Gearbox woes

[Rustyp81]

Bit of an update.

Had Chris (pugparcels) round today and managed to iorn out a few problem but still have a few things to fix.

Chris stripped the carbs down, cleaned and balanced them and put 118 jets all round. This has sorted out the misfiring and she now idles pretty sweet.

Found that i haven't got a clamp where the end can attaches to the system, Chris has advised to run some silicon round it to seal it. Obviously i'll have to wait for her to cool down.

Think i've found the source of the oil leak and again once the engine has cooled over night i will de-grease the engine and re-gasket the smup and put some chemical metal over the suspect area. The oil only leaks when it's under pressure as once the engine has stopped it's fine, could it be anything else?

But what i really need to pick your brains on is when i give her the beens she struggles. the revs will go upto about 9-10k and then the needle starts bouncing between 9-10. If i hold the throttle at 1/4 - 1/2 way open it will climb through the revs fine upto about 11-12k and then it also struggles. When i drop down a gear and pin it to over take the revs rise to 9-10k is but theres no real increase in speed. Hope that all made sense.

Could it be that i need to move upto 120 jets all round or could something else be causing this.

On the plus side manage to fix the cooling system and now the clutch works fine so a little bit of progress :D

So yeah any ideas on why she is struggling??

Cheers

Russ

[Neosophist]

It won't rev over 10k? Is it a jap bike? Have you disconnected the speedo? If the speedo restrictor is disconnected it wont rev over 10k...

[CMSMJ1]

Sounds lean. What airbox and filter have you got?


@ Neo - 5.5k is the rev limit for no speedo on these

[pugparcels]

russ has standard air box and filter, with snorkel. carbs are all standard and now run 118 jets all round. pilot screws set at 2 & 1/4 turns all round and the diaphrams have been drilled as per cammo's guide.

she starts nicely and ticks over beautifully. real smooth through the revs. as russ was saying earlier if he keeps the throttle at half open and lets the revs increase he can get all the way to the red line and the power keeps going.

if he gives it full throttle, the revs still climb but its as if the power if not transferred to the rear wheel...?

real strange, it is a jap bike but has been fitted with a uk speedo.

hope this gives you a bit more information

chris

[Neosophist]

Sounds lean. What airbox and filter have you got?


@ Neo - 5.5k is the rev limit for no speedo on these

Oh yes of course.. I'm confusing it with a ZXR....

Randomly without seeing the bike how about float heights too high? (not enough fuel in the float bowl...) causing it to go overly lean with open throttle...

[Rustyp81]

yep, just riding back from work, she was more than happy to slide through the gears as long as i didn't go over 1/2 throttle. Got me thinking about when i had similar problems with the mito. Would start fine and ride fine until you pinned the throttled and then it would splutter and hold back. Spent days stripping the carb, pv and controller. Then on the off chance brought a spare plug, changed it and problem was gone.

Now i know the mito and the VFr are completely different beasts but is it possible that the plugs are knackered and just can't spark enough at full throttle? I did drown the plugs the other day and they had to be baked? Only thing is that these plugs are that gay that surely they wouldn't be able to start the bike if they were knackered?

Hope it's not shot plugs, as a spare iridium plug for the mito is £8 a set for the Vifer is the wrong side of £40

Cheers

Russ

[Neosophist]

Check your float heights first, cheaper than plugs

[Rustyp81]

Check your float heights first, cheaper than plugs

You sir, are a genius. All the float hights were out(one was 12.5mm) . Just waiting for the silicon on the exhaust to set then i shall take her out and she if she's better. :D

cheers

Russ

[pugparcels]

well done russ, why oh why when i did everything else on the carbs did i not check them.?!? had been a long day ( thats my excuse! )

looks like i am free on sunday 29th if you still want to do the fork seals.

[Rustyp81]

hmmm.... still no better, well maybe a bit bit still don't like full throttle over 5-6kish what should i try next, bigger jets or new plugs?

To top it off oil leak has come back and i've just burnt my forehead on the exhaust manifold trying to find where it's coming from