GTS OWNERS CLUB

Philgo · Joined: 02 Sep 2008 Posts: 2

I have a 250 GTS bought new a little under two years ago. After approximately 700kilometres it unexpectedly cut out on me and started to run roughly. When taken to the Vespa agent I was told this was caused by a buildup of carbon in the throttle and they would fix it. They did but the problem occured once again and was fixed and has now reappeared at 8500 kilometers. The service agent has told me this is normal but I don't see it mentioned in the regulare service schedule or anywhere else and the unreliability is worrying and the fact it can happen anytime quite dangerous. I also find it hard to believe that a fault such as this is "built into" the bike and is somthing I must live with.

Can anyone enlighten me? Is it normal? Is there no way of permanently fixing the problem? To date it has not survived this problem from one service to the next and I am nervous about taking any extended rides.

Some help would be appreciated Regards Philgo

CheekyThomas · Guvernor Joined: 18 May 2007 Posts: 1374

Carbon build up in the throttle Confused

Quite how would carbon build up in a place that no combustion takes place?? Where does the carbon come from?? The ONLY thing to come through the throttle body is air... and thats after its been through a oiled foam air filter.

You could get a little oil mist get sucked through if the air filters only oiled with engine oil as it always sags to the bottom and then puddles hence the little drain pots... a little of this puddle will be on the inside of the filter so get drawn in... but wont become carbon.

Have you looked at the throttle body to see if its clean?

darklord · Posted: Wed Sep 03, 2008 8:35 am Post subject:

I sense the heady smell of used bovine fodder Razz

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Vespa 300 super BSA Bantam, pushbike

CheekyThomas · Guvernor Joined: 18 May 2007 Posts: 1374

Im suspecting more oil residue than carbon build up.... but cant see why it would make the bike cut out and act badly... never had it be an issue even on super high mileage ones... would be nice to take a look and see Sad

darklord · Posted: Wed Sep 03, 2008 9:17 am Post subject:

The dealer/mechanic sounds a bit desperate for an answer to me, The only way I can think for carbon to get in the inlet would be a leaky inlet valve maybe caused by an overtight ajustment . is that possible?
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Vespa 300 super BSA Bantam, pushbike

CheekyThomas · Guvernor Joined: 18 May 2007 Posts: 1374

Yeah it could, but it would take ages.... and the engine would have to run like a dog for ages before it would get a build up.

Maver · Posted: Wed Sep 03, 2008 6:33 pm Post subject:

this is a strange one.........

sounds like a heavy dose of bullshit to me..........

whereabouts are you philgo???

we could chopper in a team of vespa specialists Wink

oh, welcome by the way Wink

have a look here......WELCOME Cool

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Philgo · Joined: 02 Sep 2008 Posts: 2

Thanks for all the input and I think your right and that I'm having the wool pulled over my eyes. The scooters back in to be fixed and I made them aware that I was not happy with their diagnosis and the ongoing problem. They looked a bit edgey when I mentioned I was seeking other opinions.

I've got a job description off one of there invoices "Remove throttle body and clean out carbon deposits" I will let you know what the outcome is when I get her back.

Cheers Philgo

Smudge210 · Posted: Fri Sep 05, 2008 12:15 pm Post subject:

All valve engines leak, think about that little valve bouncing up and down 5000 times per minute trying to seal off all them little explosions. The question is why does yours get fouled up and nobody else, for me this could be that the inlet valves need grinding or the exhaust valve seals need replacing, I think it's that way around anyways.

CheekyThomas · Guvernor Joined: 18 May 2007 Posts: 1374

Yes all valve engines leak a fraction but it is a fraction...and not enough for carbon build up on the inlet against the air flow...

jetex · Posted: Fri Sep 05, 2008 10:15 pm Post subject:

The only other way that you would get carbon build up in the throttle body, is from the crankcase breather system. Your engine would have to have covered many, many miles for this to happen, in the tens of thousands. I think they've tried to blind you with science, and sh*t themselves when you said that you were getting a second opinion.

CheekyThomas · Guvernor Joined: 18 May 2007 Posts: 1374

And even the chances of crankcase gases doing it are minimal as they get recirculated into the airbox before the air filter and refiltered before being drawn back in for reburning, so the air filter should stop most contaminants.

Blackpool Paul · Posted: Sat Sep 06, 2008 11:39 am Post subject:

Sheep, Horses, Cows, No its definately Bullshit, this is where this site really comes into its own, and is such a comfort to potential new owners, who may know the ins and outs of a cats arse with 2 strokes, but may never have seen a 4 stroke. people like Cheeky etc, always ready to help with advise, or if you live near enough, practical hands on help. All hail the mighty GTS Owners club! Wink

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GTS250 its the future!!! A club wi owt a name sc. Bamberbridge.