2005 (55) aprilia rs 125

[simmons_Scaffold]

hello 1st post here, i have just bought the above bike again after not having 1 for 13years as a project and to ride out with my dads rd400

we both love the 2stroke era, but i sadly never had my rs125 for long enough those years ago to get to know their problems!!

the one i have bought runs but......... when i bought the bike, the previous owner had blown a radiator pipe just above the head it joins the blead screw. now im not sure weather the pipe was just very weak and perished and needed replacing or the engines cooling system has failed and built up the pressure and found a weak point in this hose.

i then changed this part and re added the coolant etc ran it up to 48 degress on the dash board but the radiator was still stone cold?

which leads me to point is there a known problem with either 1.head gasket problems 2.water pump problems 3.thermostat problems?

any other help regarding these bikes would be much appreciated

[Robby]

At 48c the thermostat is nowhere near opening, that will start to happen around 75c. The rad will be cold until then.

[Kickstart]

Hi

Yep. Aprilias used a couple of different thermotats. Used a 50 (I think) degree one on the early 127 engined bikes and a 70 degree on on the later 123 and 122 engined bikes. Think both temps are available in a fitting to suit the RS so they occasionally get swapped in. But it won't open at 48 degrees.

All the best

Katy
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[P.addy]

FWIW mine was run for a very long time with no thermostat. Was ridden gently until about 60 degrees which aside from taking a little.longer, was perfectly fine.