BIKE WONT HOLD IDLE AND SPUTTERS AND BACKFIRES

[Casper92]

Hey guys so I just bought my bike. It rode mint for about 40 mins loads of power everything. I stopped to fill up as the low fuel light came on then rode another 30 mins then when I came to a stop at traffic lights the bike cut out, it fired back up but wouldn't hold idle and was sputtering and backfireing in low RPMs, now it won't go faster than 75mph.

I'm gonna clean carbs tonight and check the plugs, air filters and hoses etc any other ideas?

[Wicky]

Greetings, not a good start.

First check the vacuum hose on the fuel tank is on securely right spigot and not split. Also worth checking that the rubber diaphram in the fuel tap is in tip top condition. Handy Hint take pics as you go along as refrence before disassembly so you have a rough idea of how things were (plus as evidence of any shoddy goings on to show PO if you get in dispute etc.)

Was the bike laid up for long time before you got it?

Check the workshop knowledgebase forum section esp for downloading the factory VTR service manual PDF for reference.

And post some pics of your new super Storm beastie.

[Casper92]

Hi, well I took it a part, checked the plugs... The front one is like black and oily where the rear is white and dry, both give a good strong spark.

[Casper92]

Also, the bike was laid up for a year and only didn25 miles

[tony.mon]

Black and oily is a problem....
It's the oily aspect that is a concern; if its running rich it isn't oily, just dry soot.

The other cyl is OK, which rules out misfuelling with deisel...

So the next step is to get a compression test, which will reveal whether it's rings or guides/seals.

[Casper92]

Black and oily is a problem....
It's the oily aspect that is a concern; if its running rich it isn't oily, just dry soot.

The rear cyl is OK, which rules out misfuelling with deisel...

So the next step is to get a compression test, which will reveal whether it's rings or guides/seals.

Bottom 2 are the rear cylinder, top two ante from the front cylinder (by the wheel)


There is some pictures of.the spark plugs. Please make your own judgement and let me know. I may be totally off with it being oily instead of carbon

[tony.mon]

OK, the bottom two are wet, but is it oil or petrol?
Don't clean iridium plugs with a wire brush or anything mechanical, you can wash in petrol or brake cleaner (trichlorethenol) though.
Try that and put the plugs back in and see if it'll run OK for a while before the problem returns.

If it stood for a year, the carbs are probably in need of a clean anyway.
But a gummed-up jet won't cause overfilling, so this shouldn't be connected with your problem.

You need to find out if it's oil or petrol causing the plug to get wet.