Rough Running so plug chop done - what next

[HoggyF]

Been trying to sort the bogging down on my sones pit bike so carried out a plug chop yesterday, full throttle up a lane through the gears and the result was
https://i541.photobucket.com/albums/gg365/HoggyF/IMAG0298.jpg
The original problem was that it bogs down when you open the throttle fully open from tickover I.e. a big blip, other than that it rides quite nicely but it did feel aq little bit weak at the top of the revs.
Engine is brand new but carb is off the old engine and we don't know the spec of either engine so it is quite likely that the new one could have different size valves etc.

I think the plug looks a little bit rich but previous advice with it bogging down was that it would be the pilot jet???

What to try next??

[MarJay]

Letting us know what sort of bike it is might be a good start!
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Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

[neil.]

Looks lean to me - white ceramic bit.

[HoggyF]

Bike is a pit bike with Loncin 125 engine

plug is brand new so that probably explains the white bit, the circular end of the threaded section is quite sooty to my mind and not the nice coffec colour I had hoped for.

[temeluchus]

Its the condition and colour of the tip your interested in. It does look lean as the tip is rather shiny and white.

Rich running or over oiling would make the whole lot black and sooty.
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[hazza]

Running Lean would also explain the bogging from tick-over to full throttle.
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3 Honda NC50's(Sold)-->'72 Puch Maxi S (Sold, want it back!)--> '90 Yamaha RXS 100 (Stolen)--> '87 Honda Cub 90(Sold) --> '95 Kawasaki Eliminator (Sold) --> '98 Bandit 600 (Sold) -->'07 SV650S (Current)

[HoggyF]

So if its running lean does that mean adjusting the needle or going up a size on the main jet.

Anyone know where to get jets for a TaoTao pitbike carb?

I remember from yrs ago a car engine tuner used to drill out his jets or solder them up then re-drill, anyone tried this?

[hazza]

I would start with jets first. I once brought a carb off a thumpstar pit bike to fit on my C90, i couldnt find any different size jets so i still have that carb now, although the c90 is long gone. They seem to be difficult (at the time anyway) to get hold of. I wouldnt recommend soldering/drilling out jets. They are precision pieces of kit and id be suprised if you had any success at all with this method.

As for sourcing jets, Ebay is probably your best bet mate
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3 Honda NC50's(Sold)-->'72 Puch Maxi S (Sold, want it back!)--> '90 Yamaha RXS 100 (Stolen)--> '87 Honda Cub 90(Sold) --> '95 Kawasaki Eliminator (Sold) --> '98 Bandit 600 (Sold) -->'07 SV650S (Current)

[P.]

Adjust the mixture screw first, I'd be doing that before rejetting.

Could just be the wrong mixture...but does look overly lean, I wouldnt be happy running on that at all..

[HoggyF]

Tried mixture screw, doesn't make much difference although it gets slightly less "boggy" as you get nearly all the way in then another slight turn and it starts to die.

[temeluchus]

[HoggyF]