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Post by humancost on Aug 4, 2018 1:21:30 GMT -5
Title
2015 BMS Federal 50 won't start
2200 miles on it
Recent oil change (100 miles ago)
Driven regularly since spring
Has spark
Has gas
Carb is clean af
Fuel is running
I did the valves
Has vacuum
I drove it about 25 miles in one go, it had trouble starting when I got on it to drive home. Got it started eventually. Got gas on the way home. Scooter started fine at the gas station. Got it home and tried to start it a few hours later. But it's been dead since.
Help please
Thanks in advance
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Post by gsx600racer on Aug 4, 2018 2:30:04 GMT -5
 I want to say contaminated fuel. Seems the problem started after you got gas. 
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Post by GrumpyUnk on Aug 6, 2018 10:29:01 GMT -5
Kick start or electric? Check the grounds and other connections. 99% of these machines have 'semi-reliable' wiring. You can be semi-sure it won't be reliable.
Get some 'starting ether' and give a snort into the air cleaner. Kick it over to see if it will 'pop'. If it will, check the carb & fuel again. If it won't pop, check the spark and valves again.
tom
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Post by jackrides on Aug 6, 2018 11:24:20 GMT -5
It has spark, ok. Remove the spark plug and see if it is ok. If so, sheared flywheel key?
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Post by humanshield on Aug 6, 2018 12:03:00 GMT -5
The most likely solution is usually also the most obvious. Was working fine, you got gas, got home, stopped working. GSX600Racer's solution is the most obvious and should be thoroughly investigated before changing anything else imo.
All it takes is a thimbleful amount of water in the fuel. Seen it happen umpteen times.
You didn't accidentally fill it with Diesel or E85 did you? (just askin....sure ya didn't)
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Post by humancost on Aug 6, 2018 12:36:06 GMT -5
 I want to say contaminated fuel. Seems the problem started after you got gas.  I drove 25 miles after getting gas. The tank was nearly empty when I filled it that time. It ran fine for those 25 miles. |
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Post by humancost on Aug 6, 2018 12:37:20 GMT -5
Kick start or electric? Check the grounds and other connections. 99% of these machines have 'semi-reliable' wiring. You can be semi-sure it won't be reliable. Get some 'starting ether' and give a snort into the air cleaner. Kick it over to see if it will 'pop'. If it will, check the carb & fuel again. If it won't pop, check the spark and valves again. tom Both the kickstart and the electric start fail to get the engine started. The kickstart feels like there's no resistance on it. |
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Post by humancost on Aug 6, 2018 12:38:19 GMT -5
It has spark, ok. Remove the spark plug and see if it is ok. If so, sheared flywheel key? Spark plug is brand new. What is the flywheel key? How do I check to see if it's sheared? |
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Post by humancost on Aug 6, 2018 12:39:29 GMT -5
The most likely solution is usually also the most obvious. Was working fine, you got gas, got home, stopped working. GSX600Racer's solution is the most obvious and should be thoroughly investigated before changing anything else imo.
All it takes is a thimbleful amount of water in the fuel. Seen it happen umpteen times.
You didn't accidentally fill it with Diesel or E85 did you? (just askin....sure ya didn't)
91 Octane at a Mobil 76. You saying I should just drain and refill the gas tank? |
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Moat
Scoot Member
Posts: 88
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Post by Moat on Aug 6, 2018 20:22:28 GMT -5
The kickstart feels like there's no resistance on it. Well, there ya' go - that tells us it's most likely a low-compression issue. For now, focus on that... just how low, what's the cause, how to correct it, etc. Bob |
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PirateLabs
Scoot Enthusiast
Posts: 296
Location: Bowling Green, KY
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Post by PirateLabs on Aug 6, 2018 21:01:33 GMT -5
You say you: "Did the valves..." but then later ask about the flywheel. IF you did not have the flywheel set to the "T" mark making sure the 2 holes in the cam sprocket align with the top of the cylinder head, you may have set them so one of them is open a bit during the compression cycle (too tight) greatly reducing or eliminating compression, one of the key ingredients for a running engine. If you have little compression, I would start by re-checking the valve adjustment and, our host here, 90GTVert has a great video on how to make sure it is done right. Then, you can eliminate that as a possibility and move on to more expensive reasons for low compression.
Bill
PS I did not intend to sound mean or anything. It is just that if you had the fan cover off to line up with the flywheel "T" mark when you set your valves you could have seen if the key in the keyway on the crankshaft was sheared or not. My guess is that it isn't but again, better to check and know.
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Post by AtariGuy on Aug 7, 2018 1:58:37 GMT -5
I second the last post. You have to make sure it's at tdc and cam clocked just perfect when setting valve lash. Good luck
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Post by GrumpyUnk on Aug 7, 2018 12:13:50 GMT -5
Could be an adjuster jam nut worked its way loose... and the adjustment screw backed off, relieveing the valve of the opening/closing task for a while. Or the reverse, kept one of the valves from seating. That would make commpression tend towards zero.
Remove the plasti/rubber plug on the rear of the blower/flywheel cover. Look for the T mark. Use a 12mm socket and a breaker bar to turn the fan hub and rotate clockwise, watching for the T to come up. When it is even with the 'bar' at about the 9:00 o'clock position, the cam sprocket holes should line up with the gasket surface of the cylinder head. Adjust the valves with the crank/cam held at that position. After, rotate the crankshaft two turns(cam shaft just one) and re-check the clearance.
tom
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