the carb body? The TPS? the engine block? what? Mike Quote Link to comment Share on other sites More sharing options...
erixx Posted January 15, 2007 Author Share Posted January 15, 2007 hi, it started at the base of the TPS (where it is screwed to the carbs), and was 2 cm long. Not visible if its cold. Must have had a terrific effect on the inside pressure and air/gas mix! thanks again for all the support! I have beers waiting for all of you here in Valencia! Quote Link to comment Share on other sites More sharing options...
bartonmd Posted January 15, 2007 Share Posted January 15, 2007 hi, it started at the base of the TPS (where it is screwed to the carbs), and was 2 cm long. Not visible if its cold. Must have had a terrific effect on the inside pressure and air/gas mix! thanks again for all the support! I have beers waiting for all of you here in Valencia! OK, so the TPS was cracked, or the carb was cracked at the base of the TPS? Mike Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.