engine swap

flaneledholes · 02-28-2015, 03:46 PM

hello first post here.
so bought a taotao cy-t3 with a blown 139qmb and a spare 139qmb. My question is the spare engine wont start. Not even with starting fluid. It is getting spark but is weak. I noticed the magneto wiring is different. Just wondering if I should swap then out to see if that helps? The spare engine emissions looks a bit different bit is the same theoretically. And the magneto has an extra wire. Now it still produces spark even without the extra wire I'm just wondering if it is messing with it by being different? I know I'm all over the place and its hard to understand my question but please do your best. Thanks

matt

bull · 02-28-2015, 06:38 PM

Welcome to the forum.

Before you get too carried away, remove the spark plug so the engine cranks easier. Then check the output Vac from the ac generator (stator / flywheel) with your DMM, it should be around 43Vac to 54Vac. The wire color is typically red w/ blk tracer.

If that is ok, check the gap on the plug.

If that is ok, check the valve adjustment and check the compression.

Then check to make sure you have a good seal of the exhaust pipe flange to the cylinder head.

Don't forget that the carbs in the GY6s are tuned to have the air box in place, if it is not connected they do run lean.

Do not concern yourself too much with the emissions controls differences, other than remove and plug all the vacuum lines at the intake EXCEPT the one to the fuel control valve. I have seen emission controls leaking vacuum and making it very hard to start. After it is running you can reconnect all the emission controls.

02-28-2015, 06:38 PM	#2
bull Join Date: Feb 2015 Posts: 257	Welcome to the forum. Before you get too carried away, remove the spark plug so the engine cranks easier. Then check the output Vac from the ac generator (stator / flywheel) with your DMM, it should be around 43Vac to 54Vac. The wire color is typically red w/ blk tracer. If that is ok, check the gap on the plug. If that is ok, check the valve adjustment and check the compression. Then check to make sure you have a good seal of the exhaust pipe flange to the cylinder head. Don't forget that the carbs in the GY6s are tuned to have the air box in place, if it is not connected they do run lean. Do not concern yourself too much with the emissions controls differences, other than remove and plug all the vacuum lines at the intake EXCEPT the one to the fuel control valve. I have seen emission controls leaking vacuum and making it very hard to start. After it is running you can reconnect all the emission controls.
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