Another non starting curvy

[Citizen]

Hi all some advice needed please.

My curvy has stood for probably 9 months and over Winter in the garden, mostly covered (although not all the time) and it has come to the point where I'm probably looking to sell it as it doesn't get used enough, however I'd like the bike to be running and in half decent condition, also, who knows I might get the bug and keep it as it was always a really reliable and good bike.

Anyway long story short the battery is good and the bike turns over but doesn't fire, I have drained the carbs and now it sounds like it wants to start and will run for a few seconds with no choke before dying. Trying to cold start with the choke open doesn't happen at all. Would seem like there is no fuel getting through.

Where should I start fault finding? Should the fuel pump whine? mine makes no noise at all no click ,whine or buzz and to be honest I do not know where to start.

Cheers in advance

[Seeker]

This quote...

Originally Posted by Citizen

Anyway long story short the battery is good and the bike turns over but doesn't fire

contradicts this one...

Originally Posted by Citizen

and now it sounds like it wants to start and will run for a few seconds with no choke before dying.

Petrol has always gone "off" if left for an extended period with no stabiliser added. The addition of ethanol has made this much worse because ethanol loves water and will bond with any available including what's in the air. It forms a goopy mess (technical description) which is absolutely perfect for blocking jets on a carb.
Assuming your second quote is correct it sounds like you do have a spark (to check, remove a plug, rest it on the side of the engine so the thread is touching the engine, ignition on, press starter and see if you see a spark).

You could try draining the tank and adding fresh petrol but I think it's more likely you are going to have to strip and clean the carbs because your jets will have been blocked.

The curvy has a fuel pump but it's not electric, you can't hear it.

[R1ffR4ff]

Put fresh fuel in it.Raise the Tank and take the cover off the Air-filter and try some Carb/Brake cleaner or WD40 into it whilst cranking.See if you can get it to pull some fuel through.If you can get it running you might get lucky running half a bottle of Redex or Similar fuel cleaner through it but bikes that are left decay unless kept in Pristine conditions.
Electrical Connectors and fuses corrode and can cause circuit breaks/Problems as well as fuel systems.Brakes also seize.

Basically the bike will need a full service IMHO.

That is really good advice from both Seeker and R1ffR4ff, this forum is so useful.
I don’t know anything about curvies, but I’d tend to do the simplest things first, as they both say (check you have a spark and try a bit of carburettor cleaner in the intakes with some fresh fuel).
Good fortune.
AO.


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[Biker Biggles]

The SV needs a battery with full welly. Just because it cranks ok does not mean the battery is adequate. Jump leads from a car battery or booster pack would help. Agree about a full service after standing(dont neglect the choke plungers) and do ensure there is no water in the fuel.

[SV650rules]

Some good advice so far..

Floats stuck or pilot jet blocked up, I found that with carbed bikes keeping some redex in the fuel over winter prevented many problems, when petrol evaporates it initially leaves a sticky gum behind, which if left hardens into a lacquer - it is not as clean as you think, it is made from tree resin and dead dinosaurs after all. I used to get the 'hard to start and won't keep running' on carbed bikes, but a good 'shock and awe' overdose ( put fresh fuel and 500ml of redex in, don't mess about ) can work wonders. I still use redex in our cars and my injected AL7 and it certainly does no harm...

[mikerj]

My dad very rarely uses his curvy these days and when he does it's always difficult to start and won't idle as the pilot jets seem to be extremely prone to blocking up on them.

[Citizen]

Cheers all, this is why this place is so good for advice.

When the rain stops I'll get going on it again, the battery is on charge and going to get some easy start/carb cleaner as a first option plus draining the (almost full) tank of fuel (as an aside I was always told by the mot garage that that 97 octane fuel doesn't go off and have always used it since) and refill with new fuel and redex.

Basically trying as hard as possible to not have to dismantle and clean the carbs!

Cheers again

[SV650rules]

All fuel goes off as the most volatile fractions ( the bits that burn the best ) evaporate the quickest and you are left with denser less ignitable bits that is why bike does not want to start. Added to that as fuel evaporates it leaves sticky residue behind to gum things up, redex ( kerosene and other stuff ) dissolves petrol residue like magic.

[TamSV]

For a bike kept outside there’s the old issue with curvy’s of the fuel cap drain getting blocked then corroding inside the tank, which then allows water into the fuel.

Open the fuel cap and find the drain hole on the left hand side. Stick your WD40 straw in there and give it a good squirt.

WD40 should start dripping out from under the bike. If it doesn’t the drain is blocked and is worthy of further investigation.

Good practice to do that every now and again to keep it clear.