How to install piston on drr 70 quad - Quad 47 cc / 49 cc Pocket Mini Bike Scooter Atv Pull Start

Question about 1993 Achieva
2 Answers
93 oldsmobile quad 4 2.3 one piston is not working
...remove the head. It needs to be repaired, and check the piston for damage. You could also do acompression check to rule this out. you probably broke a piston ring in the #4 piston have a ...
The head needs to be removed anyway, so check for broken piston rings.

http://www.fixya.com/support/t12006246-ive_got_denon_drr_m30_keeps_poping_back
The solution from AlecBrown133 above fixed the same problem for me. The only comment that I would add is that the same repair can be done with a normal rubber band. I used one to fix the same issue with my Denon drr-m30 and it is significantly cheaper than the 10 pound option.

The solution from AlecBrown133 nails it. The only comment that I would add is that the same repair can be done with a normal rubber band. I used one to fix the same issue with my Denon drr m30 and it is significantly cheaper than the 10 pound option.

Try Curry's partmaster website.

It may be that the "missing" rams are used by your motherboards Graphics card.

The headvalve piston has 3 orings and a vinyl piston stop. The orings must be in good condition and the surface that they contact should be smooth. Look at orings and mating surface with magnify glass looking for wear or scratches. Remove scratches in head with 400 grit paper. Replace orings as needed. Some models utilize a quadring as the inner oring and should be replaced (quad ring # 910763 wears fast and causes leak) The vinyl stop should not be cracked. Parts are available at dewalt service center or www.toolpartsdirect.com. Good luck

Unfortunately it is never possible to find out the cause, it is not very common, but does happen. For this reason when doing work on the piston it is recommended to always use new circlips.
Even then it may be the installers fault, or a damaged clip, or the groove in the piston not machined exactly.

clean the pinch roller

If you have a stethoscope, listen to the injector while the vehicle is running, it could be stuck open. If you hear it pulsing the same as the rest of the injectors, then unplug it, let the engine run so it can get all of the unburned fuel out of cylinder (you said the plug was wet), take the plug and coil from cylinder number three, install them in cylinder # 4, put the coil/plug from 4 into 3, reconnect the injector, and see if the problem moves to cylinder three. Next if the problem does not move to cylinder 3, then you have an issue with either the wiring to the connector at cylinder # 4, or you have a mechanical failure. Remove the valve cover, check the valve springs on # 4. make sure they look the same as all others. If so, turn the crank and further inspect them. If they are mangled, remove the head. It needs to be repaired, and check the piston for damage. You could also do a compression check to rule this out.