Two problems

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Tabian
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Mon Jun 30, 2014 4:52 pm

I have a GP 125 with a 185 engine only had it for about a month. The first problem is it runs for a mile or so and then stops. When I start it from cold full choke no throttle it starts on the third kick and then stops, I will kick it over another two or three times before it keeps going if I give it some throttle it will die so this has to be done slowly but when it has got a hold it revs OK. It doesn't like having the choke turned off, mind you I have never had it running long enough to get it fully up to temperature. I fitted a new Jetex 22mm carb, took out the tank and drained it and cleaned the filter tap then refilled the tank with fuel mixed outside the tank in measuring bottles....

The second problem is it keeps spitting out of fourth gear, it keeps in gear if I hold it there... I am not much of a mechanic to say the least.!

Any ideas please..

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rosscla
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Mon Jun 30, 2014 6:15 pm

For your gear jumping it could be the cables just needing adjusting. Sounds like the one that moves down the gears is too tight. Turn the gear change and watch the action at the top of the engine and you''ll see how it works. If it's not simple cable adjustment then it could be the gear arm in the wrong spline or worn selector or pawls in the gearbox itself.

Best thing you can buy is a copy of Sticky's book or a mate who knows Lambrettas :)
"Our dilemma is that we hate change and love it at the same time; what we really want is for things to remain the same but get better."

mick1
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Mon Jun 30, 2014 6:49 pm

Regarding you carb' issue.......check your breather hole is clear in the fuel cap.....just a thought ;)

.....another thought !! try without the rubber on the carb' (could be blocked air filter)..

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purple_pill67
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Mon Jun 30, 2014 9:22 pm

Or maybe the tie bar catching on the rear shock esp if its a cheapo one or worn old one....mine did the same, could see it riding up when you changed gears whilst not running/on its stand

soullad
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Mon Jun 30, 2014 10:01 pm

Tabian wrote:Any ideas please..
Ask about and find a reliable trustworthy scooter dealer in your area, ask him to give your scoot the once over, esp the engine to check everything is as it should be. It'll be money well spent in the long run trust me.
A reliable Lammy will hook you for life, but a bag of nails will drive you up the wall and cost you time and money you never thought you had :shock:

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Tabian
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Mon Jun 30, 2014 10:07 pm

Thank guys I'll see if I can have a poke at it tomorrow. As far as the carb goes it looks as if it's getting starved of fuel, is that something to do with the mixture screw?

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Tabian
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Mon Jun 30, 2014 10:16 pm

soullad wrote:
Tabian wrote:Any ideas please..
Ask about and find a reliable trustworthy scooter dealer in your area, ask him to give your scoot the once over, esp the engine to check everything is as it should be. It'll be money well spent in the long run trust me.
A reliable Lammy will hook you for life, but a bag of nails will drive you up the wall and cost you time and money you never thought you had :shock:

I live up near John O' Groats and there is no Lambretta (scooter) dealers here, people just look at me as if I was flying something from outer space. There is a mannie up here that fixes motorcycles maybe a word in his shell like may cast some light on it.

Thanks for all...I'll let yall know how I get on with it...

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paulnobodyimportant
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Tue Jul 01, 2014 1:19 am

As already suggested, try running with your fuel cap loose,but just for a few miles. I rebuilt a GP and had exactly the same running problem that you describe to a T. Back in the garage checked my fuel flow and found that it ran very slow. Then when I took the filler cap off, the fuel ran ok. Put a new filler cap on and ran like a dream.
The breather hole is very small and difficult to tell just by looking at it if it's blocked, but blocked it creates a vacuum in your tank and starves fuel. Couldn't believe something so simple screwed things up so much. As for gears, just sounds like badly adjusted cables. As suggested, get Stickys book and have a go, its simple.

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gix
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Wed Jul 02, 2014 4:23 pm

Check your plug gap too :-)


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1968 SX150 Apple Green

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Tabian
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Tue Aug 12, 2014 8:49 am

I was told when I bought this scooter that it had had a 185cc engine fitted 800 miles back. Well that turned out to be a bag of elephant poo, it was a 125, the gear box was knackered and when I took the head off you could wobble the piston from side to side all in all the engine was well and truly Donald Ducked. So it was hand back into the pocket again for a band spanker 200cc SIL factory built engine and it runs like a dream. I go for a run every night after tea and do between 70 and 100 miles but after a good run the spark plug gets to black to start the next day and needs a good clean first. Is there anything I can do to rectify the problem....?

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