Flooding Carb & Massive Spit Back

[Granty]

Guys -- running the 30mm delly today & changed the atomiser down. stupidly left the chock on & ran it for about 1/2 mile before I realised -- I've changed the atomiser back to the meaner one but the engine will not tick over and the spit back out the carb is horrendous -- any ideas before I chuck it through a window.

could something just be stuck?

[Cgt75b]

Yeah the choke.

[Granty]

Carb stripped today - nothing seems to be stuck and defo not the choke -- but here's the strange bit.

On a wee ride today everything going great up to 1/4 throttle and then up to 1/2 throttle. When I opened it up to 3/4 - full throttle scoot running well for a bit then when I rolled the throttle back it felt like the carb was flooded and it just wouldn't rev at all and really boggy. Left the bike for 10 mins, started it and ran well again at 1/4 throttle home again -- anyone had this before and any ideas? - G

[CHRIS in MARGATE]

Have you got some of air filter on there? If so, you'll have to remove it.

[Granty]

Have you got some of air filter on there? If so, you'll have to remove it.

Open mouth carb Chris -- absolutely crazy -- goes OK up the throttle but bogs down something horrendous on the way back down -- G

[Rich Oswald]

Have a check to see if your clip on the needle has moved or even come off?

Rich'

[Granty]

Have a check to see if your clip on the needle has moved or even come off?

Rich'

Hi Rich -- checked that last night and clip is still in place 2nd from the top --- now going to replace the atomiser with a new one just in case the old one has been modified in any way. its the strangest thing -- up to 1/4 throttle all is well, up to 1/2 throttle a bit boggy, on 3/4 throttle goes well but then it feels like someone has just chucked a load of petrol in the carb and it floods on the way back down.

[Warkton Tornado No.1]

I presume this is a PHBH 30 mm.

Your symptons sound like you have the needle moving out of 'register' with the slide, alright on the way up, sticking on the way down. But how?

Although you say the "clip is still in place 2nd from the top" have you ensured it is under the needle retaining plate & not above it?

It would be an easy mistake to make.

[Granty]

I presume this is a PHBH 30 mm.

Your symptons sound like you have the needle moving out of 'register' with the slide, alright on the way up, sticking on the way down. But how?

Although you say the "clip is still in place 2nd from the top" have you ensured it is under the needle retaining plate & not above it?

It would be an easy mistake to make.

You know what, I think that's the ball game right there, I'm sure the needle clip is above the retaining plate on the spring side rather than underneath the plate, this would mean that it's coming up with the slide but is "floating" on the way back down. Up to the man cave tonight I guess.

[hullygully]

good job you went in car to hand those stickers out on saturday

[Rich Oswald]

good job you went in car to hand those stickers out on saturday

???

[Paulnobodyimportant]

Although you say the "clip is still in place 2nd from the top" have you ensured it is under the needle retaining plate & not above it?

Oh dear, that explains a lot. For the last 8 years, I have been sitting the needle clip on top of the plate and often wondered how it sorted its self out when dropping off the revs. Just checked a few Dellorto diagrams and you are correct and it all makes sense.

Here to some happy jetting at last.

Many thanks from a grateful Dork

[Granty]

good job you went in car to hand those stickers out on saturday

Wrong Granty Buddy -- this one is from the ELSC Chapter -- G

[Warkton Tornado No.1]

Remember that if your jetting was anything like correct with the clip above the plate, you need to move the clip to a groove below & possibly more. You can fiddle to get fairly close with the shims that we all should have. I know I have some, it's finding them that is the problem....

[Granty]

Remember that if your jetting was anything like correct with the clip above the plate, you need to move the clip to a groove below & possibly more. You can fiddle to get fairly close with the shims that we all should have. I know I have some, it's finding them that is the problem....

Many thanks for your help, the clip was the issue, now I have the clip in the right place and all well, can't thank you enough. Jetting scheduled for Friday afternoon with more jets, atomisers you can shake a stick at, currently have the set up below

30mm delly open mouthed
42mm Clubman
Stage 4 200 lump
50 pilot
40 slide (a wee bit worn)
AV266 needle jet
X7 needle clip 2nd from top
125 main jet

Let's see what Friday brings -- hahaha

[Toddy]

good job you went in car to hand those stickers out on saturday

??????

[Paulnobodyimportant]

Remember that if your jetting was anything like correct with the clip above the plate, you need to move the clip to a groove below

Yes, I did think that and will look at 2 of my lambretta's tomorrow. It all makes sense and I don't know if over the years I made a quantum leap to place the needle clip on top of the plate, as both scooters have been dynoed in the past.

But it does now explain why I am struggling to jet in my tuned monza up to half revs and getting random 4 stroking; the needles not dropping down to the right place, (30PHBH). The other one is a TS1 with a TMX35, so I will have a look at that and see if the needle clip is located correctly as it does seem erratic when dropping down to low revs.

Phew, here's looking forward to some smoother riding and easier jetting in.

[hullygully]

sozzzzzzzzzz it was ste-veg