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Post by soulraver on Jan 3, 2023 22:01:04 GMT -5
I have a buddy 50, worked great, I needed more power (live uphill) and got the 70cc kit. Followed directions, but no where did it say i needed a shorter spark plug, so the piston hit my old plug, not hard, but enough to bend the top electrode, just bent it didn't break off. I replaced the plug with the right one, checked everything and it seemed fine.
Fired it up, ran for about 3 min, and made a pinging noise and died, wont start. I take it apart and i find the first piston like this and the head.
I clean out everything, get a new piston, new head, start again, same issue, as per the second piston in the picture. So i take everything off, clean up the old parts from the 50cc, put on the cylinder body and piston, double checked everything, started it up, ran for 4 min, same exact issue.
I'm at a complete loss. The 70cc kit i got is not a cheap one, I paid $260 online for the full kit. Do I need to take the whole engine apart? Is there something obvious i'm missing here?
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Post by aeroxbud on Jan 4, 2023 4:47:25 GMT -5
It looks like you still have debris left in the bottom end. If you are lucky, the crank might be okay. But the only way to be sure, is a strip down.
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Post by soulraver on Jan 5, 2023 2:21:18 GMT -5
Dang i was hoping that was not the case, seems like a lot of work. Okay thank you for the reply!
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Post by aeroxbud on Jan 5, 2023 6:11:44 GMT -5
It's a pain to do. But it's better to be sure than buy a new cylinder and it end up being toast again.
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Post by 90GTVert on Jan 5, 2023 6:28:36 GMT -5
I've been there before. It sucks. It's easy to miss something in the crankcase or exhaust. Even a piece of debris in the pipe can make it's way back in and bang around in there. Also from having so many things go wrong and chew up pistons and cylinders, I don't reuse circlips if they're removed (keep spares around at all times... they're cheap) and I try to replace the wrist pin bearing most times that the engine is apart. At very least, give that a good inspection and if there is any question at all of time it's been used or it's condition, replace it. Small, relatively inexpensive, parts can cause big headaches and big expense.
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Post by jackrides on Jan 6, 2023 17:06:11 GMT -5
How many miles on it? Before a complete disassembly try removing the engine, head, cylinder. Remove the intake manifold and exhaust and shake them out. Support the rod so it doesn't slap the engine case, turn it upside down and shake it good real good. (Music may help) If nothing comes out spray a little solvent into the case, slosh around and try again. All 3 bearings must be oiled after this! (2 stroke oil). At each removal, watch carefully for tiny pieces. Oh yeah, check the piston to see if both circlips are in place. Let us know.
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Post by 90GTVert on Jan 7, 2023 0:54:16 GMT -5
I've used kerosene and a transfer pump to flush my cases without total disassembly. Put the engine so the crankcase opening faced down some sitting over a catch pan and used a battery powered transfer pump to pump kerosene through from the reed area and from all around the cylinder opening. I was very liberal with the kerosene, but I cleaned the catch pan prior so I was not really losing/wasting kerosene. Still used it in my heaters later without issue. Not sure if that's perfectly acceptable, but it worked. Can pour through a filter just to be sure there are no chunks in there. Some people use gasoline for this... I think I have done that as well. In that case, it wouldn't go back in my scoot just for total safety. I worry much more about any debris in a moving engine vs in a heater that's just wicking up kerosene to burn.
I let it drip dry a bit and then used compressed air. I think that's about as good as it gets for the cases without a total disassembly.
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Post by Lucass2T on Jan 7, 2023 11:40:22 GMT -5
I've used kerosene and a transfer pump to flush my cases without total disassembly. Put the engine so the crankcase opening faced down some sitting over a catch pan and used a battery powered transfer pump to pump kerosene through from the reed area and from all around the cylinder opening. I was very liberal with the kerosene, but I cleaned the catch pan prior so I was not really losing/wasting kerosene. Still used it in my heaters later without issue. Not sure if that's perfectly acceptable, but it worked. Can pour through a filter just to be sure there are no chunks in there. Some people use gasoline for this... I think I have done that as well. In that case, it wouldn't go back in my scoot just for total safety. I worry much more about any debris in a moving engine vs in a heater that's just wicking up kerosene to burn. I let it drip dry a bit and then used compressed air. I think that's about as good as it gets for the cases without a total disassembly. Id say rather use diesel because of fire and fuel vapor hazard. Gasoline is a great detergent tho!
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