my VTR appears to be back firing,

[Taz69]

Cheers guys,

I am going to sort out the vac hose tomorrow, I will also check the insulator bands between the carbs and cylinder heads just to be sure while I have it stripped down.

Is it worthwhile changing all the hoses due to age or just go through each one by one?

Mark

[lloydie]

Check each one to be sure .
You can get vac hose of eBay
If you can't get to a scrap yard


Sent from lloyds iPhone 4 using Tapatalk

[Taz69]

Thanks chap, I have not had chance to get to it today but I am going to Halfords in a mo to see what hose's etc they have.

Mark

[Taz69]

Hi Guys,

I have been busy lately, kitchen, decorating etc, anyway I managed to get the balance gauges on the Storm tonight and the rear cylinder does not seem to making the gauge move at all, the front one is bouncing the gauge up and down, its a carbtune 4cylinder unit, I have set up the vacuum pipes from the front cylinder take off, put a t-piece in the rear one as well as replacing the whole length due to deterioration. But the rear gauge does not appear to be moving, I have removed the carbtune from the rear pipe to check it has vacuum, which is does, its working the petcock aswell for the tank.

Any ideas please?

Thanks
Mark

[benny hedges]

you need to restrict the front one a bit to get an accurate reading.
try twisting some fuse wire round the pipe or pinching it with an adjustable spanner.
some gauge kits you get small restrictor valves included.... (like mine)

dunno what's up with the rear one if you cant get a reading - check the pipe isnt blocked..... have you tried sucking on the gauge to see if it's broken?
if it's a 4 cylinder kit just use a different gauge

when you adjust the balance btw, the front cylinder stays the same - only the rear one will change.
all you are doing is adjusting the speed of the rear cylinder to the front


if you cant get a vacuum reading at all there is something more serious wrong with it.... net step is to check the carb diaphragm on the rear cylinder....
and compression test on both cylinders.

[Taz69]

Benny,

Thanks for the reply, I will try that tomorrow, there appears to be suction to the rear hose as when I disconnected the tube to the balancer I could feel air when I put my finger over the end of it.

Does the revs need to be at a certain figure? I had it running at around 15/1700 rpm! is that ok?

Thanks

[benny hedges]

turn it up a bit to about 2500 and make sure it's at proper temperature before adjusting.
give the throttle a good blip between adjustments.

[Taz69]

Ok mate will do and will reply asap.

Mark

[tony.mon]

Check hoses all the way through for the rear one, as they are often cracked.

And if they're ok, and you still get no reading from the rear one, check the fuel tap diaphragm for splits, which could be causing your problem anyway.

[Taz69]

Tony, thanks for the info, I have replaced the vacuum hose for the rear, is that what you mean?

I presume when balancing the carbs, the airbox is off, which also means the thicker hose's from the cylinders are open aswell! As this is what I picked up from the workshop pdf by AMQ I presume this is ok?

Thanks

[Taz69]

Hiya,

I have checked the hoses, they appear to be ok, I have ran the bike up, warmed and running at just over 2k, the gauges appeared to move up a little to 10 on the carbtune gauge, when I blip the throttle it raises the gauge up, when it settles back down, the front is little higher than the rear, by say 11 to 10.

On the front Carb, the slider was moving to an fro a little, the back carb was still unless I put my finger down towards the gap then it moved to an fro.

I am feeling a little lost on this, with it being my 1st carb balance. Is anyone in Bristol that is willing to pop in and say Hi and just take a general listen to her for me?

Thanks
Mark

[Taz69]

A little update.

After having it running a while, its still popping, back firing on idle, would it be a good idea to get the carbs cleaned? they appear to be fairly easy to take off, I am sure someone on was offering a sonic clean service for carbs, maybe I am wrong, but I need to start looking somewhere don't I?


Mark

[Taz69]

I have found a local bike garage to me who have said, if I strip the jets, bowls etc they will ultrasonically clean the complete carb set, jets etc for £25, this seems reasonable to me, would this be a viable option?

Mark

[sirch345]

Tony, thanks for the info, I have replaced the vacuum hose for the rear, is that what you mean?

I presume when balancing the carbs, the airbox is off, which also means the thicker hose's from the cylinders are open aswell! As this is what I picked up from the workshop pdf by AMQ I presume this is ok?

Thanks

Taz, no, the air box should be fitted as it is when the bike is being ridden with the thicker hoses as you call them connected

Chris.

[benny hedges]

A little update.

After having it running a while, its still popping, back firing on idle, would it be a good idea to get the carbs cleaned? they appear to be fairly easy to take off, I am sure someone on was offering a sonic clean service for carbs, maybe I am wrong, but I need to start looking somewhere don't I?


Mark

just wondering... dont want to worry you like, but do the camchain tensioners look new?
does it look like the frony cyl head gasket has been changed recently?
im wondering if the previous owner has had a cct failure and slightly bent a pair of valves?

are you absolutely sure there are no air leaks around the carb rubbers, exhaust ports, headers or link pipes?