SOHC.co.uk Forums > CB750
miss at 3.8K
billy192:
Strange but good day to day. went to do my test run and went about 12 miles to tescos with her in doors on the back and sur enough it starts spluttering at 4K. i was miffed to say the least.
when pulling away from lights i took it to 7K in each gear and boom no miss, the min i roll the throttle back comes the miss.
when she was getting a few things i took off the overflow pipes to each float bowl, not sure why but I am at the point of tiring anything.
on the way home a went on a little de tour. i went through maisemore to the M50 and down to a place called Newent which was 15 miles on the M50 and drove at a steady 60 -85 all the way down the M50.
brill. great runs sweet.
now i am going to go out with the tubes back on to see if it comes back.
Billy
not sure what difference these over flow pipes off make but hey its running goooooood
Green1:
Sounds a bit strange was one pipe pinched?
Mick
K2-K6:
I was wondering before you posted if you'd checked those overflow pipes, and as mick says they could be pinched at the bottom end of them.
As a point of interest they are named "overflow" pipes and we all now that with a sticking float/valve then the fuel of course comes out of them and helpfully drips onto the floor without covering the bike itself with petrol.
What they are not described as is a more critical function, they leave the float bowl at atmosheric pressure if they are clear. The difference between the vacuum in the carb throat and the status in the float bowl causes the fuel to be pulled into the engine at the rate dictated by the jet sizes, but if you artificially alter the the float bowl pressure then the change in difference between the two areas causes an unwanted change to the jetting calibration so the engine no longer runs as intended......happens if you change altitude as well, which is why carbs struggle to adapt.
Hopefully billy, you'll have got to the bottom of it.....tenacity rewarded i think, well done if it's definitely ok.
billy192:
i can blow through them but not freely as there are several zip ties. fingers crossed
Billy
Johnwebley:
--- Quote from: billy192 on July 07, 2014, 09:58:01 PM ---Strange but good day to day. went to do my test run and went about 12 miles to tescos with her in doors on the back and sur enough it starts spluttering at 4K. i was miffed to say the least.
when pulling away from lights i took it to 7K in each gear and boom no miss, the min i roll the throttle back comes the miss.
when she was getting a few things i took off the overflow pipes to each float bowl, not sure why but I am at the point of tiring anything.
on the way home a went on a little de tour. i went through maisemore to the M50 and down to a place called Newent which was 15 miles on the M50 and drove at a steady 60 -85 all the way down the M50.
brill. great runs sweet.
now i am going to go out with the tubes back on to see if it comes back.
Billy
not sure what difference these over flow pipes off make but hey its running goooooood
--- End quote ---
hope you have sorted it,I live close,and use those roads between Hereford,Newent,Glos,and Ledbury,
these are perfect for sohc s
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version