50cc cranks, starts, idles well for 30 seconds, then dies.
by: jbrukardt - Jun 23, 2014 8:19:46 GMT -6
Post by jbrukardt on Jun 23, 2014 8:19:46 GMT -6
Good morning gentlemen,
Building off this previous thread which unfortunately turns out to be ancient, im still having problems with a 50cc I got for a friend of mine. But I feel as if im making progress.
old thread for background info: scooterdoc.proboards.com/thread/9410/problem-scooter-stay-running-start
Summary:
Heres what it is:
2011 Puma Romeo 50cc in seemingly good shape, 700ish miles on it, with a 50cc taotao engine swapped into it (prev owner said engines were identical)
Heres what it does:
1) Starts fairly clean, idles well for 30 seconds, then conks out
2) once it conks out, absolutely will not start at all without a 20 minute wait. Then back to step 1
3) the minute you put any throttle into it, it dies during that 30 seconds it does run.
Plan of attack:
1) Check for vacuum problems, im actually heavily leaning towards this being it. The previous owner said he "messed with the airbox" and it seemed to be better). Any guides out there for testing vac? I saw something about spraying propellant down the vac line. Problem is, my lines look quite different from the standard diagrams.. and i seem to be missing some. Pictures below
2) Check for loose wires coming from the CDI - DONE, ALL WIRES LOOK GOOD
3) Clean the carb - DONE, not dirty at all
4) Adjust the carb (including checking if the butterfly valve covers the pilot outlets) - DONE, SEEMS TO BE ADJUSTED WELL
5) Theres something about a gasket/spacer on the intake manifold that goes bad, any details on that ya'll can give me an idea on?
6) check out the enricher, make sure thats working right (watched a few videos)
7) and most importantly, most also most in depth, set the valves. This procedure i can do in my sleep from my other small engine experience - DONE, im amazed it started at all, valves were so tight i couldnt fit a .001 in there, adjusted both to .004. Now it idles very strong (no tapping though) and feels good for that 30 seconds.
Ok, now for what i think... think, might be the problem. Something is very odd with the vacuum system. The lines dont go where i expect, and one line seems to be entirely missing/cut.
Pictures of the carb and tubing
^^ theres this tube nipple that comes off the exhaust and goes... nowhere? Theres no tube on it, never has been
and then theres this, a tube that comes out of the carb, and appear to be cut: the one right to the left of tube going to the fuel filter.
Looking at this diagram, i cant even find my "pair system"
I do have a connected tube going to both the crankcase breather, and the s-tube area though.
Building off this previous thread which unfortunately turns out to be ancient, im still having problems with a 50cc I got for a friend of mine. But I feel as if im making progress.
old thread for background info: scooterdoc.proboards.com/thread/9410/problem-scooter-stay-running-start
Summary:
Heres what it is:
2011 Puma Romeo 50cc in seemingly good shape, 700ish miles on it, with a 50cc taotao engine swapped into it (prev owner said engines were identical)
Heres what it does:
1) Starts fairly clean, idles well for 30 seconds, then conks out
2) once it conks out, absolutely will not start at all without a 20 minute wait. Then back to step 1
3) the minute you put any throttle into it, it dies during that 30 seconds it does run.
Plan of attack:
1) Check for vacuum problems, im actually heavily leaning towards this being it. The previous owner said he "messed with the airbox" and it seemed to be better). Any guides out there for testing vac? I saw something about spraying propellant down the vac line. Problem is, my lines look quite different from the standard diagrams.. and i seem to be missing some. Pictures below
2) Check for loose wires coming from the CDI - DONE, ALL WIRES LOOK GOOD
3) Clean the carb - DONE, not dirty at all
4) Adjust the carb (including checking if the butterfly valve covers the pilot outlets) - DONE, SEEMS TO BE ADJUSTED WELL
5) Theres something about a gasket/spacer on the intake manifold that goes bad, any details on that ya'll can give me an idea on?
6) check out the enricher, make sure thats working right (watched a few videos)
7) and most importantly, most also most in depth, set the valves. This procedure i can do in my sleep from my other small engine experience - DONE, im amazed it started at all, valves were so tight i couldnt fit a .001 in there, adjusted both to .004. Now it idles very strong (no tapping though) and feels good for that 30 seconds.
Ok, now for what i think... think, might be the problem. Something is very odd with the vacuum system. The lines dont go where i expect, and one line seems to be entirely missing/cut.
Pictures of the carb and tubing
^^ theres this tube nipple that comes off the exhaust and goes... nowhere? Theres no tube on it, never has been
and then theres this, a tube that comes out of the carb, and appear to be cut: the one right to the left of tube going to the fuel filter.
Looking at this diagram, i cant even find my "pair system"
I do have a connected tube going to both the crankcase breather, and the s-tube area though.
..BAD TO THE BONE..
