Scooterotica

So i built a new engine and did a test drive - just a couple of miles at low revs.
Checked the plug colour and thought it looked a bit too white for safety
Up'ed the pilot jet from 45 to 55 and did another test - does not look alot different

Whats the normal range for pilot jet?

Its a SR175 with some tuning. 25mm Dellorto.

https://issuu.com/scooter-center.com/do ... a-2007_e/8

Worth downloading and keeping for future reference... Page 72 onwards deals with setting up your carb and what jets etc are at play and when.

Check the basics first too... have you got an airleak somewhere?

Oh sorry, forgot to say. I pressure tested it before fitting the engine so should be fine. I will revisit this test if I cant get it sorted by adjusting the jetting but as its only done 8 miles as test runs since being built it should be fine.

Thanks for the resource - I will read through see if it gives me any ideas

Hi, I built a friends 175 kitted Li a few years back fitted wit 25 PHBL carb with the following settings;
MJ98, p 51, Atomiser AQ266, Needle D22 2nd clip. this was setup on the dyno with an AF clubman exhaust and no airfilter.
Hope this helps. Andy

Thanks Andy. Always useful to have a reference. Reading through the info provided Formanbob I've not considered needle and clip adjustment as yet so I will have a play with that when I get a chance.

So a couple of questions

1. are needles interchangeable between phbh and phbh? The Scooter Centre doc suggests that they are not but I wanted to check I understand it correctly.
2. The scooter centre document has a diagram to aid in needle identification. It shows points A and B and measurement C on the needle. I dont see any way of working out where point A is so I assume you just measure the bottom tip - as these are all unique - in which case I have a D29
3. Clips settings. When people say second clip, is that from the top or the bottom of the needle? Mine is second from top.