ET4 187 Project, NEW UPDATE
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Member
Et4
Joined: 05 Jul 2018
Posts: 13
Location: Lancashire
Sat Aug 18, 2018 2:42 am quote
Enjoyed reading this, Iíve just fit this kit along with a pm tuning exhaust and a Vespa gt125 carb, Iíve not yet upgraded the gearing, it does need tweaking, fuel starvation issues after half revs, Iíve changed to a bigger fuel line and stripped and cleaned the carb again, another problem has shown its face, brake light stuck on, both switches are good and can not find a short on the loom (using a meter to check), suspect dodgy lamp holder

7CCB20DD-D68C-4C18-9452-647D60DF69BA.jpeg

Hooked
ET4 187
Joined: 14 Mar 2017
Posts: 231
Location: Germany
Wed Aug 22, 2018 12:35 pm quote
@Dazzerlancs, congrats on the upgrade!

The necessity of tweaking different components is exactly what I'd hoped to eliminate. My biggest fear was carb issues if I'd upgraded along with the cylinder.

If you have the original carb, probably a Walbro, put it back on. Provided it was in working order of course. A Keihin CVK 26 is also quite OK for now. These carbs are enough for the beginning, we can change them around and do small adjustments at a later date. First lets get the motor working properly.

I notice you have new brake lever(s). If they're of the Alibaba sort, this may just be the culprit for brake light issues. I'd truly suggest chunking them asap.

Again, the Walbro or Keihin carb is just fine. We can tune these, perhaps a small up-jetting, then you have a nice machine.

Mine has since ran some 4000 miles and hasn't missed a single beat, what a great little scooter!

Michael

PS: Great looking scooter! What 's with the paint? Looks fantastic.
Member
Et4
Joined: 05 Jul 2018
Posts: 13
Location: Lancashire
Thu Aug 23, 2018 6:55 am quote
Hi, Iíve sorted the brake light, Iím slightly embarrassed to admit this but it was a faulty bulb!!!! Lesson learnt there in future, the carb fitted to mine was the standard et4 125 keihn and it wasnít working very well, the diaphragm had a split in it so hence why I opted for the gt125 carb, itís the same type of carb just slightly bigger (see pic), it fit onto the inlet easily but I had to adapt the pipe from the airbox, everything else including auto choke fit as before

BD94EE6F-43D1-464F-B982-F93A8AFDDB05.jpeg

Hooked
ET4 187
Joined: 14 Mar 2017
Posts: 231
Location: Germany
Thu Aug 23, 2018 8:57 am quote
Hello DazzerLancs,

The carb intake is huge, compared to the original Keihin. If the old intake was used, and it was adapted, a false airflow may result. These carbs are quite sensitive to air flow, and this might be a source for erratic motor behaviour.

I agree the Keihin is in need of an overhaul.

Concerning the Air flow, even removing the air filter (the sponge) will make for false carb settings, so I do feel the new carb is causing troubles.
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