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No Spark, Bad Exciter Coil I believe

Posted: Wed Aug 10, 2011 8:37 am
by DKAudio
*update 2/24/12...My original thread post is below, I found that the alternator exciter coil is believed to be open at this point.

My 1985 Aero 50 is super hard to start after it sits for 2 days or more. It doesn't even really fire and usually when I crank on it for a long time (multiple minutes) it will start to fire and eventually start. If I start it everyday it starts almost immediately. I tested my auto bystarter by removing it and putting 12V on it and it did heat up and move out. I also pulled the vacuum line and gas line off the carb, sucked lightly on vacuum line and gas flowed. Any ideas? This morning I cranked so long that my new gel sealed battery started to die, now I have to buy a charger :(

Re: Aero 50 really hard to start after it sits for 2 days or

Posted: Wed Aug 10, 2011 8:53 am
by bradmeehan
My experience with those symptoms is the carb seals are dried out and it's sucking air there. That would also allow the gas in the bowl to evaporate and have to refill when you crank it. You can get carb rebuild kits that include all of the seals.

Re: Aero 50 really hard to start after it sits for 2 days or

Posted: Wed Aug 10, 2011 11:23 am
by dun rite
+1

Re: Aero 50 really hard to start after it sits for 2 days or

Posted: Wed Aug 10, 2011 12:38 pm
by Bear45-70
Either that or the petcock is bad along with the needle and seat and the engine is flooded. Crank it for about 5 seconds, pull the plug; dry = the first issue, wet = the second.

FYI, my 1985 Spree always takes about20 seconds of crank to start after it sits for a couple days or a week or months.

Re: Aero 50 really hard to start after it sits for 2 days or

Posted: Wed Aug 10, 2011 1:13 pm
by DKAudio
Thanks for the advise. I will say that I did a complete carb tear down and cleaning a few months ago, it ran a little better but the starting issue was the same. I did not see any dry seals/gaskets and I have tried spraying carb and choke cleaner all around the carb when the scooter is idling, it did not change RPMs at all.

Re: Aero 50 really hard to start after it sits for 2 days or

Posted: Wed Aug 10, 2011 6:07 pm
by SuprasNsprees
Bear45-70 wrote: FYI, my 1985 Spree always takes about20 seconds of crank to start after it sits for a couple days or a week or months.

+1

and i've got a freshly rebuilt carb , and a brand new battery

Re: Aero 50 really hard to start after it sits for 2 days or

Posted: Wed Aug 10, 2011 8:14 pm
by DKAudio
SuprasNsprees wrote:
Bear45-70 wrote: FYI, my 1985 Spree always takes about20 seconds of crank to start after it sits for a couple days or a week or months.

+1

and i've got a freshly rebuilt carb , and a brand new battery
Mine is minutes though, if I start it everyday it fires after only a few cranks (1-2 seconds).

Re: Aero 50 really hard to start after it sits for 2 days or

Posted: Wed Aug 10, 2011 8:24 pm
by Bear45-70
Are you opening the throttle while starting?

Re: Aero 50 really hard to start after it sits for 2 days or

Posted: Wed Aug 10, 2011 9:01 pm
by DKAudio
Bear45-70 wrote:Are you opening the throttle while starting?
Yeah

I tried cranking for about 5 seconds with open throttle and pulled the plug, it looked a little wet but was kind of hard to tell. It certainly wasn't either extreme, dry or dripping. I put the plug back in and cranked some more and it looked the same the second time around.

Re: Aero 50 really hard to start after it sits for 2 days or

Posted: Wed Aug 10, 2011 9:13 pm
by Bear45-70
Cold starts require that the throttle be CLOSED or the bystarter will not supply extra fuel for the cold start. Warm starts often require added throttle. Cold never.

Re: Aero 50 really hard to start after it sits for 2 days or

Posted: Thu Aug 11, 2011 8:35 am
by DKAudio
Bear45-70 wrote:Cold starts require that the throttle be CLOSED or the bystarter will not supply extra fuel for the cold start. Warm starts often require added throttle. Cold never.
Really? Wow, that's interesting, I had no clue. Guess I'll try cranking without touching the throttle when I get home, thanks.

Re: Aero 50 really hard to start after it sits for 2 days or

Posted: Thu Aug 11, 2011 11:11 am
by Bear45-70
DKAudio wrote:
Bear45-70 wrote:Cold starts require that the throttle be CLOSED or the bystarter will not supply extra fuel for the cold start. Warm starts often require added throttle. Cold never.
Really? Wow, that's interesting, I had no clue. Guess I'll try cranking without touching the throttle when I get home, thanks.
To pull the fuel from the bystarter bowl requires vacuum, opening the throttle lowers the intake vacuum, hence no extra fuel for the cold start.

The owner's manual specifically states "4. With the throttle closed, push the starter button (4). Release the starter button as soon as the engine starts.

NOTE:
Do not use the electric starter for 5 seconds at a time. Release the starter button for approximately 10 seconds before pressing it again."

Re: Aero 50 really hard to start after it sits for 2 days or

Posted: Sat Aug 13, 2011 5:01 pm
by DKAudio
Well, I found that I don't have spark. I did some resistance readings per the manual...
The coil resistance seems fine.
The pulse generator was good, about 160 ohms.
The alternator excited coil gave me a reading in the mega ohms.

Should I replace that or do you have any other troubleshooting tips to make sure?

Re: Aero 50 really hard to start after it sits for 2 days or

Posted: Sun Aug 14, 2011 11:25 pm
by maxreverb
Bear45-70 wrote:
DKAudio wrote:[quote="Bear45-70
The owner's manual specifically states "4. With the throttle closed, push the starter button (4). Release the starter button as soon as the engine starts.

NOTE:
Do not use the electric starter for 5 seconds at a time. Release the starter button for approximately 10 seconds before pressing it again."

are the owners manuals archived somewhere on here like the service manuals?

Re: Aero 50 really hard to start after it sits for 2 days or

Posted: Sun Aug 14, 2011 11:45 pm
by Bear45-70
maxreverb wrote:
Bear45-70 wrote:
DKAudio wrote:[quote="Bear45-70
The owner's manual specifically states "4. With the throttle closed, push the starter button (4). Release the starter button as soon as the engine starts.

NOTE:
Do not use the electric starter for 5 seconds at a time. Release the starter button for approximately 10 seconds before pressing it again."

are the owners manuals archived somewhere on here like the service manuals?
Some of the owners manuals are in the service and owners manual section.