Its not going to be your timing for fucks sake, do a plug chop and check your fuel settings a 125 jet still might not be enough

I have an aprilia 125 redrose cruiser its keeps burning holes thru the pistons. i have been told the timing may be out, can anyone tell me how to adjust the timing, I am on my 3rd piston in a matter of weeks i am using mitako pistons not cheap rubbish. its a rotax 123 diagram would be mch appreciated Dave

It's very unlikely the that ignition timing will have shifted. Have you modified the exhaust or airbox at all? That could make it run very weak, though I'd expect it so seize rather than hole pistons...

Before you go changing your timing, as that shouldnt have moved unless someone has moved it (infact i think its done by the CDI on your bike) have you checked the fuel mixture? could be running too lean, or maybe the spark plug is too hot check it against the manafactures spec.HTH 

HiYou could use octane booster instead, or use one of the thicker base gaskets and lower the compression. Or adjust the ignition timing to retard it a touch.The BR10EG is pretty similar to the B10EG, just the BR is a resistor plug. Using the 8 would be the one that would likely cause the most problems.All the bestKeith

Hi Not surprising it runs badly on a 145 main jet. That will flow almost twice as much fuel. I would say go up one or 2 sizes. Maybe a 115 at most. If you can then put the original airbox back on. Think there are 5 grooves on the needle so go up one. Quite likely the problem with burning a hole in the piston is a combination of just using normal unleaded (too low an octane rating) and using too hot a plug. Never seen a workshop manual for the Red Rose. You can get an engine manual from Peter Knight onhttp://www.rotax.co.uk  (shared with the AF1 Sintesi & Futura, and early RS125). I have an Italian owners handbook I can try and scan for you.Timing is a pain to do. And it would be easy to make a mess of it. You can check it with a strobe light (from memory 12 degrees btdc at 10000rpm, although very early ones had timing with no advance / retard).All the bestKeith 

HiRed Rose has a 26mm carb and should have a 108 main jet, and the needle should be an X15 with the clip on the 3rd position. Going to a 125 main jet is a big change, and should not be necessary (and unless you are running round on full throttle everywhere when it holes pistons then it is not likely to be the problem).Timing can go out. It is adjustable. The stator is mounted on 3 bolts which go through slots. Slacken these off, rotate the stator a small amount and tighten again to adjust the timing. However you will need a dial gauge to set it accuratly.Stock plug is an NGK B10EG.Remember that it probably should be running high octane petrol rather than normal unleaded. Owners handbook says "benzina super" which I think when new referred to 98 RON fuel in Italy. Using too low octane fuel could easily result in a hole burnt in a piston.All the bestKeith

Hi KickstartIt has a 26mm carb on & it had a 108 main jet, I have been using unleaded fuel, have just rebuilt the bike & moved clip on needle down to the bottom of needle put a 145 main jet in, it starts on the button ticks over erratically & has no power since adjusting carb settings needle & main jet, its got an air performance filter on so i know the main jet needs to go up, any suggesting how many sizes up from a 108 it needs to be, the timing i am going to have to take to a bike shop as I havn't a clue how to adjust that, perfectly honest I'm sick of it just costing me money all the time, pistons, gaskets, jets, trailored bk home after breaking down etc had nothing but problems with it since day one, 3 pistons later & still having probs with it.

i have modified the airbox I have put an airperformance filter on, but this was only after it had holed the 2nd piston the first piston seized the second piston holed the 3rd piston also holed, it has a pbh26 carb on with a 125 main jet it use to have a 108 jet in until i replaced it after the 2nd piston holed with a 125 jet, i have just got a pbh28 carb for it hich i will be fittin when i have repalced the piston yet again. still loking for timing settings if anyone knows were I can obtain them

HiIf you use the original airbox and filter then go back to the stock jetting. You are going to gain next to nothing from a single filter.The B10EG (not the BR10EG) is the correct standard plug.If you go for a 28mm carb then you will likely have loads more problems setting it up. Main jet would be around a 120, maybe a 125, using a 28mm carb based on what was used on the AF1s.Is your frame number in the range 01001 to 01480? If so it has the older ignition without variable timingAll the bestKeith