Speedy idle on 190 kit.... please help!

[Supereibar]

Afternoon chaps, I have finally started my SR190 GTE tuned kit with the following:

-RD400 rod
-AFflywheel,
-TS185 suzuki piston
-48mm matched AF clubman
-22mm new jettex GP200 carb run through regular airfilter set up.

The scooter runs fantastic on high revs, it has quite an amount of high power, but the problem is on the idle. Whenever I come to a stop the scooter just dies unless I revv it up or pitch the idle screw quite a bit. I started with a 42mm idle jet and there was no idle. Then moved on to a 45 (standard gp200) and there was no idle, still not enough as it would die constantly, then finally there was a speedy idle with a 47 jet, but still cannot get a "normal" idle. Its too speedy for my taste. Its almost like an airleak sound which makes me quite unhappy.

I called Sausage to ask about what he thought and his suggestion was that either I had an air leak somewhere or that the AFflywheel makes the tick over faster due to the lack of weight.
To figure out if it was an air leak, he suggested to spray break cleaner or some other high combustion product, on the intake area, the maghousing gasket and the u bend connection, to see if the scooter would speed and show a leak.

It does make sense so I tried to spray break cleaner on the mentioned areas when the scooter was running, and it didnt speed up at all. It kept idling at the same speed...

Some facts/data on it on it:

1-I have the ignition set at 19º

2- It needs just a tiny bit of choke to start when the engine is cold, then it floods really quick on tickover and dies.

3-Starts on first kick every time.

4-I have tried 2 carbs just to see if there was a problem with the carburettor, but they do the same speedy effect.

5-Choke kills the scooter instantly on idle, so it doesnt need more petrol.


I am a bit confused and dont know where to shoot at... Any ideas? Should I alter the ignition? Maybe I am using an exhaust that is too big for such a little carburettor? Would you reccomend to put a different exhaust on it? Maybe a bigger carb? Do you guys think that maybe if I should keep upjetting to lets say a 48 or a 50 jet would give me a decent idle?

Please help if you can, I would very much appreciate it


All the best,

Jaime

[RICSPEED]

try a smaller main

[bristolmod]

Hi Jaime

funnily enough I've got a similar problem on one of my TV175's with a Jettex carb

Its always started first/ second kick and has idles perfectly.

However, recently its been a pig to start when hot (it sort of "chugs" and will not increase in revs whatever you do to the throttle)- also the idle has been very erratic........

I've changed all the jets/ atomiser/ slide and gone up and down on the starter jet from 50 to 42 with no real difference, so I'm thinking one of the internal drillings may be blocked- I'll strip it again tomorrow and see whats what

I recently filled the tank up as well, so that will need investigating

If I find anything I'll shout and I know you will as well

Bleedin' Lambrettas..............................

Chris

[RICSPEED]

oh yeah ...a lot of people dont rate the jetex carbs too highly

[sideout]

mag side seal leaking? or the cross-drilling is blocked on the idle circuit?

[crooky]

hiya mate
had exact same on my af stg 4 175 kit same set up clubman and jetex 22mm put a 48 pilot in (which I thought would have been too big as dealer had no 47s) and runs like a dream. Also has a 126 main which on paper is way too rich but thats another story.
good luck with it let us know how you go on.

[Supereibar]

I have tried two different carbs and both present similar problems... I'll try the other reccomendations this afternoon and let you know how I get on with it.

Many many thanks!!!!

J.

[Supereibar]

Ok some updates... I tried a 48 pilot and the scooter idles (still very rapidly), but it floods everynow and then.. I had to turn off the tap and kickstart it several times to get an idle again. You think the main jet has anything to do with this? Any ideas?

J.

[bristolmod]

Jaime

I've given up with my Jettex and gone back to a 20mm Delly as per standard.

First kick starter; steady tickover and no problems..................Performance the same

Worth thinking about

Chris

[Supereibar]

Jaime

I've given up with my Jettex and gone back to a 20mm Delly as per standard.

First kick starter; steady tickover and no problems..................Performance the same

Worth thinking about

Chris

Chris... are you for real sir? I dont think with an SR190 tuned to the tits is a good idea to go back to a 20mm.....


J.