vibration

[yamatime]

hey everybody i need some help please i have a 2003 midnight venture with 87000 kl on it and i am the original owner.

it vibrates when i cranck it in 3,4,5 gear . now im pretty sure that it could be the u joint on it but some other buddys have a difference of opinion on this as they say my carbs need to be sinked.

so lets take a poll

carbs or u joint

[Squidley]

Carb sync is the easiest and cheapest, do that 1st. 81 kilometers is 45000 miles roughly, kinda find it hard to believe that it would be a Ujoint that soon

[V7Goose]

You don't say what RPM you are at, but the term "crank it" sounds like hard acceleration. This engine is known to shudder and pound if you grab too much throttle at too low RPM in high gear, but it usually doesn't do that in 3rd or 4th unless you are REALLY lugging it. I'd say it is almost certain you need a carb sync (and check that all cylinders are firing correctly).

Goose

[yamatime]

ok so let me explain a little further i get this vibration at right in the rear end and comes up under my seat

[yamatime]

sorry goose but when i say crank it i mean normal riding and shifting non of that beating up my bike stuff and ive only started having this problem last summer

[BradT]

Carb sync is the easiest and cheapest, do that 1st. 81 kilometers is 45000 miles roughly, kinda find it hard to believe that it would be a Ujoint that soon

 

I agree with Squid on the Carb Sync, but 81,000 km is slightly over 50,000 miles.

 

Hey Brad you better look at those little numbers on your speedo a little more often. No wonder it takes you so long to get here.

 

Brad

[kj1961]

How often should the carbs be synced?How do you check all cylinders are fireing properly???

[Scooter Bob]

Carb sync, book says every 4k miles.

 

Checking cylinders, carefully check temp of all the exhaust pipes where they exit the heads.

 

Later, Scooter Bob

[jer878]

ok so let me explain a little further i get this vibration at right in the rear end and comes up under my seat

 

Leave that toy at home

[kj1961]

Thanx Bob,just one more thing,how much of a temperature variance is "too" much?So should they be even from cold start to warm up?I just bought an 06 VSR and have been reading about this engine vibration,thank goodness for this forum,I thought I had bought a lemon,but once I got the rev's up it smoothed right out,but,I had an 87 VSR,that thing ran smooth start to finish and had way more snap than my 06,so don't know if there was any motor change from 87-06,but am deffinately riding this 06 a lot different,I do miss a tach thou.

Edited April 26, 2011 by kj1961

[muaymendez1]

I have been thinking of doing a carb synch also but the boot leak test proved possitive.

i have a leak somewhere so I left it alone until i buy new boots.

before you go for your synch check to see if your intake is leaking by shooting some strater fluid around your intake. if there is any change in rpm then you have a leak.

 

 

If there is a leak, has anyone found a way to repair small leaks without removing the carbs?

[Scooter Bob]

Thanx Bob,just one more thing,how much of a temperature variance is "too" much?So should they be even from cold start to warm up?I just bought an 06 VSR and have been reading about this engine vibration,thank goodness for this forum,I thought I had bought a lemon,but once I got the rev's up it smoothed right out,but,I had an 87 VSR,that thing ran smooth start to finish and had way more snap than my 06,so don't know if there was any motor change from 87-06,but am deffinately riding this 06 a lot different,I do miss a tach thou.

 

If a cylinder is firing, the header pipe WILL burn you, if it's not firing, you can almost hold your hand on it.

 

The 99 and up rsv has a balance shaft in the motor, which may make it act different under low rpm load, but I'm not sure.

 

Later, Scooter Bob

[V7Goose]

Maybe some of it is just a difference in the words we use, but these bikes just do not have any significant "vibration" at any RPM.

 

Improper carb sync or something wrong with the power produced by one or more cylinders does cause vibration, but you cannot blame that on the bike or say it is a characteristic of the engine - it is simply something wrong that needs to be fixed.

 

LUGGING the engine is something very different. Lugging is defined as asking the engine to produce too much power too low in the torque curve. This is not running the engine too slow, since the engine is designed to run fine all the way down to idle. It is when you ask the engine to work harder than the available torque at any RPM, and under those conditions, lots of bad things happen, including heavy vibration. This situation is especially bad on an engine with timing that is controlled by a throttle position sensor (like ours). Again, this cannot be blamed on the engine - it is nothing more than improper operation by the human jerking on the throttle.

 

"Over-square" engines with fairly short strokes in general produce most of their power at higher RPM, so you simply need to avoid asking for all the expected power unless you have the RPMs up in the power curve. On our bikes, that power curve is typically 3,000-6,000 RPM. In typical city traffic you can ride this bike all day long without even hitting 3,000 RPM and never lug it. But if you want to accelerate fast in any gear over 2nd, you better down-shift!

 

As for the temperature of the pipes, there should be no significant temperature difference on any cylinder at any time - they all heat up quickly and evenly. If you are feeling the bottom of the header pipe right next to where it connects to the cylinder head (the inside pipe, not the chrome shield), it WILL burn your finger within 30 seconds of cold start if all is working fine.

Goose

Edited April 26, 2011 by V7Goose

[kj1961]

thanx goose:)