Speedfight 2 Upjetting

Hello, Okay the speedfight 2 stock jet is about 52, it was then upjetted to 56 by the shop when they derestricted it.
Then I brought the bike and I put an Giannelli Reverse pipe on, malossi variator kit, malossi red foam, and 6gr rollers.

Now I looked at my haynes manual and changing jets looks like a bit of a big job for me and I normally break things. So I am going to take it to the shop and tell them to change the jet, what size jet should I tell them to install?

Hasn't been upjetted since the deresticted(read top of post).


Thank you!
Rick.


P.S: Example of me breaking things, I have unthreaded every thread but 1 on my tranny case :w00t: Cable tires for the win hehe.

 

I'd buy a tapping kit and re-thread your cases bud, you wouldnt want your tranny case falling off at 40 mph would you?

 

Thanks but that didn't really help answer my question, I clicked here in excitement of a jet size

 

if your taking it to a shop then wouldn't they be able to suss out what jet size is needed? i mean, its like 30-40 quid for an hours labour, least they could do is work that out? doesn't take that much effort for to get to the jet in the carb, i watched a mate do it.. like 4 screws in total =\

(i wouldn't do it personally like, i'd probs break the carb but then again thats me)

 

Okay, well I just thought my bike would benefit from it because its only got 56, were as all my mates have 70-80's..

 

If your peds running fine (check the plug colour) then dont upjet.

52 is standard, 58 should be fine for the setup. but check the plug its the only real way of knowing

oh and, just because your friends may have bigger size jets, doesn't mean you should have, upjetting wont make it faster, unless its the wrong jet size to start with.

 

best way to know really is to check the plug....if its wet (oily or a damp black) then ur setup has to much fuel in the ratio but you can compensate for it with the air/mixture screw, just keep winding the plug out untill you get a descent texture on it, and btw if its sooty then theres not enough fuel

 

No mate, sooty would be rich i.e too much fuel not enough air...

Also the mixture screw only controls idle mix.


@OP Find out the condition of your plug, with a pic perhaps and we can see how shes doing.

 

The plug is 1 month old.

 

yeah well done, now take a picture of the part of the plug we need to see arc:

And the tranny case bolts are notorious for stripping the threads in the case on
speedfight engines....

i stripped a couple on my old speedfight with relative ease :msn1:

 

woops! Well the other end is just as clean as it was when new.

 

:w00t: :w00t: :w00t: :w00t: :w00t: :w00t: :w00t: :w00t: :w00t: :w00t:

 

Minor, whats the cure for this?. The plug I took fron the lads 70 zip sp looks the same with the centre pin hardly visible

Is this coz its running lean or a cooler plug needed?
TY

 

Other end:

Hot => lean => bigger jets?

 

not the other end!

:msn1:


the end that goes in the cylinder but a better one so can see further down the plug

 

Lmao, okay well I'm sort of new to this and have no idea what you ment before. I will get another photo soon

 

ok no worries

 

The electrode is an iridium, they are very thin on the end from new,
it lowers the arc over voltage....

 

i used a 74main jet on my 50 wen i had a technigas. and if u look under ur seat left hand side theres ur air intake if u get that off and look down it theres 2 small holes. i bored them out as big as i cud. and it ran just right did the plug. :bird: .