Scooterotica

Well thanks to the top tips of you lot I have been in my shed 'tweaking'

It's gone 'reasonably' but not 100% to plan

The clutch work went well but the blasted crank case now leaks oil BADLY!!
The new gasket is far too thin (I didnt notice) -- about 1/3 of the one that came off... So a redrain and silicon is required to sort. ill probably replace the bolts with studs at the same time.

The expansion chamber and carb mods have made a massive difference .... revs really responsively and sounds great... rides well (sort of LOL)

HOWEVER ..... theres always a however!

The carb will not allow idle/starting unless the choke is on. As soon as the choke is turned off it dies unless i rev past the idle jet position where it runs really well...

I have swapped the idle jet to no avail and am thinking that the idle circuit may be blocked??
Putting my hand over the carb when starting is dry.... untill the choke is on, then its wet

Any ideas guys? The carb is an OKO mikuni copy, straight out of the box (apart from re-jetting to suit what was used by others)

Thanks for any input

GP200 SIL engine
ScootRS series 2 expansion (lovely bit of kit)
OKO carb (30mm I think) -- not so lovely -- but looks nice LOL

Julian

Sounds like it needs a bigger pilot jet.

GP Kevo wrote:Sounds like it needs a bigger pilot jet.

Thanks for the reply

I went from a 32 to 40 yesterday to no avail
It's as if there isn't a pilot jet even fitted. There is not a hint of fuel at low throttle as far as I can tell

I am considering stripping the carb and boiling the body in water with lemon juice to make sure the passageways are clear
I did notice a small bit of crap in the bowl when I re jetted. I run a fuel filter so I think the crap may have been there from the off

Time for a cup of tea and strip down metinks

I would strip the carb then an easy way to check the circuits is to use a aerosol with a thin pipe and spray down all the drillings watching where it comes out.If you spray down the idle jet drilling it should come out a small hole just behind the slide seat .Also remove the front airscrew and spray down the hole.You could have a faulty carb if all the idle circuit is not linked and an airline does not blow any crap out.

It was a major problem in the end......

it was the pillock that did the installation work!!!!

Oh hang on---- thats me!

User error basically.
In my haste to tinker I had forgotten that I had jetted it for use with a remote air filter.
Obviously (prat) I was tinkering with the mouth open.

A combination of air filter on and airscrew setting + idle adjustment and it 'magically' started to tick over.

Its still not right as its running on 1/2 turn out but at the mo I'm leaving well alone.

I'm dead happy as its clearly not a blockage issue.
I'm amazed at how subtle the difference between not running and running ok is wrt 'minor' carb tweaks.

Oh and it runs like a different scooter (sounds like a motorbike lol) ... 10x more responsive than the Jetex/Clubman setup I had before. And I can lean into right hand bends now without the exhaust scraping the tarmac.

Feel free to hurl abuse and generally extract the urine.... It's well deserved.