im having trouble with the air/fuel set up on me bike.
it wasnt set up right when I got it and I set about getting it running good again, any help appreciated heres the story so far.
The bike was bogging down in fifth and sixth,it was going up the gears ok but would just loose power and you would have to play with the throttle or drop a gear to get it rectified. It would always do it again and needles to say this got annoying so I got it on the dyno. this is the way the bike was set up going on the dyno.
#it had no fairings no clocks and renthal bars
#the main air duct was taped up
#all the smaller air tubes were gone
#dynojetted
#scorpian slip on end can
its not the prettiest but they are a class bike and id love to have it sorted.
anyway! put it on the dyno and found it had a max power of 76.65 so we took out the air filter and took the tape of the main air tube.
The result was an increase of power to 91.58.
we figured that the bike wasnt getting enough air.
The dyno also showed up a high air fuel reading between 6 and 7 thousand rpm.
The man at the shop said to even this out I would have to move the clip on the needles in the carbs down a notch.
I done this thinking it would sort it out.
How wrong was I !!!
The bike ran even worse bogging in third and fourth now.
I decided to block the main air box again and to my suprise the power delivery was better. It still wasnt anywhere near perfect but there was a noticable difference in riding it with the main air tube open.
I tought id run it past you guys first before I went operating again or spend loads of money.

my main worry at the moment is the set up of the air box as there are alot of pipes missing.
Ive heard of race bikes set up like this, can these bikes be run without the smaller lower speed air tubes.

so thats me problem with me f3
hope yis can help
thanks
peavey

 

No gauges? Well for one, the air solenoid isn't working. Its tied into the speedometer. Without the speedo working correctly (or even there), the solenoid will never switch from the low speed intakes to the ram duct.

Check and see if the solenoid was properly bypassed. https://cbrforum.com/forum/showpost....30&postcount=8

Put the clip back to its original position and give it a go.

 

I think that you're finding out how complex the air circuits are on these bikes. Spicymeowmix can speak directly about disconnected or removed hoses and the effects it has on performance. I see that you got a significant increase in power by removing the tape, but with that much of a change from totally blocked to unblocked it's hard to say what would have happened if you made more subtle changes.

Did you get a print out of your dyno run ? The photo is a little tough to see. Maybe a photo (larger) of the printout if you have it. The clips on the needles, were you supposed to lower the needle or lower the clips ? Lowering the clips is going to raise the initial starting point of the needle as well as increase the amount of fuel across the mid range. Lowering the needle has the opposite. Have the slides been drilled ? Have different springs been installed in the slides ? Have you changed jets ? If so, what size are you running ?

This additional information will help others here better understand, and possibly help.

 

kuroshio: that link was brilliant. there is no solenoid on the bike. the pipe coming from the carbs is not even hooked up to the ram air as described in the link. Its somewhere to start, thanks

IDODIRT: ill try and enlarge the dyno print out(its a computer thing). he definately said lower the clips.
slides are not drilled and springs are not changed
jets im not sure ! would these have been changed when the bike was dyno jetted?
Im going to start with sorting out the air ducts and work from there,

nice one boys thanks
peavey

 

You're not getting any air from the ram duct? That'll cause a flat spot definitely.

The bike can't snorkel enough air at higher speeds

 

Get the emulsion tubes back on the airbox.Put the air filter back in.Are there holes drilled in the airbox lid?

 

kjohnson: im on the scout for new air tubes,hopefully ill have some today. there are no holes drilled in the air box lid.

 

howdy yall,
just an update on progress
I bypassed the air solenoid valve correctly and took the bike for a rip.
Oh dear!!!
1st gear ok but when shifted into second she bogged down, same through the rest of the gears.
I then decided to tape up the main air snorkel and give er a go, to my suprise the bike went like a dream. ,up through all the gears and no power loss. Needless to say I was well happy with the results.
To me the bike is sorted now but im still a bit curious as to why it runs better with the ram air blocked off
im gona get it back on the dyno to see what its puttin out when I have some spare cash.
Otherwise she's rockin an rollin
thanks for the advise,
peavey

 

Usually an indication that the bike is running lean. Jet/carb issues?