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Having just rebuilt my series 3 Li150 Special, i had trouble with shot blast debris in my carb and tank, cleaned everything thoroughly but now I'm having problems starting the scooter, if I take my plug out, kick it a few times, put the plug back in it fires up straight away. The scooter ran great before the rebuild and the only difference is I fitted an AF 42mm clubman exhaust. Even after running for 30, 40 minutes it still won't idle and I have to keep gunning it or the engine just dies, any ideas or help would be most welcome. Got a great spark so it's pointing to the fuel or am I wrong.

Is the pilot jet blocked? use a fine piece of copper wire or a wire off a brass wire brush to check the small port is clear.

I wouldn't have thought so, I have stripped and cleaned all the carb several times including the jets but will give it another go if only to eliminate the jets

Sediment could be building somewhere in the fuel dept', An inline filter may help, cheap and effective.

Colin

No sediment left, got rid of it all and fuel system is as clean as it could be, going to give the jets another clean as suggested but I don't think its that

how long between fitting the tank and cleaning out all the sediment from both tank and carb??

Sounds like it could be flooding.....what's it run like/start like with the air hose disconnected ? (carb float sticking another option ?)

Update is, fitted a brand new carb tonight, same problem and when turning the throttle after the revs have dropped its very boggy unless I gun it it just cuts out, if I open the throttle about a quarter it revs nicely but as soon as I start to close the throttle it cuts out.

Again

Donnie wrote:how long between fitting the tank and cleaning out all the sediment from both tank and carb??

About a week maybe 10 days

electrical maybe ?? stator/cdi ?

Thats what i was wondering, in which case you may have let enough grit through to either knacker your rings or even damage the crank seals. Seen this happen before

Changed my HT lead, cap and plug, starts every time I take my plug out and put it back in, rides well enough if I keep the revs up, just won't idle and dies if I don't gun it, at a loss now, going to get the timing checked at the weekend

So, I've changed the HT lead and plug cap, new carb, still won't start unless I take the plug out, kick a few times, put the plug back in and then it starts straight away, rode around for about an hour today to get it warmed up, still won't idle and cuts out as soon as I close the throttle, plug colour looks great and when I remove it before starting it smells of petrol but isn't soaked so that would seem to rule out flooding. It doesn't seem to smoke so hopefully that would rule out crank seals being damaged. When riding it feels as though full power isn't getting through initially but then it sorts of picks up full speed at high revs, any ideas? I'm well and truly stumped

Had a similar thing with the sx150 engine fitted in my recently finished GP. I tried all sorts but it turned out to be the fuel tap not turning of completely and the float just touching the carb body and stopping the needle valve from stopping the flow completely when float bowl full. Fixed by fitting new tap and soft soldering about 0.015" to top of needle valve where it contacts the float. Starts and restarts within 3 kicks hot or cold so well that I have been riding it to work to run it in for the last 3 weeks, plug colour looks lovely. Hope you get your problem sorted.

You have to be careful if substituting carbs because jetting has to be correct. You are saying it runs but will not idle. Try Bigger Pilot jet. 48 or 50

Hi Chris you gave me the sane advice a few months ago, I fitted a 50 pilot; job done, thanks.

Colin

CHRIS in MARGATE wrote:You have to be careful if substituting carbs because jetting has to be correct. You are saying it runs but will not idle. Try Bigger Pilot jet. 48 or 50

Its the not starting that is pointing to a bigger problem, unfortunately It seems that its the problem is more likely to be the seals as mentioned earlier, getting them sorted this week hopefully, will let you all know how i get on, thanks for all the replies though

choke staying on

bigbthesoulman wrote:choke staying on

Unfortunately not, seems that the debris from my tank has got past everything and barrel, piston rings and crank bearings are all knackered, an expensive lesson learned I'm afraid