TNG Venice power mystery

[carasdad]

Originally Posted by ScooterBleu

My 2006 TNG Venice starts fine runs up to 10 mph or so then loses power. We have tried and checked everything short of the muffler clog. Looking at that tomorrow. All lines operative. Compression 150. Pure gas. new Mikuni carb. new petcock. all spartkplugs are fouled, oily and black-gone through four. Help!

If you have a 2006 TNG Venice..it should be a 2 stroke engine. Do you premix or use the oil pump? It sounds way too rich..so either the main jet is too large..or if premixing you are mixing too much oil. Most premix at 32:1..which is 4 oz oil to a gallon of gas. I would also check for a weak spark as this will not allow proper combustion and foul plugs quickly. I just had that with a customers Scoot. It would spark but the spark was yellow/orange vice blue. It just kept fouling plugs left and right and had no power. Another thing is..if you used to have a Leader...TK or QJ carb then replaced it with the Mikuni...although the same size carb..the Mikuni prefers different jet sizes than the 'clone' carbs do..so chances are you may be running way rich.. What size jet are you using..and is this a big bore engine or stock 50cc?.. Let us know and we can go from there..