Newbie Vibration question!

[Karl_h]

Hi all, had my vtr for just over a week now and I'm a little concerned by some engine vibration! It seems to be pretty harsh but I'm not entirely sure its not just me getting used to a big twin! I know the chain needs replacing which isn't helping but the vibration is definitely rev rather than speed related, its at the point where cruising at 4000 rpm or more it does become uncomfortable below this it is fine. I recently synch'd the carbs and that has certainly improved the low end. I can't hear any rattles or strange noises and the bike seems to be making plenty of power. It has got some remus grand prix cans on but it seems to run well enough that if it did need the carbs jetting they have been done. Could someone put my mind at rest or point me in the direction of a solution!
Many thanks Karl

[benny hedges]

the chain needs replacing

99% it'll be that.
also go round the bike make sure all the nuts & bolts are good & tight, particularly engine mounts and the allen bolts holding the footpeg hangers on.
should check them all regularly tbh

i lost the bottom allen bolt out of left & right footpeg brackets, one of the top bolts on the rear subframe and a couple out of the belly pan.
ideally undo them and retighten with threadlock.

if you are used to a inline 4 then the vee will feel totally different lol, lots of strange vibrations and noises, nawt to worry about!

[Karl_h]

My initial thought was the chain but the vibration is there in neutral! I'll check all nuts and bolts. Should my next point of call be the fuelling? From other forums I understand that constant speed it should be pretty smooth, is this right?
Cheers Karl

[benny hedges]

check the carb balance as well chap.
if tey're imbalanced, you get the effect of one cylinder dragging the other round and that would cause vibration.
you will need a set of gauges - about £20 off ebay, have a look for a set that comes with all the necessary pipes and adapters.
you need to install a m5 adapter on the front inlet stub, under the front carb.
you will see a 8mm plug which is a tw@ to get at lol.
use a bit of thread sealant on the adapter, attach a length of hose and plug it for next time - some here use a golf tee but depending what gauges you get, i got some little plastic valves with mine which work well.

the rear cylinder, break into the vacuum line that goes to the fuel tap from the rear cylinder intake stub, use a tee and length of hose (that should be with the gauges) and leave the pipe in place for next time.

to balance the carbs, get the engine to normal temp, turn the idle speed to about 2500 and adjust the balance screw which is on the left under the tank, halfway between each carb.
easier to do if you take out the 2 front tank bolts & prop it up a bit, then use a 8mm 1/4 drive socket on the balancing screw.
before adjusting the balance, check the intake rubbers under the carbs are good & tight, again with a long 8mm socket & extension bar.

if they are out you will notice the difference once they are balanced right.
give it a good rev between adjustments.

normal vacuum is between 10 - 20 mm/hg
i got these ones - http://cgi.ebay.co.uk/CARB-VACUUM-GAUGE ... 53e22eab41

[benny hedges]

just a suggestion mike, depends how he's done it.... seen a few recently with various methods involving sucking water into the engine and listening to the carbs lol....
getting it wrong might've made it worse...

cringing atm watching a woman trying to park between 2 brand new beemers lol!

[Karl_h]

I'm now starting to question if the carb balance has been done right I followed the work shop manual (carl salter) instructions but they differ from what's stated above. I had the idle at 1250. Also the fuel tank vacum pipe does this need to be connected when synching the carbs it wasn't but now thinking about it I think it should have been and t'd in to the gauge feed? Does anyone have time to write a basic but idiot proof guide to synching the carbs? The manual was a bit rubbish looking back and I want this to be sorted so if the vibration continues I know I need to look elsewhere.

Thanks again

Karl

[AMCQ46]

Karl,
The Storm is not such a smooth engine.....or at least mine is not........so it could just be that you are comparing to your old bike.

Perhaps you need to compare to another storm and see if you have something unusual with your bike. I know that mine is a pain on motorways as I get vibes through pegs and bars, and if I sit a constant speed they can be annoying. If I do the same milage on real roads, I dont notice it as I am changing the revs and moving round the bike all the time.

[LotusSevenMan]

OK. I use a set of these that are really easy to use for balancing the VTR carbs.

http://cgi.ebay.co.uk/UNIVERSAL-MOTORCY ... 4cf1ae83b9

I must admit I looked carefully and figured it out........... so made a copy. Didn't save a lot by the time you have bought the two adapters etc.

It consists of a ball bearing effectively being sucked on from both ends by the vacuum created by the cylinders around the clear vinyl loop. Very easy to use and read and no, you can't suck the ball bearing down the 'ole. It can though go full deflection one way or other; that's what I had when I first checked the bike for arb balance.
Now the point of this posting by me is that I have found that the balance of 'my' carbs was best set at 2000rpm. If set at tickover, when a few more revs were applied the ball bearing equal vac indicator (yes, the ball bearing) showed off to one side. This was consistent from about 1800 rpm up to 4,000rpm (didn't like going much higher than that with no load on the engine and the neighbours!). As soon as went back to tickover it was perfectly in the middle. So, as I spend more time from 1800 rpm to 10,000rpm than I do below 1800rpm I set it as balanced from 1800rpm up and it has been great like that!
I have added two pipes to the vac take-off and run them up to the lhs of the tank with them normally blocked off by suitable colour golf tees (but they don't normally show anyway) Makes for easy access rather than screwing in the adapters all the time.

[Karl_h]

That seems to make sense, I'm now fairly sure I just did a bad of the carb sync! Can someone just confirm that I need to T the fuel line vacuum feed with it still attached to the tank when I'm syncing? Any other little hints about synching that I should know the idea of setting the idle a fair bit higher seems sound enough to me!
Thanks again for all the replies

Karl

[benny hedges]

yes you need to tee into the vacuum line from the rear cylinder to the tank.
if you dont, the bike will cut out after a bit, no doubt in the middle of setting it up.
give it a bit of a rev between each adjustment to let it settle down.

[tony.mon]

Or if you have a scotoiler or similar fitted you'll have a tee piece halfway down the pipe from the front cylinder anyway.
If that's the case, pull the pipe out and clamp it ( mole grips are fine) with the engine running BEFORE you take the tank off.
The disconnect that bit of pipe from the tee.

Now remove the tee and connect you gauge to the bit of pipe coming from the front cyl, and of course then connect the rear cyl to another gauge directly.
this way the fuel continues to run; all you need to do is reverse the two large fuel pipes with the tank sitting backwards over the rear subframe, and you can play for hours!

(or until fuel runs out, anyway).

[pariah]

Not sure if anybody esle has considered this bit. Mine now does the same at around the 4000 mark. Riding it at high speed is actually terrible now.
What happened to mine was the oil filter blew a hole and allowed about 1lt of oil to escape . The problem is now it vibrates like hell at around 4000 and up wards, I have spoken to roger ditchfield about this and he says it,s damaged the shells on the right hand side as these are the furthest away from the oil pick up . I have noticed that more heat seems to come from the rightside of the engine now .
Engine starts , tickes over and runs fine no unusual rattles or knocks. Still has the same power when opened up but the engine needs fixing.

Just a thought that maybe over looked. Advise from roger DONT USE IT UNTILL It'S FIXED or the engine will be un repearable as it will elongate the hole where the crank sits in the casing.

My advise would be get it checked out, some one on here will give you rogers number .

[LotusSevenMan]

Pariah!
What created the situation where you manged to split an oil filter can? Please tell !!!!!

[Stratman]

I used the tube with the ball bearings in too (as recommended by Chris). I used the vacuum take off from my old negine and screwed that into the blanking plug for the front cylinder and ran a pipe to where the T connector is for the Scottoiler, so now I just have to remove the Scottoiler pipe and the blanking bolt from the front cylinder vacuum pipe to balance the carbs. I balanced at around 2500 RPM.

If you don't have a Scottoiler or a T then you need to start the engine, clamp the vacuum pipe to the fuel diaphragm so the diaphragm stays open and will allow fuel to pass when you connect the balance pipe. Bloody fiddly without a permanent front cylinder take off though and remember you are trying to remove it with a hot engine!