bike fouling plugs on hard braking.

[Cptorange]

Was leathering the old storm round Castle combe, and noticed that on really hard braking into chicanes, the bike sometimes felt like it fouled the plugs. ie no power/misfiring, but then would clear its throat after a sec or 2 on WOT.
The bike is on std jetting, 48 pilots and slip ons.
Turning the idle up to 1500 from 1200 helped.
Waddya reckon??

[lloydie]

Normal for the VTR . You need to reroute the carb overflow pipes . They come out the sides of the carbs and cross and sit between the carbs .
Just pull them out from the middle of the carbs and let them hang down .
Simple fix

[jchesshyre]

What he said. Honda even released a data sheet about this once it became clear that it was an issue (unlike what happened re the camchain tensioners where they denied entirely that there was an issue!).

[8541Hawk]

[Cptorange]

cheers lads, will give it a go. Thanks for the info.
Just for the record, the std calipers/MC are amazing with new EBC x x series discs and hh pads. I had the back wheel in the air from 100mph. Don't know why folk change the the calipers etc.

[Cptorange]

Gotta ask, how does pointing the hose downwards help the situation?

[8541Hawk]

Gotta ask, how does pointing the hose downwards help the situation?

Well what actually fixes the issue is removing the hose from the stay. Which way it points from there is rather inconsequential, though if the hose end was pointed up it could fill with fuel and not drain properly. With all that, my fix was to just remove the 2 vent lines. Been running that way for over 20yrs with no issues.

[Cptorange]

So it just pi**es fuel out of the front vent hose when you slam the brakes on?
If so, may have to get a catch bottle, gotta be risky if it gets all over the header pipes/track?

[8541Hawk]

So it just pi**es fuel out of the front vent hose when you slam the brakes on?
If so, may have to get a catch bottle, gotta be risky if it gets all over the header pipes/track?

Fuel would only come out if the float sticks open. Braking will not cause fuel to come out of the bowls. It is air flow that was restricted with the hose in the hole in the stay. Again, been running with no vent hoses for over 20 yrs and 100k miles and have never had fuel come out the bowl vents, though YMMV.

[tony.mon]

I've noticed that the pipe flattens as it bends 90 degrees into the carb frame, it could simply be that restriction that causes the problem. Either way, pulling them out sorts it.