Cold weather effect on performance??????

[H,POOL GADGE]

that's coz your educated and am common as muck arn 'a!!!

[philhnottm]

Will Do plug checks over next two days and also up jet and hope the cold weather is hear for a while as scooter runs great !!

Gadge and all thanks for advice !!

Although GPS's break your heart so maybe I shouldn't be to unhappy with my daily runner if it sits around 65 Gadge speed !!

[santacama]

Looks like you are a little rich for hot weather and ok for cold, but need to check the main any way.

[Jack221]

Reading this just reminds us all how delicate 2 stroke jetting is, takes forever to get right and then goes and changes with the weather
As already said, the closer you get to perfect jetting, the closer you get to a hole in the piston when the weather turns colder!
To get the jetting right it is how you read the plug that makes all the differance. Correct jetting on a 2 stroke is where the plug is running chocolate brown up to half way up the insulator, then to beige and white right on the very tip. For most guys running this lean is not safe enough (me included!) but it certainly is the most powerful jetting!

[ducksta]

Harry Barlow built me a motor couple of years agoe asked me what i was using it for i mentioned i was going into europe he then asked about route etc as the jetting would need changing when i got there diff air temp+altitude he went right into it but he had the rep of his engine to think about

[philhnottm]

Just gone from a 122 main jet to 132 main jet on 28ml Delortto.

Appeared to run better in forth at last 1/4 of throttle. No bogging in forth at all.

checked plug -now only just a slightly darker Brown than the very light that I had when running the 122.

Now a galaxy chocolate brown

However its was between 9-12 degrees so a lot warmer

[Jack221]

132 is much more like where you should be on a 210. With any needle carb at least 2 plug chops is best. One at full throttle and one holding at half throttle. It is easily possible to be running fine at wide open yet lean at half throttle. Often dramatically evident when riding flat out for a good long thrash and going great, then roll off the throttle and it heat siezes out of nowhere!
If the plug is all completely chocolate brown then its just a little too rich. If you post a picture of your plug looking down the insulator we will all comment?

[philhnottm]

Jack221

Thanks for above. The plug is darker on the bit in the middle and a lighter brown on the metal piece that goes over the middle of the plug at the top if this makes sense.
I ordered a MB BGM box pipe yesterday which should be landing early next week , having new rings put on so might take it straight to local dyno for confirmation of set up.

Guessing that I should start at 132 with new pipe ??

Phil

[santacama]

The BGM will let the engine rev a little more then the SIP ROAD, so probably you will need to up jet.

[Jack221]

Sounds like you are a little rich already but start with a 138 on the new pipe. Nothing bad happens when the jet is too big! Although you will probably end up about the same.
When looking at the plug to see the mixture you only need to look at the insulator (white cone). What I look for when the mixture is near correct for me (running slightly rich), deep in the plug it at the bottom of the white cone it will be chocolate coloured then half way up the cone chocolate will change to white. The shoulder/tip of the white cone will be milky coffee coloured. As said in this thread this time of year is best for jetting, so get yer thermals on!

I do like the reports about the box pipe. I might get one for my standard PX. You got a link for mail order?