FCR's fitted some questions

[SDN]

Fitted the FCR's

1st try ran like a pig, hard to start would not rev out, tick over or run stable at mid throttle, belching out black smoke and bogging down

Oviously too rich - checked jets 158 fitted - needle 3rd from top

Fited 150 jets and took the clip up one ring

now bike ticks over OK, runs mid and full throttle but just of tick over bogs down - what should fuel scres be set at?

Also how are casrb ballanced, mine are out

[SDN]

Oh BTW I put the tank on and it runs a lot worse, so sound like it is rich as the tank will be restricting air flow to my way of thinking, at bottom end and will not tickover properly now.

[Mincehead]

Fitted the FCR's

1st try ran like a pig, hard to start would not rev out, tick over or run stable at mid throttle, belching out black smoke and bogging down

Oviously too rich - checked jets 158 fitted - needle 3rd from top

Fited 150 jets and took the clip up one ring

now bike ticks over OK, runs mid and full throttle but just of tick over bogs down - what should fuel scres be set at?

Also how are casrb ballanced, mine are out

Right, first things first.......................
Set BOTH flatslides with something of indentical thickness between them and the carb body, I use ground tool steel pins that I have. You`ll need to remove the carb tops and it`s not really straightforward in all honesty so if you`re not too good mechanically maybe time to ask someone else to assist you.
Then check BOTH floats are set to the same height too.
Next start with the mixture and air correction screws backed out maybe two turns as a base setting, run the bike without the tank on by leaving it in an UP position with extended hoses or even using a wee portable tank / bottle full of fuel.
I have vaccum guages (Morgan carbtunes) brilliant at getting carbs balanced but even by ear you can get them pretty good with practice.

[Dav]

FYI base settings are air 1.5 turns out, fuel 1 turn out, 150 main, floats 9mm and needle at the middle position. I'll be interested to see how you go, mine's weak off idle also.

[Con Rod]

Also how are casrb ballanced, mine are out

as an alternative to buying or borrowing vacuum gauges you can make a set very easily and cheaply.

[SDN]

I don't have any sort of manual for my carbs, for the low throttle circuit, is there a fuel and air screw, or or fuel screw and slow air jet?

From my quick look, I can only remember one adjustment screw, which comes through the bottom of the float bowl

I believe that screwing this in will make the 0 -1/8 throttle leaner?

If I am outside 1 - 2 turns out then conventional wisdom is that slow running jet is wrong - correct?

[Dav]

Bear in mind I don't know much but am learning The screw on the intake side next to the air jet is the air screw...shouyld be 1.5 turns out. The screw on the engine side (accessed thru the float bowl) is the pilot/fuel screw...1 turn out. Air screw out = leaner. Fuel screw out = richer. I'm trying to find out whether one should set the air screw then the fuel screw but got no reply.

[SDN]

Well, went to go down to the dyno today but started the bike and it was running like an f'in pig, wouldn't pull at all totally inrideable. Pulled the tank off and did some fiddling - worse. then put it all back to standard and ran it with tank off and remote fuel tank - ran OK, felt a bit rich, but ran - put tank on and ran like a pig - mmm - somthing fishy!

Ran it with the tank on and remote fuel tank - ran OK - checked out the fuel pump - OK, then ran it off the fuel tank on prime - result was running fine

Did a few tweaks to fuel and air screw until it ran as well as I could get it and went for a spin - awesome sound and pull. but didn't give it the beans as was not sure of the fuelling

Rode down to the cradley heath to Projex dyno and a cracking bloke called Kev stuck it on his dyno - result fuelling was spot on - his advice ride it like you stole it! £25 - bargain.

Curve is really smooth and fuel is spot on it's making 80. 17BHP, last dyno test I had the bike was making 77.6 - though they are not the same dynos so can't compare.

The really funny thing was Kev was adamant I should bin the Db killers so I took them out - guess what bike makes more power with Db killers - now who would have thought that.

Rode home with less restraint, seat of pants dyno tells me carbs feel awesome at all revs and noise is sublime!

Just got to ballance carbs and do TPS adjustment - then ride the wheels off it

[Mincehead]

Something aint right SDN you should see a MINIMUM of 8 bhp difference at the wheel just from the carb swap! Unless the dyno run you had before them was reading well high.
My stock motor makes 88 bhp at the wheel with just simple fettling and the FCR`s , stock headers and 300mm shorty 2" bore open cans.

[trixynut]

then put it all back to standard and ran it with tank off and remote fuel tank - ran OK, felt a bit rich, but ran - put tank on and ran like a pig - mmm - somthing fishy!

Fuel starvation?

Either fuel isnt flowing out the tank tap or, more likely, when you put the tank on you're trapping/pinching the fuel line?

[Killerwhale]

then put it all back to standard and ran it with tank off and remote fuel tank - ran OK, felt a bit rich, but ran - put tank on and ran like a pig - mmm - somthing fishy!

Fuel starvation?

Either fuel isnt flowing out the tank tap or, more likely, when you put the tank on you're trapping/pinching the fuel line?

I was reacting to the fact it ran ok on prime, kinked line from the inlets!? Or tap shot?

[Dav]

So...what are your final fuel/air settings?

[Excalibre]

Well, went to go down to the dyno today but started the bike and it was running like an f'in pig, wouldn't pull at all totally inrideable. Pulled the tank off and did some fiddling - worse. then put it all back to standard and ran it with tank off and remote fuel tank - ran OK, felt a bit rich, but ran - put tank on and ran like a pig - mmm - somthing fishy!

Ran it with the tank on and remote fuel tank - ran OK - checked out the fuel pump - OK, then ran it off the fuel tank on prime - result was running fine

Confirm you've been connecting the vacuum hose to the back of the fuel tap when you've been putting the tank back on?
If it's not connected, pinched or split then that may cause the symptoms you've described (although it'd be running lean on the cylinder with the disconnected/leaking vacuum hose).

[SDN]

Something aint right SDN you should see a MINIMUM of 8 bhp difference at the wheel just from the carb swap! Unless the dyno run you had before them was reading well high.
My stock motor makes 88 bhp at the wheel with just simple fettling and the FCR`s , stock headers and 300mm shorty 2" bore open cans.

Was totally different dyno on different day so can't really compare the two readings, the power curve is spot on and the fuelling ratio is spot on, so the the set up is bang on, running 150 main jets, fuel screw 1 turn out and air screw 2 turns out, needle is on second from top groove. As for the BHP who knows maybe this guys dyno is on the low side?

[SDN]

Can't really answer the tank off problem, maybe with lower fuel levels, incresed demand from FCR's the tap was struggling to keep up with the carbs? But bike ran fine on prime until I got it to a garage, filled up and put back into run position, was then OK for 20 odd miles riding + three full throttle full load dyno runs,

Hearing the bike on full load, full power was really quite awesome, you never hear it on the road, noise is all behind you, add helmet and windspeed and you hear very little really.