Minarelli Oil Injection Pump Adjustment & Bleeding
Nov 24, 2011 20:40:40 GMT -5
jdl357 and carlosrp like this
Post by usmcdoc on Nov 24, 2011 20:40:40 GMT -5
Just came to my attention while putting a big bore kit on my 2010 Jonway Wasp today.....over the summer I looked at 3 Minarelli based scoots for peeps that complained of 'soft seizing' One replaced his clone Mikuni oil pump...with a real Mikuni....and still soft seized. Go check your oil pump as most do not know that they can be adjusted...and MUST be adjusted for proper flow...at idle you are getting about 120:1 mix...and as high as 20:1 at about 9-10,000 rpm.(if it is adjusted properly!). Very few are set correctly from the factory and cause problems. This is ESPECIALLY important if you install a BBK for your neighborhood street burner. Some remove the pump and premix which at 50:1 is ok at mid speeds.....but loads the engine at idle fouling plugs.....plugging the exhaust....and causing high carbon build up.
Remove the right fan shroud....lay on the ground and have a look. You will see a mark on the pump cam...(where the cable attaches...it is on the bottom of that cam..and another on the engine block) At closed throttle these should line up. There is a 'cam stopper' as you will see to stop it from going too far backwards...and most used that for the idle setting...which is wrong and means at high rpm you are running lean on oil. On the cable you will see a barrel nut such as on your handgrip throttle cable for your carb. Use that to adjust and align the marks. I set mine a bit beyond that for a safety margin. I set them all a tad bit past the alignment marks for them...and not ONE more soft seize from their scoots! as it allows slightly more oil at top speed runs. Go check yours....chances are it is simply resting on the cam stop at idle....which is about 5-7 mm behind where it should be. Lastly I saw many 2 strokes ruined because they ran out of oil....refilled it and drove off.....not knowing the oil pump MUST be bled by that tiny bleeder screw...as an oil pump is designed to pump oil..not air....just like our brake systems. So take a look at yours...comment back to us...and report back what you find....you will be surprised at how many lean runs you've already done! Chinese make some very fine scoots....but at times they lack in attention to detail and QC... :2cents:
Remove the right fan shroud....lay on the ground and have a look. You will see a mark on the pump cam...(where the cable attaches...it is on the bottom of that cam..and another on the engine block) At closed throttle these should line up. There is a 'cam stopper' as you will see to stop it from going too far backwards...and most used that for the idle setting...which is wrong and means at high rpm you are running lean on oil. On the cable you will see a barrel nut such as on your handgrip throttle cable for your carb. Use that to adjust and align the marks. I set mine a bit beyond that for a safety margin. I set them all a tad bit past the alignment marks for them...and not ONE more soft seize from their scoots! as it allows slightly more oil at top speed runs. Go check yours....chances are it is simply resting on the cam stop at idle....which is about 5-7 mm behind where it should be. Lastly I saw many 2 strokes ruined because they ran out of oil....refilled it and drove off.....not knowing the oil pump MUST be bled by that tiny bleeder screw...as an oil pump is designed to pump oil..not air....just like our brake systems. So take a look at yours...comment back to us...and report back what you find....you will be surprised at how many lean runs you've already done! Chinese make some very fine scoots....but at times they lack in attention to detail and QC... :2cents:
