RPM not going back down

[LeBouc]

kebabs: The only problem I had when I decided to open the carbs was starting when the engine was cold. It would start with only one cylinder (the left) until the revs would reach 2,500; then the second one would come in and after 30 secs, it would idle perfectly. Other than that, it was working as good as it could. I thought that it would be the idle circuit so I played with it. What I see now is that it's easy to start, has a good idle (a little too low to my taste) but the engine does not drop back fast enough when I let the throttle so when I change gear up, the rev have not fallen enough and I end up with the equivalent of power shift. If I shift down, the rear wheel stops turning for a little while. That's not safe and it was not acting like that before. I don't like either that when I play with the pilot screw (the one at the top of the outlet throat of the carb) of the right cylinder, the revs don't change at all while I can adjust the left one without problem. I will recheck the valve adjustments and the timing because all jets and passages have been checked and overcleaned and rechecked!

 

[kebabs]

kebabs: The only problem I had when I decided to open the carbs was starting when the engine was cold. It would start with only one cylinder (the left) until the revs would reach 2,500; then the second one would come in and after 30 secs, it would idle perfectly. Other than that, it was working as good as it could. I thought that it would be the idle circuit so I played with it. What I see now is that it's easy to start, has a good idle (a little too low to my taste) but the engine does not drop back fast enough when I let the throttle so when I change gear up, the rev have not fallen enough and I end up with the equivalent of power shift. If I shift down, the rear wheel stops turning for a little while. That's not safe and it was not acting like that before. I don't like either that when I play with the pilot screw (the one at the top of the outlet throat of the carb) of the right cylinder, the revs don't change at all while I can adjust the left one without problem. I will recheck the valve adjustments and the timing because all jets and passages have been checked and overcleaned and rechecked!

ok fair enough.check the timing and valve clearance. if the revs are hanging up I'd say you have a mixture issue fuel screws not set right. have the carbs been balanced I used a kit called carbtune to balance mine and what a difference it made .

 

[kebabs]

ok fair enough.check the timing and valve clearance. if the revs are hanging up I'd say you have a mixture issue fuel screws not set right. have the carbs been balanced I used a kit called carbtune to balance mine and what a difference it made .

I also ment to say all those symptoms your having.i had them.only one cylinder firing, one side running hotter than the other I never touched valve clearance, timing or points.

 

[LeBouc]

ok fair enough.check the timing and valve clearance. if the revs are hanging up I'd say you have a mixture issue fuel screws not set right. have the carbs been balanced I used a kit called carbtune to balance mine and what a difference it made .

I have visually balanced them but I will check with my vacuum testers which might give me interesting infos. Also, I want to swap the air filters to see if it makes a difference...

 

[kebabs]

I have visually balanced them but I will check with my vacuum testers which might give me interesting infos. Also, I want to swap the air filters to see if it makes a difference...

I visually did mine and couldn't believe how far I was out.is it pod air filters

 

[LeBouc]

I visually did mine and couldn't believe how far I was out.is it pod air filters

Original air filters

 

[kebabs]

Original air filters

ok suppose you could change these to see how it goes.theyll be lots of trial and error with some head scratching to

 

[LeBouc]

yes mine are the metal floats have you checked the fuel mixture screws are the tips of them ok
are your coils ok
I had a idle problem when engine was hot it would cut out at traffic lights etc.i always thought it was the carbs .I changed the coils it now idles perfect when hot.the coils on my bike were 43 years old and needed changing.

Somebody (I can't find who!) told me to balance my carbs, that it would make a huge difference. I did. And the effect is humonguous! This bike has never felt like that before. It accelerate much more strongly, even in 6th at 3500rpm! No more problem of the rpm not gong back fast enough and this has also reduced 10 times the vibrations. With the anti vibration device that I had built for it, I barely feel the vibrations! I will still have some very small issues to take care of but I am so happy. So a MAXI thanks to the guy who suggested to me to balance the carbs (totally unbalanced which caused one to work overtime when I was letting the throttle!)

Ah, ah! It was you! So thanks a million man!

 

[kebabs]

Somebody (I can't find who!) told me to balance my carbs, that it would make a huge difference. I did. And the effect is humonguous! This bike has never felt like that before. It accelerate much more strongly, even in 6th at 3500rpm! No more problem of the rpm not gong back fast enough and this has also reduced 10 times the vibrations. With the anti vibration device that I had built for it, I barely feel the vibrations! I will still have some very small issues to take care of but I am so happy. So a MAXI thanks to the guy who suggested to me to balance the carbs (totally unbalanced which caused one to work overtime when I was letting the throttle!)

Ah, ah! It was you! So thanks a million man!

Great so all is good

 

[kebabs]

Great so all is good

you must tell me about the anti vibration device

 

[LeBouc]

you must tell me about the anti vibration device

Here is a copy of the drawing done with Google SketchUp (free); the black pieces are rubber seals that are expanded in the handlebar tube by the nut (the white end round piece - plastic) and bolt (steel) that squeeze them when tightening so that the assembly stays inside the bar. The bolt goes through all the parts to screw in the special nut at the end. The spacers (steel) are outside of the handlebar as well as the hex part of the middle white piece (plastic) (the hex is there to prevent the end special nut from turning while the bolt screws in. The 3 yellowish parts (plastic) are there to compress the rubber seals and are slipped over the 2 white parts. I show only 3 spacers but you can add as much as you need to compensate for the type of vibration that you want to cancel; more weight will cancell lower speed vibes. I have 10 on my bike (each side of the handlebar). I would have added the .skp file and the .dae for 3D printing but they are not supported for adding with the message. Hope it's clear!

 

[LeBouc]

Great so all is good

Almost. I have some pops when I close the throttle but I believe that it will be easy now to prevent them since the pilot screw is only 1 1/2 turn out!

 

[kebabs]

Almost. I have some pops when I close the throttle but I believe that it will be easy now to prevent them since the pilot screw is only 1 1/2 turn

 

[kebabs]

thats great that you got there. I'll look into these antivibration things. didn't know there was such a thing. I could do with getting rid of some of the vibes on my bike

 

[kebabs]

thats great that you got there. I'll look into these antivibration things. didn't know there was such a thing. I could do with getting rid of some of the vibes on my bike

I have bar end mirrors .dont think I could fit them.

 

[kebabs]

I have bar end mirrors .dont think I could fit them.

ment to say .If you have a slight pop on decel that's OK.but if it's annoying you try turning the fuel screws out about one eighth of a turn

 

[LeBouc]

ment to say .If you have a slight pop on decel that's OK.but if it's annoying you try turning the fuel screws out about one eighth of a turn

That's what I thought!

 

[LeBouc]

I have bar end mirrors .dont think I could fit them.

I prefer to have my mirrors attached closer to the steering stem because the further you are from it, the more amplitude the vibrations will have, buzzing the image even more. But you could find a way to use the mirror stem to make it heavier to reduce the vibrations....

 

[tstidham]

tstidham, I checked and rechecked the passages and the jets and they are all free flowing. I can spray brake fluid and see it spaying out at the right place. The problem is not there. I thought that it could be caused by the rubber cap on the pilot jet inlet that would prevent fuel from entering so I removed them but that didn't change anything. I begin to think that it might be something else than the carbs.

Mine also sprayed cleaner out of everything on the first two cleanings, but I had very little rpm responses from adjusting the mixture screws. And the most common cause is a partial blockage or the tip of the screw broken in the carb. I was actually pretty surprised how much gunk pushed out of the one pilot jet when I ran the copper wire through it. It eye balled as being clear when peering through it at a light as well. Realize in cleaning, you're pressure spraying fluid through it vs relying on idle vacuum to pull fuel through it. Anyway, just a suggestion.

 

[kebabs]

I prefer to have my mirrors attached closer to the steering stem because the further you are from it, the more amplitude the vibrations will have, buzzing the image even more. But you could find a way to use the mirror stem to make it heavier to reduce the vibrations....

thanks for that I'll give it a bash