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Discussion Starter · #1 ·
Ok, I'll start of by saying I'm only slightly mechanical and I'm in over my head. I'm trying to fire up my 500t for the first time and it will crank, pop, and backfire but that's it. I have checked spark to both plugs and it's good. I have checked both fuel lines and there is fuel in them. There is a smell of gas in the garage and when I crank it it will pop and I get a shot of blue flame out of the tail pipes. Please help me, I want this old girl running before bedtime :(
 

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Sensei
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ANY engine needs only three things to run:
Compression
A fuel/air mixture to compress
And spark at the correct time
If you aren't running, at least one is absent

Check compression...A 500T should have AT LEAST 163 PSI in each cylinder...It can run on/with less but is hard starting and produces less usable power.....163 is factory spec minimum....( A cold test will read about 10 to 15 PSI low)....

Gas in the fuel line or even carb bowl doesn't verify it's getting through the jets to the cylinders... Clean the carbs......

Spark....Well, on Hondas of this era, a very good battery is a must to get a clean spark and it must occur at the exact timing index.... Add Check battery and set point timing......

NOTE: an engine can run (for a short while) without oil, but it's not a good idea...
(Just teasing, I have a weird sense of humor)...Let us know the results of the compression check, etc, etc... I'd suspect it's a timing issue, but all the other things need to be checked as well....Steve :D
 

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Sounds like your timing is definately off.
 

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Discussion Starter · #4 ·
I took the points cover off and set them according to the manual but I am getting very little spark, intermitant at best. When it sparks I get a pop out of the exhaust then nothing as the spark stops. Any suggestions?
 

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Sensei
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How good is the battery?...
Did you clean and reset the points, or just adjust them?
 

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Discussion Starter · #6 ·
No battery issues and the points were cleaned when the top end was rebuilt, they look like brand new. I'm thinking I have a wiring issue, maybe bad ground somewhere? When it was taken apart there were 3 of us and a flat of good canadian beer, I was trying to take pictures of things but my mechanical friend was taking things apart quicker than I could log them so it's possible I have hooked something up wrong. back to the garage I go.........
 

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Sensei
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A direct ground from battery negative to the point plate (temporary) will diagnose/verify that in a heartbeat.........Alligator ended jumpers are the bomb!......
 

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Discussion Starter · #9 ·
Still no steady spark to the points, grrrrrrrr I get a spark when I first press the ignition, the just every now and the aftewr that :x
 

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Sensei
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Two points to make (sorry about the pun).....
1. Just because you don't SEE sparks at the points does NOT mean they aren't triggering the coils properly.... Once the capacitors charge-up, the sparks at the points should/can become almost invisable....That's what the capacitors are for: to prevent excessive arcing (that causes metal transfer) at the points.....

2. Old Honda "kill" switches are notorious for failing during vibration (like when starting)..... To make SURE that isn't your problem (or verify it is), run another alligator jumper direct from B+ to the black/white stripe coil wires (both coils)...This "hot-wires" the ignition on and eliminates ALL the possible harness/wiring problems except the coils to points wires. IF it still won't spark regularly and the points and points wires are good, intermittant coils are likely...
DO NOT leave it "hot-wired" for longer than 10 minutes at a time (unless the bike is running) as you can "cook" the coils....

Let us know results......
 

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Discussion Starter · #13 ·
I think you may be right about the spark being almost invisible and I'm starting to think it may not be the problem since I get good spark to the plugs. It almost seems like it's loading up on fuel and flooding itself so I think I'm going to move to the carbs for a bit and check the float setting.......
 
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