V force 3 reed valve going bad????

[Jdbarnes89]

I have a ET 967 in my backie Chan that runs great except for at idle and it keeps getting smoke back through the carbs after idling in to shut down, and it has a really loud knock sounding idle with the hood on which i think is due to back flow through the reeds, runs flawless off idle and I'm almost doing 2 consecutive flips, but idle is screwy, i not even a month ago replaced reed pedals, carbs are tuned and ignition is 18° at idle, static timing is spot on, so my question is do the reed cages themselves wear out? I have no idea how old they are, the engine has vf3 cages, php 48mm intake, 48mm dual Novi, PFP new last fall with a jetmaniac laydown waterbox, it used to have dual sbn 46 and it did the same thing, trying not to just toss random expensive parts around lol, thanks for any input!!

 

[Jdbarnes89]

Just checked it, it's 175 each hole cold

 

[hornedogg79]

Did that waterbox fit without modifying it? Does the exit hose have space between it and the manifold? I had to grind a sharp corner off the front of my php manifold so it wouldn't dig into my hose. Looks like you may have a coupling there too. Could be the knocking and the exhaust leak.

 

[Jdbarnes89]

Yeah everything fit really well, there is plenty of clearance between all exhaust hose, i am kinda thinking I'll replace the reed cages, even when parked on the beach stand when a wave hit the back end you could see it pushing exhaust back through the carb, the cages are from 2014 i believe, at least that's when the build thread on the original engine i bought the ski with was made

 

[long beach local]

Smokey carb carbs = reeds probably. I don’t seem to get a lot of hours out of either Vforce reeds then they break but at least is doesn’t destroy the motor. The best longevity in my experience is stock reeds with the standard boyessen fiberglass replacement but who wants standard stuff lol.

 

[Jdbarnes89]

Yeah i ordered some new cages from jet maniac, I'll be putting them in on Monday then I'll report back, i called Moto tassinari and they said to send my current cages in and if the cage is bad they will replace them

 

[spinyard]

my vforce last a long time...

 

[Jdbarnes89]

Well these i believe are from 2014 when the ski was first built, the ski runs fine at higher rpm but at idle it don't, not sure how to best explain it but i went through a no wake today and when i got home and popped the hood the was a puddle of fuel mixture on the head of the rear cylinder, i guess that leads me to believe the cage isn't sealing correctly?

 

[JKMike]

Well these i believe are from 2014 when the ski was first built, the ski runs fine at higher rpm but at idle it don't, not sure how to best explain it but i went through a no wake today and when i got home and popped the hood the was a puddle of fuel mixture on the head of the rear cylinder, i guess that leads me to believe the cage isn't sealing correctly?

I had something similar happen the other week, after a riding session i found fuel mixture sprayed on my Ebox right by the rear carb. Although in my case the Motor, Carbs and reeds are all brand new. XS 1060, VF3 Reeds, Full Spec 50's. I'm curious if having fuel mixture spray out of the carbs is an automatic sign there is something wrong with the reeds?

 

[Wetbuffalo]

I had something similar happen the other week, after a riding session i found fuel mixture sprayed on my Ebox right by the rear carb. Although in my case the Motor, Carbs and reeds are all brand new. XS 1060, VF3 Reeds, Full Spec 50's. I'm curious if having fuel mixture spray out of the carbs is an automatic sign there is something wrong with the reeds?

In my experience this is pretty standard with vf3 reeds. They do not seal all that well and back spray can be common on a used motor. Now if everything is new, I might chalk it up to a crappy set of reed cages with excessive casting flash on the parting lines.

In a performance motor I will typically take a new set apart and try to flat the internal reed block as much as I can.

 

[hornedogg79]

Good needle/seats? What is your pop off pressure set to? When I started trying combos I would get hesitation on the second flop. Pull the hood and would have fuel mix all over my hood liner. I ran the ski on the hose and watched my carbs with flame arrestors off. Tuning felt nice and crisp and looked to be atomizing nicely but when I would hammer full throttle for a second and let off, fuel would dribble out of the booster. I ended up putting new n/s in and raising my pop off. Then had to increase my pilot jet to get my adjusters back near 1 turn out. You could also try increasing the size of your return line restriction to reduce fuel pressure. Not saying you don't have reed issue. You should check for sure. Reeds can have the slightest gap but still seal just fine when crankcase pressure is positive. My vf2 cages are from the early 2000's I think. I bought them used in 13 and replaced the reeds once. Still look great.

 

[Jdbarnes89]

So the top cage is new bottom used you can see the dark spots, it's almost like the cage itself is burned and pitted in them spots and not a flat surface anymore, i put new reeds in the old cages about a month ago and they are already all chipped up where the dark spots are, the middle reeds are worse then the outer, but i didn't get any pictures cause I'm lazy, i no longer have exhaust smell coming from carbs or much spit back