Bike will not take full throttle goes flat

[maximus1960]

Hi
I am a new member to the club and need some help to see if I can cut down the diagnostic time for this fault . I have not had the bike long and the fault came on quickly . As soon as it starts to develop good power it seems to run out of fuel and effectively cuts on all 4 cylinders. Fuel pump seems to prime and stop ok and will not resume for a good while if left standing.
Help would be appreciated before I start replacing parts.
Thanks in advance

 

[one2dmax]

Check to make sure the airbox is down tight and that the filter and lid are also in place. Too much air will make them not rev correctly.

Sean

 

[maximus1960]

Check to make sure the airbox is down tight and that the filter and lid are also in place. Too much air will make them not rev correctly.

Sean

Thanks Sean will take a look

 

[naughtyG]

Also make sure all your vent hoses are routed properly and not kinked or squashed - there's one on the fuel tank, and four from the carbs coming up either side of the air box.

 

[RaWarrior]

Could have sucked up a wad of crap and plugged up your fuel filter as well. When v-boost is open it'll suck the bowls dry in a couple seconds if the flow isn't keeping up.

Otherwise you might try the "shotgun" technique. Look in the VMF Links for a tutorial.

 

[maximus1960]

Could have sucked up a wad of crap and plugged up your fuel filter as well. When v-boost is open it'll suck the bowls dry in a couple seconds if the flow isn't keeping up.

Otherwise you might try the "shotgun" technique. Look in the VMF Links for a tutorial.

I will give them all a go and report back warriors comment makes sense in that it looses all 4 cylinders at the same time. Also the tank vent idea.
I have to say this is a Fantastic club many thanks
Dave

 

[maximus1960]

I will give them all a go and report back warriors comment makes sense in that it looses all 4 cylinders at the same time. Also the tank vent idea.
I have to say this is a Fantastic club many thanks
Dave

Ok I have replace the v shaped inlet on the top of the airbox which I had removed before and re positioned the vent hoses . this has improved it 95% I think no I may have a ignition issue as the previous owner fitted splitfire plugs which from my garage days were no good. Also I have a blow on the collector box so that may affect things they are very sensitive these things are they not
Thanks for the help
Dave

 

[naughtyG]

Ah yes removing the 'Y' on the airbox does not work - too much air so it won't run right.

Replace the spark plugs with the OEM-recommended NGK ones, they work great. All other more expensive ones are a waste.

 

[sdt354]

Try a 3/8 bushing set and longer screws on the Y. Plastic hardware store bushings work well.unk:
Steve-o

 

[Lew L]

In addition to what STD did/said----- cut some thin,stiff foam and place in in the channel where the "Y" was lifted. I did this with a few other carb mods and stock/ drilled muflers and the Max sounds great and pulls strong through the entire rev. band.
Good luck,
Lew