Yamaha aerox 2003 AEROX YQ won't start when pressing the srat button, rear brake light doesn't come on when lever pulled in. The start button however had been hit or miss for the last few week, kick start is jammed but thats another issue for another day, any ideas? i've taken the start switch off the right hand bar, cables seem ok, and contacts look fine, i'm lost please help!

SOURCE: i have a yamaha aerox

Clean the carburetor. Pay special attention to the jets inside the float bowl area. Remove the throttle and air screws and spray cleaner into the holes and every other hole in the body of the carb. Remount the carb then screw the throttle and air screws inward until they LIGHTLY seat. Now open each of them one and one half turns. If the bike still wants to speed up the idle on its' own, the seals and rubber fittings between the carb and the cylinder are not sealing out the outside air. New seals etc., are needed.

David Parker

• 333 Answers
• Posted on Jul 04, 2011

SOURCE: i have a yamaha aerox

You need to check if you have spark and fuel:
1: Remove spark plug and fit it back in the plug cap, crank over to check spark

2:If you have spark check to see if plug is wet or dry
(a)If dry, there is a fuel issue and you need to check by the carburettor and tank for fuel and/or any vacuum hoses not connected.
(b)If wet you might have a faulty plug or flooded in which case try starting with full throttle and no choke(if Manual choke)

3:If no spark, look for the cutout switch(normally on the right hand side handle bar) to make sure it is on and that there is no water residue on any HT leads etc.

SOURCE: i have yamaha aerox and wont start

Have you been using 2 stroke oil in the oil tank? A lot of new riders haven't had this explained. A neighbour used engine oil and has now got to strip and refurbish the engine. A 2 stroke engine mixes oil with the petrol to lubricate the crank and con rod on the induction cycle. If you use engine oil, it carbonises in the engine due to the extremely high temperatures on the underside of the piston and aroud the bearing surfaces of the crank. It will run "ok" for a short while on this oil, but will eventually kill your engine. Also on 2 strokes the exhaust system needs regular cleaning to remove "coke" which is burnt oil in the form of a sludge. 2 strokes use exhaust tuning to improve performance and efficiency, so it may need a clean. This is the best advise I can offer with the information supplied, and also the most obvious. Just one other thing - when you turn the engine over do you get a spark? It could be the coil, if the rest is good. Sorry I can't be of more assistance, I hope this give you an idea of where to go from here.

SOURCE: yamaha aerox no indicators or starter motor

Check fuses 1st & then connector blocks for dirt,corrosion & fastness

SOURCE: no fuel getting through to engine yamaha aerox

You are going to want to know if yours is fuel injected or carborated. I am pretty fairly certain it has a carb. So you are going to want to go to your gastank and follow the hose to your carborator. There is probably a spring clamp on the hose so take that off shut off your fuel valve. Now take the hose off and put the hose over something you can put gas in and turn on the fuel shut off valve. If gas comes out freely then its your carb if it doesnt its your shut off valve and quite probably you carb. You will then just need to clean them thoughlly and check them again after you get them back together . if it is the shut off valve check it again first before you rip the carb apart. if its fuel injected which i dont think it is email and i will walk you through that.
A.J. Weaver