Hey guys, first post on here

I have recently bought an RVF400 with a full TYGA exhaust system, with a Maggot muffler. I have cleaned the carbs, synced, and fitted new rubber boots.

The bike runs fine, up until 4-6th gear, where the mid-range flat spot becomes apparent. It's worse on the highway or going above 80KM/h with wind gusts, making the bike feel like its about to die.

The bike was running:
#108 Mains
#35 Pilots
1 5/8th turns out
1x 0.5mm washer under each needle

Basically the carbs were stock, I tried changing to:
#110 Mains
#35 Pilots
2 turns out
2x 0.5mm washer under each needle

The bike runs no better, if not worse.

Is there any suggestions to fix this problem? Does anyone run a Maggot and are able to post what setup they have?

Thanks in advance

mains are for full throttle, they will affect part throttle to some extent, does it pull harder at wide open throttle with the 108 or 110s?

pilot screw is probably better off where it was.

if the 4-6k is the flat spot you could try putting a 0.5mm shim under each needle to raise the needles and richen up the mid range.

i wouldnt go larger than a 1mm shim..

Rick O sells the correct sized shims.

Flat spot is only really noticeable at speed, bike starts to break down. Down low, bike pulls perfectly up to 14.5k, but once speed is achieved, (70-80+KM in 3rd+ gear) the bike starts surging and playing up. I have read there is a sort of rubber flap (heat flap?) that goes just before the snorkel intake, would the air getting pushed directly into the snorkel, leaning the bike out cause the problem?

Am running 2x 0.5mm washers on all needles.

If you have messed with any of the airbox or intake - it runs like a dag

CMSMJ1 wrote:If you have messed with any of the airbox or intake - it runs like a dag

Airbox is 100% stock.

Just an update;

Got some 112s, 115s, 118s and some 120s, I put the 115s in the front, and the 118s in the rear to just start a base line, bike runs much better, still some sputter but way less.

May try upping to 118F and 120R and see if it just smooths it out a little more.

Where are you in the world?

ZippiT wrote:Flat spot is only really noticeable at speed, bike starts to break down. Down low, bike pulls perfectly up to 14.5k, but once speed is achieved, (70-80+KM in 3rd+ gear) the bike starts surging and playing up. I have read there is a sort of rubber flap (heat flap?) that goes just before the snorkel intake, would the air getting pushed directly into the snorkel, leaning the bike out cause the problem?

Am running 2x 0.5mm washers on all needles.

Thats werid..

is the vaccum tap working properly? vaccumpipe not split / corroded?

ive had them in the past where hard accelleration / speed would collapse the vaccum line causing fuel to stop flowing.

new vaccum hose sorted that out.

CMSMJ1 wrote:Where are you in the world?

[

I come from the land down under (Australia)

Neosophist wrote:

ZippiT wrote:Flat spot is only really noticeable at speed, bike starts to break down. Down low, bike pulls perfectly up to 14.5k, but once speed is achieved, (70-80+KM in 3rd+ gear) the bike starts surging and playing up. I have read there is a sort of rubber flap (heat flap?) that goes just before the snorkel intake, would the air getting pushed directly into the snorkel, leaning the bike out cause the problem?

Am running 2x 0.5mm washers on all needles.

Thats werid..

is the vaccum tap working properly? vaccumpipe not split / corroded?

ive had them in the past where hard accelleration / speed would collapse the vaccum line causing fuel to stop flowing.

new vaccum hose sorted that out.

Vacuum hose, I have cut each end off yo expose new pipe, hose is in good condition. Up jetting seemed to make the bike run better.

Just a question, i've heard there is meant to be a flap in front of the airbox snorkel, would this part not being in place affect performance?

at a guess if the flap that that attaches under the headstock and sits over the front plug leads onto cam cover might cause issues if missing. i am currently rebuilding an rvf and sourced one as it was missing on mine i have more experience on nc30s and they dont fuel well with snorkel flaps etc missing local dyno man told me nc35s are even more so sensitive in this area

Did see one on ebay might be worth a try if all else good .

Dynamohum wrote:at a guess if the flap that that attaches under the headstock and sits over the front plug leads onto cam cover might cause issues if missing. i am currently rebuilding an rvf and sourced one as it was missing on mine i have more experience on nc30s and they dont fuel well with snorkel flaps etc missing local dyno man told me nc35s are even more so sensitive in this area

Did see one on ebay might be worth a try if all else good .

Mine is missing on my bike, I hope that's the problem.

Should be able to get one off my other bike if it has one.

Will update soon