Hi folks.
I'm getting towards the end of my S3 resto and finally got it started today.
It kicks over ok and seems to be ok on tickover. But on full throttle their is not much response and the engine seems as if it is strangled. Its a 175 conversion, Gp crank all new bearings etc, jettex 22mm carb.
Any ideas what the issue is. Could it be the carb or is the timing out?
Many thanks.
Muffster.
Rough running
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Andy Pickering
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Timing will need to be checked with strobe and jetex could need re jetting to accommodate any extra fuel needed for the 175 kit..do you know the carb jetting..
Also what exhaust you using.
Also what exhaust you using.
Ricspeed, gone but never forgotten RIP my friend #59
as above ^^^ and is the jetex is it for a 150? maybe better with a 200 slide (no cut out)
I am playing all the right notes, but not necessarily in the right order.
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WINTERMODEL150
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Hi,if you are using a jetex 22mm carb and its a 150 then the slide will be weaker than a 200 slide so the will not cause it to be (strangled ).
Jetex 150/200 carbs are the same except from the slide as DaveTommo explains,a 175 engine should use a 200 slide (no cut out) or it will heat seize,start with a 123 main ( depending on what exhaust you are using) and work your way down untill the engine runs clean.
Make sure you are road testing it with an air filter hose fitted if not this will make the engine run weak and will have lack of power,also check the choke is coming off correctly,check for obstructions under the seat where the air scoops fitted ,also the timing will need checking as Lam 46 suggested.
Dean
Jetex 150/200 carbs are the same except from the slide as DaveTommo explains,a 175 engine should use a 200 slide (no cut out) or it will heat seize,start with a 123 main ( depending on what exhaust you are using) and work your way down untill the engine runs clean.
Make sure you are road testing it with an air filter hose fitted if not this will make the engine run weak and will have lack of power,also check the choke is coming off correctly,check for obstructions under the seat where the air scoops fitted ,also the timing will need checking as Lam 46 suggested.
Dean
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muffster
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The carb is a jettex 200cc 22mm, according to the "dealer", in the advert is said it just needs a small amount of adjustment to get it running correctly and it would be suitable for my 175 conversion.
It's my first scooter and it didn't come with a carb, i don't think this jettex one has got a cutout! No ideas what jet it's using. Carbs are a black art to me!!!
Its got a bog standard exhaust, the air hose is fitted but the seat isn't yet.
I thought the timing was set up ok, will obviously check. But what sort of strobe light do i need. i dug mine out today and its the type that needs a pos and neg feed from a battery.
Cheers.
Muffster.
It's my first scooter and it didn't come with a carb, i don't think this jettex one has got a cutout! No ideas what jet it's using. Carbs are a black art to me!!!
Its got a bog standard exhaust, the air hose is fitted but the seat isn't yet.
I thought the timing was set up ok, will obviously check. But what sort of strobe light do i need. i dug mine out today and its the type that needs a pos and neg feed from a battery.
Cheers.
Muffster.
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WINTERMODEL150
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Billy basic one that connects to a battery will be fine ,keep us posted 
Is it fitted with a GP style air scoop? (no restrictive bridge in it)
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bristolmod
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Jetex's are either good (I'm running 2 with no issues) or crap.
Suggest you get hold of a Dellorto 20mm carb and manifold (off ebay) and jet for a TV175 to see if that cures the problem.
If you are local to me I can lend you one and set it up for you
Chris
Suggest you get hold of a Dellorto 20mm carb and manifold (off ebay) and jet for a TV175 to see if that cures the problem.
If you are local to me I can lend you one and set it up for you
Chris
Scootering since 1968.
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muffster
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Hi mate.
The carb is brand new so i'd like to think it would be ok!!
However, i've spent a lot of wasted time on parts sent from so called dealers which turn out to be complete Sh@@e!
First stop is the timing then i will check the jet.
Unfortunalty for me i work in Portsmouth but live up north so i wouldn't be able to take you up on your offer but never the less, thank you for the offer.
Cheers.
Muffster.
The carb is brand new so i'd like to think it would be ok!!
However, i've spent a lot of wasted time on parts sent from so called dealers which turn out to be complete Sh@@e!
First stop is the timing then i will check the jet.
Unfortunalty for me i work in Portsmouth but live up north so i wouldn't be able to take you up on your offer but never the less, thank you for the offer.
Cheers.
Muffster.