VTR1000f doesn't like to rev while shifting down?

[crystalball]

o.k I find that my vtr doesint like to be reved while shifting down. sometimes when reving the motor it will die and lose power this can be in any gear at any speed. but after i let the clutch out it starts up again and is all good. but im thinking not good as i would hate for the rear wheel to lock up. so looked up on super hawk forums and found this to be a common isue with the vtr. so some people raised the idel speed up a little and found that cured it. what ive done to cure it is not giving it any revs while shifting down and if i really need to rev while clutch in i only give it a real small rev. since doing this i have not had the engine die on me while shifting down. My main question is... is it o.k not to give the bike revs while shifting down can this damage it in anyway? i find im comfirtable with not reving it as its excelent engine breaking and i only need to use breaks a little. thanks for reading my story lol any help appreciated. sorry about the spelling. happy riding guys have fun and watch those freaken cage drivers.

[onearmedbandit]

It's not going to damage your bike in any way, not from a mechanical point of view. It is better for your gearbox if the engine revs more closely match your road speed, in that it's smoother on your drivetrain, however it won't actually damage anything. The other advantage to blipping however is keeping the bike level. Not blipping between downshifts say while approaching a corner at pace can unsettle your bikes suspension (pitch) and also possibly cause the rear tyre to 'chatter', further destabilising the bike.

[onearmedbandit]

Oh yeah, your engine is really for accelerating, not for braking. While it is capable of doing so, this is not it's purpose. The brakes however are only there for that reason, so use them. Don't rely on engine braking.

[crystalball]

yer i willl still rely on the breaks more but notice the vtr does have good engine breaking to tho. and yes definitaly will be very carful when choseing not to rev while down shifting.

[Guided_monkey]

How is your stat of tune. I'm thinking that at certain parts of the rev range the carbs are not supplying the correct fuel and the engine 'hesitates'.

I presume that your running standard.

I had my bike dyno'd and eliminated most of the dead zone the carbs have approx. 4600 - 5100 rpm.

Also a carb balance to ensure both pistons are receiving the same fuel.

PM me if you have further q's.

[CookMySock]

You description doesn't make much sense. How can the engine die while you are revving it?

If your bike cuts out at any time, there is something wrong with it and you should get it checked.

Steve

[jonbuoy]

If I remember rightly the issue with the storm cutting out was more due to an air lock in the fuel feed on heavy breaking - which just happened to be when people were down shifting - not the downshifting itself if you see what I mean. there was a service bulletin regarding re-routing of carb breather and feed lines. Have you got any charging or hot starting problems at all? I had intermittent battery charging problems causing a weak spark which gave me some weird symptoms on occasions.

[SS90]

The problem with the VTR1000 and stalling when "blipping" the throttle at low rpm was/is caused by having a very very lean idle circuit (pilot circuit), this is because the VTR had to pass strict emission standards (e3)

When you have excessively weak fuel settings for idle, you have a situation where you only just have enough mixture strength to keep the engine running, and this is hampered by the light flywheel that the VTR has.

When you are, as you say "blipping" the throttle, as the engine returns to idle speed, the tiny little flywheel has only just enough weight to keep the engine runing, coupled with an idle circuit only just strong enough to keep it idling, the result is, more often than not, the engine will stall.

One easy thing to do is, as you read on the website, simply increase the idle speed.

You can of course try to adjust the idle mixture screws to richen up the mixture, but there is only a small improvement, it is better to put larger pilot jets in, and retune (carb balance etc).

I think dynojet offer a kit with different slide springs, mains, and bigger pilots..... well worth the money!

But, like I say, just turn the idle up a bit, easy, successful, and free!

[jonbuoy]

The problem with the VTR1000 and stalling when "blipping" the throttle at low rpm was/is caused by having a very very lean idle circuit (pilot circuit), this is because the VTR had to pass strict emission standards (e3)

When you have excessively weak fuel settings for idle, you have a situation where you only just have enough mixture strength to keep the engine running, and this is hampered by the light flywheel that the VTR has.

When you are, as you say "blipping" the throttle, as the engine returns to idle speed, the tiny little flywheel has only just enough weight to keep the engine runing, coupled with an idle circuit only just strong enough to keep it idling, the result is, more often than not, the engine will stall.

One easy thing to do is, as you read on the website, simply increase the idle speed.

You can of course try to adjust the idle mixture screws to richen up the mixture, but there is only a small improvement, it is better to put larger pilot jets in, and retune (carb balance etc).

I think dynojet offer a kit with different slide springs, mains, and bigger pilots..... well worth the money!

But, like I say, just turn the idle up a bit, easy, successful, and free!

Wish I'd had that nugget of info a few years ago, although I never had problems blipping until the charging problem.

[SS90]

Wish I'd had that nugget of info a few years ago, although I never had problems blipping until the charging problem.

If your charging system was causing a weak spark, then that too would exasperate the weak idle situation (kind of like the straw that broke the camels back)

[crystalball]

i'm going to give it a quick rev match and not hold clutch in for to long i thibk this will cure it other wise i'll try below....
have heard of something similar, when the float vent tubes are not vented correctly, causing differential pressure in the float bowls of the carburetors. At the time, I was advised to route the tubes, so that they point downward, between the carbs, rather than side-to side. Remove the airbox to see what I mean.
are you running stock #48 pilot jets? To me it seems likely to be a lean condition causing a misfire, but I can't say for sure. I was running #45 pilots. This will affect off-idle throttle response.Most people just set their idle mixture to a recommended number of turns out from closed. Mine were adjusted - if I recall correctly - to the maximum RPM +1/4 turn or so out, to create a slightly rich idle. I borrowed the tool and set it after warming the bike up. I never experienced a dying engine, during closed throttle, unless it was very early in my tuning process - I think I do recall it happening.If I were to test this theory, I think i would take the current idle screw setting and turn it out another 1/4 turn and see if the problem goes away. I would be very interested in knowing if this is the case.