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Post by desertman123 on Apr 9, 2016 18:09:28 GMT -5
So I inherited a 50cc with that engine in it, and I can't for the life of me get it started. It definitely looks like someone tried to repair it but failed. The oil is good, the spark plug looks new. It was missing its CDI box and the carb was dirty, so I've since dealt with those but it still doesn't start, even with starting fluid. Won't pop once, won't stumble even once. Nothing. The CDI box is AC and i confirmed theres spark with a tester. I checked the valve lash and set it (it was mostly fine but figured it didn't hurt to check) For the CDI, I got www.amazon.com/GOOFIT-Performance-Racing-Scooter-139qmb/dp/B00UBTKWY4/ref=sr_1_1?s=automotive&ie=UTF8&qid=1460243391&sr=1-1&keywords=139qmb+cdiThat. Do I need an aftermarket coil too? I was just using the stock one. The black spacer in between the carb intake boot and the intake port on the engine is missing its gaskets and causing some of the intake charge to blow out of the sides (confirmed with soap) of the spacer. Could this be causing it? It's a relatively small issue but I'm at a loss. I figured it shouldve at least popped once, since not even that much is escaping. Anyone got insight? Edit: not entirely related but the kickstarter doesnt work too well. It gets stuck often and i can basically stand on it without it moving. Other times it kicks with not too much effort. |
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Post by JerryScript on Apr 9, 2016 20:15:23 GMT -5
Fix that intake issue, that is a bigger problem than you might think. Can't say if there's other problems till that's ruled out.
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Post by powerzombie on Apr 10, 2016 5:23:58 GMT -5
An intake leak like that will cause you more problems than you can imagine!
Even if you just use some silicone or permatex gasket "maker" to seal it, you'll find it will probably run.
Then make some good gaskets.
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Post by desertman123 on Apr 10, 2016 9:42:27 GMT -5
thanks guys! I'll definitely get the gasket sorted and check back. btw rereading my original post, the carb was rebuilt, not just cleaned.
Any advice for the kickstarter? Should I just take off the cover and inspect the whole mechanism?
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Post by username on Apr 14, 2016 4:01:21 GMT -5
Yes i would, sounds like broken teeth on the gear, there only cheap to buy as a set, replace it and grease it up at the same time (careful with grease in your cvt cover)
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Post by desertman123 on Apr 17, 2016 19:14:11 GMT -5
Yes i would, sounds like broken teeth on the gear, there only cheap to buy as a set, replace it and grease it up at the same time (careful with grease in your cvt cover) Will do! I've been dealing with the engine the whole time so I haven't gotten a chance to deal with much else. Probably figured out the issue. Ran a compression test and got 0 psi so I figured might as well tear it open and see what's going on. Ended up being the intake valve stem being bent and sticking in the guide. Gonna deal with that and see if it FINALLY runs. |
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Post by desertman123 on Apr 21, 2016 18:21:32 GMT -5
Installed the new valve and ran a compression test - just around 110-120psi. It pops occasionally when I tried and firing it up but still won't start. Should I look back at the carb?
ALso the starter spins but doesn't throw the teeth out to the flywheel. Is this the starter or bendex? Or Both?
Also got that kickstarter sorted. Cleaned and greased it, works pretty decently now.
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Post by tortoise on Apr 21, 2016 19:10:42 GMT -5
Insert a probe into the spark plug hole. With piston at top-dead-center, observe if flywheel "T" timing mark is aligned. Sometimes the crankshaft woodruff key will shear . . or cam timing is off.
Test battery cranking volts.
How was this issue corrected? Replacement parts are relatively inexpensive. Use stock ignition components. |
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Post by desertman123 on Apr 21, 2016 19:51:57 GMT -5
Insert a probe into the spark plug hole. With piston at top-dead-center, observe if flywheel "T" timing mark is aligned. Sometimes the crankshaft woodruff key will shear . . or cam timing is off.
Test battery cranking volts.
How was this issue corrected? Replacement parts are relatively inexpensive. Use stock ignition components. Ill check timing and battery voltage. I ordered and installed a new spacer/gasket, fit just fine. Edit: Forgot to mention how the starter was acting exactly. I'd try and start it and it might turn the engine for a few seconds but then disengage. Other times it would never even engage. Still gonna give the battery a charge. |
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Post by JerryScript on Apr 22, 2016 2:48:36 GMT -5
What did you set your valve lash to?
How many turns out is the a/f screw? Do you have the stock air filter installed? Exhaust tight?
New plug? Is it wet after attempting to start? Does it show a good spark when pulled?
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Post by desertman123 on Apr 22, 2016 9:39:46 GMT -5
What did you set your valve lash to? How many turns out is the a/f screw? Do you have the stock air filter installed? Exhaust tight? New plug? Is it wet after attempting to start? Does it show a good spark when pulled? .004" on both sides. I think 2 turns (I'm not by the scoot right now to check). What should it be set to to start off? I just guessed. Not the stock airfilter, didn't come with it. Exhaust tight. Using the plug that came with the engine since it looks almost new. Yep it's wet, gapped to 0.025". I've checked spark with a different tester but not the spark plug itself, I'll do that. It'll pop and stumble occasionally (never enough to start) so I know there's at least some combustion. |
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Post by powerzombie on Apr 23, 2016 17:17:53 GMT -5
Open your gap a bit, to .035, on a new plug.
Blow some compressed air in there while you have the plug out, then try it again.
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