4th gen carb: turns of screw?

[Auspanglish]

Sorry, hands full with maintenance and no time to revise the forum for info.

 

How many turns out of the carburettor mix screw are you guys finding works on the 4th gen?

 

Manual appears to indicate 1 - 5/8 but ain't doin' it for her.

 

Gotta another 4th gen purring at 3.5 turns out.

 

Maybe the issue lies elsewhere and the difference in turns outward of the adjuster screw is due to age of certain parts.

 

Many thanks in advance for any VFR advice or wisdom!!

 

[Auspanglish]

Dutchy, long time no chat... You had a 4th gen... what say you?

2 hours ago, Auspanglish said:

 

 

[Dutchy]

Euh..... Pass!!

 

 

Long time no speak indeed...

[Dutchy]

@TheDutchy  what u say?

[RC36B]

With OEM needle, main jet and slow jet I'm 2 turns out - mixture is slightly rich at idle

[TheDutchy]

First test I would do is turn each pilot jet on each carb in seperately (Engine running @ idle) gently untill it reaches fully in.. Don't force it, because the small tips tend to break in the carb housing if you tighten it with force..

If you hear one cilinder cutting out on idle, you know the pilot adjustment is working for that carb. If it doesn''t you know that one ain't right.. Could be a faulty O-ring, plugged jet or whatever, but it will pinpoint you in the right directon which carb needs to be adressed.

 

If all are working it doesn't matter how many turns it should be out.. The preset is just a given startup to go from..

If the bike surges on idle, it can be lean.. This resultst on pops and bangs on deceleration. Also there's hesitation at pick up while riding.. A shudder jerky sensation you slighly open the throttle getting out of the corner..

 

Besides that, and also when you have to go beyond 3 turns out you might consider the slow jet being too small..  If the slow jet is too rich it would seem to have  a dip when you open up the throttle throughout the 2-5 krpm range..

 

[Auspanglish]

Thanks The Dutchy... I'll pass your wisdom on (not my bike)...

 

I'll report back on developments!

 

 

 

 

[squirrelman]

refer to service manual and follow "idle drop" proceedure

 

try indexing each screw to the point where turning it in cuts firing; from that exact point you experiment by turning out 1, 2 or 3 turns to find what works best.

 

any cylinder's screw that fails to cut out firing most likely has a slow leak through the float needle or a broken screw tip.

[Scotty750]

Hey folks, short-time lurker, new owner of '94 VFR750F 'garage find'.  This forum Rocks.

What "Single D" tool(s) are you using to adjust the pilot screws?

I'm thinking of putting a Motion Pro D socket on the lathe to thin up the wall so it will fit- any better ideas?

Thanks,

Scotty

[coupedupsubie]

22 hours ago, Scotty750 said:

Hey folks, short-time lurker, new owner of '94 VFR750F 'garage find'.  This forum Rocks.

What "Single D" tool(s) are you using to adjust the pilot screws?

I'm thinking of putting a Motion Pro D socket on the lathe to thin up the wall so it will fit- any better ideas?

Thanks,

Scotty

Factory Pro sells a D tool that fits. Slightly pricey at $30 USD shipped in the US.

[Scotty750]

Thanks CoupedUp, that will be plan B.

 

That pic of your left-side TBR pipe VFR looks GREAT.

[Toddman622]

Aaah the pilot screws. I really got tired of trying to reach those and soldered small L shaped wires on mine so I could reach ‘em.

[Scotty750]

I hear that. 

Was thinking of something like that. 

 

Plus it's a CA bike, lots of stuff blocking the right side...