Still wont rev out

[davey]

fitted new genuine needles and emulsion tubes tonite and my valve still wont rev out when connected to the airbox , but goes great when its not.
The bike is standard apart from the toomey pipes, as mentioned in the other thread it does the same with allspeeds when i swapped to rule out the pipes.
The carbs i have were a used set i got that were pretty mank and furred up when i got them , is it possible that the air passages are possibly so blocked it would cause this problem.
Getting pissed of with it now so any advise would be much appreciated .

[arrow]

Its possible the airways are blocked. First thing I would do though is go down one size on the main jet.

[mattybeckett]

Must be running far to rich, or maybe even an obstruction in the air box or air intake path!? sometimes we cant see the wood for the trees when problems like this occur .. So frustrating i know.. but might just be something overlooked. Good luck and hopefully you will sort it.

[mattybeckett]

Also if your not to far away i can stick the carbs in my ultrasonic cleaner f.o.c no problem if you like.

[davey]

Matty thanks for the offer but im in italy so,a tad far mate but thanks .
Gary, I'm down a jet sise now and have been down even further previously but makes very little difference tbh.
Cant see any resrtiction with the airbox, looks to me all as it should.
I really think to send the carbs off for cleaning is the next step

[davey]

I just put on a set of 4lo carbs on with the jetting , needles slides etc etc from the 31k .
Same deal wont rev so im guessing it possibly rules out the carbs.
I cant think that this set of toomey pipes would afect it to this degree but could be wrong although it was pretty much the same with the allspeeds i temporaraly fitted.
Long shot although the bike suggest its way to rich if the high speed windings or coil were fooked would or could it rev out without the airbox.
Clutching at straws now i guess but better than clutching a gallon of fuel to torch it .
Its cost me a fortune this bike and its rapidly losing its appeal.
I must re state that when i bought it in the US ran great on the toomey set up which as you all may be aware is a two into one pod filter,420 main jets and the pipes .
The carb was different as was one of those linked systems which i changed for the 31k carbs for ease .
Thoughts please guys if you have any .

[arrow]

Dave, what engine is this, 250 or 350?

[davey]

Hi gary , its a 350 ypvs import from the US so its actually a 48 h rather than 31k .
I bought this and used it for about 18 months till i moved back to europe and hence i brought the bike back with me.

[arrow]

Ok, what size main jets is it currently on?

[muddyfox]

over oiled filter?

[davey]

Filter is new gen yam , and at this moment running 240 mains however have been as low as 190,s but still wont rev out with the airbox connected

[davey]

I should mention guys that when it runs low down it seems fine however ive gone up two sizes on the pilot .
Depending on what jets i have in at the time determines where the revving stops , but there never has been any accesive smoke like i feel would be present if was as rich as it appears to be , pulling out the choke makes it even worse .

[looey]

Don't know if this will help but Mark (Mech73) had problems with his low miles completely standard F2 that was running rich and not revving out.

He posted quite a few posts about it (with this one last), might be worth having a read through what he went through and did ?.

rdlccrazy.proboards.com/thread/37016/rd350-f2-running-rich

[paulincayman]

while clutching at straws.. could the pvs not be opening fully, so more air with filter off gives good mixture, filter on runs rich?,
  diagnosis by elimination...seen some pretty obscure / unexpected problems with engines over the years..
Paul

[davey]

Hey paul ,
Pv operating as they should , thanks

[paulincayman]

K.. stumped for now too..good luck

[looey]

Oct 26, 2016 14:22:55 GMT 1 davey said:

Hey paul ,
Pv operating as they should , thanks

If in doubt that the valves are opening fully (which could/would cause these symptoms), I just disconnect the pulley, peg them in the wide open position and try it.

It'll be flat down bottom but will do what it should up top (everything else being ok obviously).

I assume by what you're saying, you're 100% sure the valves are opening at the right time.

[jon]

Davey, are you running from the oil pump or pre-mix?

Jon

[davey]

Looey , tried this same deal , jon , pump rebuilt by Gary (arrow)
Thanks guys for your input

[Hardy Marksman]

If you pull out the choke and it makes things worse, then you are running too rich. Have you checked the o-ring on the float vale seat ? This is the brass insert, that the valve goes into. The o-ring seals the insert to the aluminium carb body. Also check the insert for the main jet and needle, as fuel can leak through here and give a problem. The change in fuel from US to Europe could have damaged the o-ring, or an extended time being dry, with no fuel. Don't give up, as these sort of problems are very difficult for anyone to find.

[davey]

Hi HM,
New float valve seats , new gen needles and emulsion tubes.
Really apreciating all the help from you guys , thanks .
I think im gonna go back to basics and retrace all the work ive done in the last several months to get the bike this far .

[JOHN-DYNOSTAR]

without reading the other thread.. you said

" my valve still wont rev out when connected to the airbox , but goes great when its not."

this says a lot . if the air box is connected then the bike will draw more fuel.

[davey]

This jon i understand and thanks .
If its pulling to much fuel then i would like to know where as every thing has be repaced or renewed with standard .
The only non standard parts are the pipes .

[greeny]

Go back to standard pipes.
Start from the beginning totally standard.
Progress from there.
Are pipes clear?

E

[looey]

Have you looked at/checked/swapped out the reed assembles ?. Often an overlooked item that can cause probs ?.

[mech73]

Oct 28, 2016 12:09:29 GMT 1 davey said:

This jon i understand and thanks .
If its pulling to much fuel then i would like to know where as every thing has be repaced or renewed with standard .
The only non standard parts are the pipes .

You said in an earlier post that you have gone up 2 sizes on the pilots. On my F2 I had to go to smaller pilots (from 27.5 to 22.5) to get it to rev.

Like yours it wouldn't rev out with everything standard. I removed the airbox snorkel and then it revved. With the smaller pilots it was ok even with the snorkel fitted.

[slinger]

Check your crank seals, pressure test the cases....odd jetting is a indicator of leaking cases.

[boost]

how about putting the linked carbs back on briefly to see if the bike revs ok ? got to be worth a try if it does then you've found your problem

bob

[davey]

Checked the reeds and as a matter of course put new rubbers on .
Pipes clear but dont have originals unfortunatly .
Might sound strange but im gravitating to the stator .
Im thinking that with the air box of its running so lean it would rev higher even if the high speed windings were dodgey .
Im gonna get it rewound so im gonna send it to west country windings unless anyone here knows a better outfit.
Thanks for you input guys will let you know what i find .

[JOHN-DYNOSTAR]

personally it sounds to me like you need smaller MAIN jets. when you change to performance pipes it does not automatically mean you need bigger jets.(or carbs ) It could be simply that the jets you have, do not have the correct holes for the markings on them, possibly.
It could be the exhaust you have has a restrictive baffle arrangement which gives more midrange and less top end , which ergo
needs smaller jets.