Manky Monkey Motors

A free afternoon, the sun shining so took the XVS out today. Wouldn't run cleanly on anything other than 3/4 to full throttle. Pretty certain that it's carburation.
The carb to head rubbers are a bit perished but replacing them is going to cost over £40. So I'm hoping that they are not split right through anywhere and that a carb clean will cure things.
Still got to ride out though. Dragged out the TS125, not been run since September but second kick and I was away. It's 30 years old and has never let me down.

Very cool little bike Dave. Good to see you earlier.
Bicycle inner tube slipped over the inlet rubbers?

Was thinking along the same lines. Everything is so awkward to get to on this bike. You can't even see the carbs without taking off the tank.
 God, I love the simplicity of the trike.

Hi olds,
Will it idle is not it may be pilot jet.

How about the simplicity of "older" Brit. bikes, Dave? so much for the Nippon Invasion then!...................oh for the days of smooth bore carburettors and magnetos ;D ;D ;D ;D ;D ;D ;D

Not happy at idle either. Going to have to pull it apart, as it's virtually impossible to ride as it is.
Worrying thing is that I think that both cylinders may be misfiring, but I could be wrong. Not really had a chance to have a look at it yet.

Loved my Brit bike too. Still have a 52 BSA Bantam And miss my A10

Has it been stood any length of time?  Modern petrol only takes about 3 weeks to go off - put some redex through?

Nope, fuel is good. Pulled and cleaned the plugs, drained and flushed the float bowls and while the engine was still cold enough to touch felt for leaks on the rubbers. Nothing untoward found.
Starts and ticks over evenly now, but not going to test ride today as my back is killing me.

Please, petrol doesn't "go off" in that manner, otherwise the WW2 would have ground to a halt at a very early stage!! :D :D, heavy ends will evaporate, in time, and float bowls dry out, but "go off" I think not. I leave fuel in my bikes for months on end, and they start fine, particularly the fuel injected one! no float chamber to dry out!! Nope, look elsewhere. My XV never gave these sort of probs.but I suspect diaphragm problems, or sediment, give them a good clean, and make sure you are not sucking air on inlet or exhaust sides....Morrag

Have to disagree , with modern ethanol it can lose the light ends ( which ignite it ) fairly quickly. Most people think that the fuel has drained back from their floats  but generally it's the available light ends that have evapourated and you have to pump though enough fresh fuel to get it to ignite.

Obviously this replacement happens a lot quicker with a high pressure injection pump . I've found that it takes about 6 months for a tank of petrol to get difficult to use without adding a gallon to freshen it up.

Certainly my experience  up to date and even my 4 barrel carb doesn't want to start (without fresh fuel from the tank being dragged through) after 2-3 weeks. You can run the car for 2-3 minutes on the st fuel contained in the float chamber on that ! :)

Well, you may disagree but the facts are that other problems of evaporation as I stated, and I agree modern bio type fuels are a little more troublesome, much of the "fuel gorn off" statements are largely urban myth! bit like the number of 'For Sale' bikes that one sees advertised,that,, and I quote.."Excellent bike,Carbs need cleaning!"..yeah right... ;D ;D ;D ;D ;D still, whatever floats yer boat, I suppose, me, mine just...erm, Start! well mostly :D :D :D :D :D :D :D..Morrag

morrag, you may be right,But you are also wrong,
This modern fuel does loose it's ability to ignite,
Not so much in four stroke engines,
But two strokes definitely,
A good friend of mine had a dealership until recently,
And i can go back 15.20 years, A customer would want a test ride on a bike,
If that bike was a two stroke, And had been in the showroom for a couple of months,
It would not run,He had this same experience with every two stroke in the showroom,
If they had been stood for a length of time,They would have to drain all fuel from carbs and tank,And refill with fresh.
So in one respect it does go off.

You are correct Hunter.
The fuel will evaporate and the 2 stroke oil will be left behind, meaning it will be extremely hard to start and smokey if it does.

But there was always fuel in the tank,
Not oil.The oil was in a seperate tank,Oil injection.

What I was told by someone whose worked on bikes and cars all his life is that the modern lead-free fuel leaves an 'emulsion' like a kind of varnish, on the carb parts including the jets.  I've had problems with my Kwak after winter layups and usually cure it by shoving in an overdose of 'fuel system cleaner'.  Whether or not that's the problem, the cure works.

However as that's not the problem with the XVS it's irrelevant.

Yup, it's pain in the parts , particularly noticeable on 4 barrel carbs as it often causes flooding after even a short layup...and the ethanol percentage is set tp increase shortly:(

Didn't mean to start a fuel war  :D
Well took the bike out today and for the most part all seems good. Ticks over fine, runs ok at all throttle positions, however it there is a brief hesitancy when I open the throttle, most noticeable at low revs.
Not sure if these carbs have an accelerator pump built in.

 :'( Miss fire back with a vengeance. Would not fire on the front cylinder at all. Cleaned the carbs but no change. Checked the spark plugs, seem fine, with a good spark. Swapped the plugs around and the miss fire moved with it. One plug has a healthy spark, as long as it's not in the engine. ???  Jumped on the trike and two bike shops later I have a pair of new plugs and the 650 is running like a dream. ;D

So often it's something simple in the end!

For interest purposes only and not to fuel any argument (groan) ;D  This is a selection of unleaded fuel ranging from fresh on the left through to 3 year old stuff on the right, the third pot is 18 months and will only burn with a lazy flame. Its not too clear in the picture, the shades of  colour are very different, the fresh being a weak lime cordial colour. 

(http://i390.photobucket.com/albums/oo343/PDSheridan/Photo01-07-2014164529Copy_zpsa6cab96d.jpg) (http://s390.photobucket.com/user/PDSheridan/media/Photo01-07-2014164529Copy_zpsa6cab96d.jpg.html)

No argument from me - it's pretty bad after 3 weeks, never mind 3 years!