I’m having a few issues keeping my 1984 VF1000 running…it has been off the road for the last 10 months whilst undergoing extensive aesthetic re-work in an aim for a street-fighter look and amongst other mods which are finally complete all is ready to go!!!
When it’s running, it’s running very well, idle is great, performance through the whole rev. range is awesome…then for no apparent reason it just “fluffs out” almost like there is a permanent flat spot or something similar…I could only really relate it to (in an attempt for anyone that could maybe help me diagnose the problem) my 1985 KX80 that had similar running problems and it was the stator failing(obviously slightly different bikes and running principles however that noise and flatness you get when you have no spark)!!!
I have changed the plugs, drained the carby bowls, changed fuel filter, tested fuel pump, freeze sprayed the coils at the time of rough running, checked coil parameters (resistances etc) checked H.T. leads for resistance, checked V.reg output, checked carby manifold boots for leaks and other things along the way…However when you let it cool all the way down and start it again all is good untill once again the same problem. Initially it happened as I opened up to about 7 grand and backed off…as soon as I backed off it “fluffed out”
Carby or spark???
Can anyone give me a few hints??? Any input or feedback would/will be greatly appreciated, Any other questions that may help with diagnosing are more than welcomed and as mentioned, greatly appreciated!!!
I’m having a few issues keeping my 1984 VF1000 running…it has been off the road for the last 10 months whilst undergoing extensive aesthetic re-work in an aim for a street-fighter look and amongst other mods which are finally complete all is ready to go!!!
When it’s running, it’s running very well, idle is great, performance through the whole rev. range is awesome…then for no apparent reason it just “fluffs out” almost like there is a permanent flat spot or something similar…I could only really relate it to (in an attempt for anyone that could maybe help me diagnose the problem) my 1985 KX80 that had similar running problems and it was the stator failing(obviously slightly different bikes and running principles however that noise and flatness you get when you have no spark)!!!
I have changed the plugs, drained the carby bowls, changed fuel filter, tested fuel pump, freeze sprayed the coils at the time of rough running, checked coil parameters (resistances etc) checked H.T. leads for resistance, checked V.reg output, checked carby manifold boots for leaks and other things along the way…However when you let it cool all the way down and start it again all is good untill once again the same problem. Initially it happened as I opened up to about 7 grand and backed off…as soon as I backed off it “fluffed out”
Carby or spark???
Can anyone give me a few hints??? Any input or feedback would/will be greatly appreciated, Any other questions that may help with diagnosing are more than welcomed and as mentioned, greatly appreciated!!!
Thanks in advance,
NSPYR
V4’s…Only wings could make them better!!!
Hello NSPYR…sorry to hear about your problem mate. You’ve checked everything I’d have thought to do. You may have a wait for an answer as it’s a bit slow on this forum.[|)] Someone will be along at some time…and if bif gets his head out of his arse agin it may be sooner rather than later.[:D] Be patient mate. I’ll be interested in the solution when you get it.
Hi there NSPYR,
Just a question that may help,does the tacho drop off to zero when this happens?
Its just that the Interceptor boys mention a simular thing when one of the ignition units starts to fail.Only one unit drives the tacho so if its failing you loose the rev counter. Also worth checking the multi plug connectors to the loom I have found that these can corrode and give odd symptoms too.
Keep us all posted as to progress regards BIF
Thanks for your reply…I guess patience has been instilled in me since starting this project [:D] and hopefully I get some feedback in due course…as for letting you know when it’s finally figured out, no problem!!! The more we all know the less we dont!!!
I’m having a few issues keeping my 1984 VF1000 running…it has been off the road for the last 10 months whilst undergoing extensive aesthetic re-work in an aim for a street-fighter look and amongst other mods which are finally complete all is ready to go!!!
When it’s running, it’s running very well, idle is great, performance through the whole rev. range is awesome…then for no apparent reason it just “fluffs out” almost like there is a permanent flat spot or something similar…I could only really relate it to (in an attempt for anyone that could maybe help me diagnose the problem) my 1985 KX80 that had similar running problems and it was the stator failing(obviously slightly different bikes and running principles however that noise and flatness you get when you have no spark)!!!
I have changed the plugs, drained the carby bowls, changed fuel filter, tested fuel pump, freeze sprayed the coils at the time of rough running, checked coil parameters (resistances etc) checked H.T. leads for resistance, checked V.reg output, checked carby manifold boots for leaks and other things along the way…However when you let it cool all the way down and start it again all is good untill once again the same problem. Initially it happened as I opened up to about 7 grand and backed off…as soon as I backed off it “fluffed out”
Carby or spark???
Can anyone give me a few hints??? Any input or feedback would/will be greatly appreciated, Any other questions that may help with diagnosing are more than welcomed and as mentioned, greatly appreciated!!!
Hi NSPYR
Have you removed the air horns off the front off the standard air filter box in the miss conception that it will breath better , VF,s will flat spot and plato in power unless you rejet the carbys , easier to just refit the horns ,
Hope this helps
Gidday. My VF1000F2 had much the same problem. Went thru the same process ie carbys, plugs etc.Check that your fuel pump is working by powering it straight from the battery as a test. Fuel filter behind coolant reservoir might be blocked. Do the carbys run dry when it fluffs out? If the pulse generator coils inside the clutch cover are faulty two cylinders will cut out, when this happens the fuel pump is automatically cut to avoid engine damage resulting from running on two cylinders( this turned out to be the problem with my bike) Depending on the model the spark control units under the seat above the taillight might be at fault also. The 1985 models only have one large unit instead of two.Could also be fuel pump relay located near voltage rectifier under lh side cover. Hope some of this helps.