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Post by lain on Jun 15, 2015 11:35:29 GMT -5
rcq92130 I would if I knew how to weld and had the money for it. So everything seems good again now after finishing everything. Rehoned the cylinder, put new rings on the piston, put a head on with less miles that looks better, put it all back together and it definitely feels stronger and smoother, and ontop of that quieter! I feel the high end is lacking and the high end revs aren't being used to the full potential but I believe I'll experiment with weights and figure it out, plus I plan to get better final gears, but the engine issues are gone now. Oh and no more oil consumption issue  R u running hih rpms at top end ? If your weijts are too light you will have high rpms but it will feel really weak . that is at top end Yeah it does, I'm using 8g weights. I have to wait a few weeks until I can afford anything though. The low and mid ranges work great, and I normally do not need to go faster than 40-45 and I can achieve those speeds again now without issues or weird noises. I just feel the high end could have more power, it doesn't sound like it is going faster than maybe 6k rpm at the top, I remember how it used to sound when it would get to 7.5k, the engine sounds lower than that. |
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Post by lain on Jun 15, 2015 11:12:25 GMT -5
rcq92130 I would if I knew how to weld and had the money for it. So everything seems good again now after finishing everything. Rehoned the cylinder, put new rings on the piston, put a head on with less miles that looks better, put it all back together and it definitely feels stronger and smoother, and ontop of that quieter! I feel the high end is lacking and the high end revs aren't being used to the full potential but I believe I'll experiment with weights and figure it out, plus I plan to get better final gears, but the engine issues are gone now. Oh and no more oil consumption issue
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Post by lain on Jun 15, 2015 9:37:21 GMT -5
The pumps should turn off when the end of the nozzle become submerged. If you have the gas filler guard you will obviously be unable to put the nozzle into the hole because the guard stops it right at the opening, and therefor the pumps automatic shutoff may not be effective or work at all.
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Post by lain on Jun 15, 2015 9:33:04 GMT -5
A lot of people are not informed enough and just dump oil and gas in the sink or outside. BAD! I know a lot of people who do this. I personally put old oil and gas into old oil and cleaning spray containers then once I have enough I drop them off at a local plant.
What do you guys do?
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Post by lain on Jun 15, 2015 0:52:05 GMT -5
If you don't have a spare get duct tape and get creative. Just for a test ride, nothing else, order a new one ASAP lol.
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Post by lain on Jun 15, 2015 0:03:49 GMT -5
Stop and go adds to the stress on most parts in any air cooled scooter, though it won't be fast enough to not catch it and you will most likely service the pads and bell a few times at least before it is worn too much. The belt suffers the most in stop and go slow traffic, especially when it is hot out.
I had a clutch I put in over 20k miles on, the bearings wore out before the shoes which can be transferred if I ever need them. Keep all old parts, you'll find them useful for seeing how things work without removing current parts, plus they can be salvaged or cleaned and used some more.
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Post by lain on Jun 14, 2015 22:58:14 GMT -5
Hey guys. Thanks for all your help. I ended up purchasing a new carb. My scooter ran great....until yesterday when I filled the tank 3/4 of the way up. Now it won't start at all. I'm getting a clean spark and it initially started up just fine but bogged out as soon as I took off. I didn't have a vent hose (the port nearest the diaphragm and needle cap) before and it was totally fine....now there is fuel coming out of that port when I turn the engine over. I am absolutely clueless and honestly a but frustrated that filling up on gas caused an issue like this. Do you guys have any idea what might be my problem? By the way, when I throw a vent hose on there, it doesn't fill up with gas and the engine still doesn't turn over correction* it does turn over but does not start If you didn't clean your tank you might want to do that. You said it sat for a year, then you had carb issues, then the new carb is having issues, I suspect the fuel has been contaminated or the petcock may have gunk in it. Try starting without the gas cap though, make sure it isn't vacuum related. |
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Post by lain on Jun 14, 2015 15:03:48 GMT -5
Yeah I was thinking of putting sealant on it this time because last time I didn't and this happened. I'm thinking of just "wetting" the paper with the sealant except for around the oil passage, instead I will just wet the outtermost edges of the gasket around the oil passage, but not the edges where the oil travels, the edges close to the outside of the engine. Can't remember which of the thousands of engines you have been playing with, but if THIS one is one that had significant blow-by .... and you didn't have an adequate crankcase vent ..... then it's possible that pressure built up high enough in the CC to gradually push the gasket out. One would think the torque of the head bolts would be enough, but remember the torque on these mouse fart engines is like 1 pinky ounce. This is that old blowby engine, my first engine, I' going back this time trying to fix things and get it so I don't have to open it up again. This engine does not have a crankcase vent, it has a valve cover vent, which I assume are different. |
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Post by lain on Jun 14, 2015 13:27:16 GMT -5
What about if I do not remove the circlips? Then I could just put the new rings on the piston and not worry about the clips right? I have a small cylinder hone, used it once before. I think the rods may have been torqued too many times, they seem longer, like by a few hairs, than on my other 139qmb engines. How do I go about removing them? Can I use the rods out of another engine? I'm really trying to work with what I have without buying anything else. You cannot replace the paper gasket w/o removing the jug. BTW - you might remember I've been troubled by a leak at that same spot because of a paper gasket that slipped out. Torque was not low, so that's not the cause. Many advise AGAINST using any gasket sealant b/c of the risk of clogging the oil passage .... this past time I went w/o sealant and ended up with a slipped-out gasket. May not be cause and effect, but I'm suspicious and will NOT again try no sealant. If you do the same, just make sure you only "wet" the gasket (both sides), not leave enough sealant that once the assembly is torqued it will squeeze out into places where seamant is not wanted. Yeah I was thinking of putting sealant on it this time because last time I didn't and this happened. I'm thinking of just "wetting" the paper with the sealant except for around the oil passage, instead I will just wet the outtermost edges of the gasket around the oil passage, but not the edges where the oil travels, the edges close to the outside of the engine. |
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Post by lain on Jun 14, 2015 11:33:48 GMT -5
Holysh&7 my exhaust valve is completely covered in a thick caking of something very white. The intake looks fine.
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Post by lain on Jun 14, 2015 8:07:50 GMT -5
I used gear oil for honing and seafoam after cleaning it with soap and water to remove any water/soap from the crosshatches last time, you think that's good? Or should I use light oil because it's a hot config?
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Post by lain on Jun 14, 2015 7:45:42 GMT -5
What about if I do not remove the circlips? Then I could just put the new rings on the piston and not worry about the clips right? I have a small cylinder hone, used it once before.
I think the rods may have been torqued too many times, they seem longer, like by a few hairs, than on my other 139qmb engines. How do I go about removing them? Can I use the rods out of another engine?
I'm really trying to work with what I have without buying anything else.
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Post by lain on Jun 13, 2015 22:00:53 GMT -5
Never Ever Reuse the Circlips! I don't care if you've done it in the past, just done do it again And when you replace, the opened end needs to be at 12 and 6 O'Clock. No, just because you removed the piston doesn't mean you have to replace the ring and hone. Just because you removed the Piston doesn't mean you have to Hone. If you remove the Rings may be another issue. I can't see your cylinder so I can't make a recommendation on it. A Ball/Dingleberry Hone. or I prefer A Nylon Soft Hone Brush. This is the Hot setup. Do not want to remove any material just break the glaze and put a slight Cross hatch pattern. Best Of Luck! I have never reused the G clips before, good to know it's not good before trying. I'm a little confused, everyone says to rehone and get new rings. I actually have a set I forgot I purchased extra a long time ago so I might just do it anyways. I've reused entire topends including gaskets before with pure stock 50ccs and have no issues so far, I tried to reuse a gasket once with this engine though (this is a 139qmb with a 50mm BBK) and it didn't work for even an hour. My guess is higher cc bores require TLC. |
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Post by lain on Jun 13, 2015 21:05:47 GMT -5
Something similar happened before. There was debris between the base and head when I installed the BBK the first time. It soon caused holes to appear, but this is different. This time instead of having holes my gaskets got out of between the blocks... Vibration?
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Post by lain on Jun 13, 2015 17:38:43 GMT -5
Finally got to checking this scoot. I took the shroud off and immediately found the cause of the loss of compression. It seems the paper base head gasket had somehow pushed out of the engine and is sitting around the base in pieces, the top head gasket had some pieces blown out but not nearly as bad. I have no idea what caused this but I know this is why my engine has low compression.
I'm going to replace the gaskets. If I never take the piston out of the jug then I will not have to rehone and get new rings right? I'm thinking of just clipping the piston to the skirt and removing the piston G clips.
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