Gilera DNA 50 wont start

[andy-iow]

I have a 2003 Gilera DNA 50 that i just cant seem to get running,

I have a strong good spark at the plug and have tried a few thing on it but still no good, Air filter is clear, Fuel pump and fuel Tap are fine , exhaust system if fine, The timing you just cant get wrong (unless you forget to put the key in when you fit the flywheel) and the fuel is only 5 days old I have also just just fitted, the parts listed in the hope to sort it out,

1, New spark plug

2, New 17.5mm carb

3, New reed valve

4, New Inlet manifold

5, New Base, and cly head gaskets,

6, New crank case gasket

7, New Crankshaft seals,

and when I say new I mean new not second hand,

all the above i have tried with a gravity feed fuel tank, and with all the vacuum pipes blanked off just in case of leaks

and i have tried it with and without the exhaust on, I'm now out of Ideas,

The only thing I have NOT tried yet is a piston, rings, barrel and head as I have compression on it,

If I hold my hand over the intake before I changed the parts I could get it to fire but that's about it and its the same with the new parts

Thanks Andy

[oldie59]

Possibly a silly question, but have you tried using the choke if indeed your bike has one fitted? You say the bike fired when you put your hand over the intake, this effectively is what the choke does. It stops or reduces the air entering the cylinder(s) and allows more fuel in. Your bike by now has been standing a few days at least, and will need this to start it agian.

One other thought, has your new spark plug been set at the right gap? Too large and the bike will struggle to start if at all.

[andy-iow]

the bike has a auto choke on it both on new carb and the old one. Plug gap is to the gilera specs

[andy-iow]

Its got a new automatic electronic choke

[Grumpy Old Git]

Its got a new automatic electronic choke

 

But... is it operating?

Have you set the new carb up correctly?

When you check the plug - is it wet? (if not then fuel is NOT getting through correctly).

Have you tried putting about a 1/2 teaspoon of fuel into the cylinder, fitting the plug and trying to start?

[oldie59]

How are you getting on??

Hope you have got it sorted out by now

[andy-iow]

Yes the coke works fine,

fuel not getting to the cly has been the problem all along, that's why I have done all the seals, gaskets, Reed valves and new carb,

[andy-iow]

yet oldie59, on 6 days rest now (work shifts) so will be looking again,

Trade wise I'm a HGV mechanic, Give me a 4 stoke derv engine and ill do it blind folded,

only 2 stokes i've done was when i was in my teens, Going to show my age now 2 stokes had points and the piston was the only valve, and the carb bolted to the barrel, lol

no reed vavles and no CDI's lol

[oldie59]

yet oldie59, on 6 days rest now (work shifts) so will be looking again,

Trade wise I'm a HGV mechanic, Give me a 4 stoke derv engine and ill do it blind folded,

only 2 stokes i've done was when i was in my teens, Going to show my age now 2 stokes had points and the piston was the only valve, and the carb bolted to the barrel, lol

no reed vavles and no CDI's lol

 

I used to own an RD250 Yamaha and later a 350YPVS Yamaha, also owned a Triumph Bonneville 750 T140v amongst other bikes. So now I am showing my age as well.

But then my user name gives it away

[eastanglianbiker]

you need to be checking compression in case either the rings are worn or the crank shaft seals have gone

[andy-iow]

Never had a Bonneville I had a 59 tiger 650 twin until 1981 and a BSA a65 650 twin but the 1st bike I had was an FS1E when I was i6 and a Suzuki gt185 when I was 17 lol

[andy-iow]

Seems to have good compression and I done crank case seals last week

I thought might be piston related so I just placed an order for a 70cc big bore kit