Pics oil pump. Must it be replaced?

4 replies to this topic
  • michaeltaz

Posted December 21, 2009 - 04:03 AM


I bough this bike and got lots of sand in oiltank. How critical is this damage on the rotors of the pump? Must I replace complete housing with rotors?

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  • zbbt

Posted December 21, 2009 - 04:14 AM


the oil pump would be the least of my worries. how does the cams and piston look? and yes both the rotor and its outer housing must

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  • Wes Woodin

Posted December 21, 2009 - 07:31 AM


I would definitely check the internals of the engine. I would hate to replace the oil pump and housing then have other failures. Check the piston, cylinder, cams, ect. How many hour were on the bike. Drop the carb too.

  • grayracer513

Posted December 21, 2009 - 07:58 AM


The damage to the lobes of the rotors isn't terribly bad here, but the scoring on the sides makes me a bit uncomfortable. I would replace the feed pump assembly (the housing/rotor/end plate/gear assembly) and reuse the return pump (the wider of the two rotor sets). It is in better condition, and operates at very low pressures. Be sure to use a new drive pin for the return pump (inner, larger rotor)

  • michaeltaz

Posted December 22, 2009 - 01:16 AM


Thanx for all the info. The piston, silinder and top (head and valves) are fine. I will replace the piston, rings and timing chain just to be safe. The engine had been abused by previous owner. No oil change for 2 years and running with torn air filter. Carb was full of sand. The frame oil tank had about 150ml sludge, aluminium paste and sand in it. This paste was also between clutch plates. I was just uncertain about the oil pump. I am new to the high performance four strokes and am just worried because I know how critical the oil flow and pressure is for these mini F1 engines.

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