Topic: Nooby 350 twin question

[menzelg]

I just picked up a '71 350 twin to ride while I rebuild my 350F but i can't seem to make it fire up. It cranks and pumps fuel but no fire. The plugs look ok, the plug wires are new. The points are making contact but when I tested the points with an indicator light the right one doesn't light up. Even when I attach the clip directly to the wire. Is this a condenser problem? The wire appears ok (no breaks or worn spots). I was told that it hasn't run in a year+ and the guy I got it from quit riding it when it quit working.

I also managed to misplace my ohm meter in a move at some point so I am trying to avoid having to buy a new one but I'm sure once I do I will find the old one.

Thanks for the help.

[OldSchool_IsCool]

Lack of spark is definitly a problem.  I'm not familiar with the twins.  Does it have one or two point sets/coils?  I'd say trace the coil wires to the points, make sure there are no loose/broken joints.  Make sure the wires aren't pinched.

Once you get spark, double check that the spark is deliverd at the right time.  The points should open when the firing piston is near top-dead-center.  Search for "static timing" on the site here for instructions.

If you have spark and it's timed correctly, the next thing is fuel.  Smell the exhaust for unburned gas.  Check that fuel is flowing to the carbs.  Drain the float bowls, hopefully they have drains.

If you have a well-timed spark with a gas and it STILL doesn't fire, then you need to look into fuel/air mixture (read: carb rebuild) and compression.

[333]

You say the points are closing, but are they actually making contact?  There may be a spot of slag (formed by arcing when it comes close to closing but doesn't) that will not conduct electricity.  You could replace them, or buy a points file and file them smooth, readjust and retime.

[menzelg]

It has 2 points/coils and seems like basically half a 4 stroke. I replaced the plugs and filed the points down and managed to get the left side to spark but still nothing on the right point/plug. I think the starting issue is a combination of old crummy gas, incorrect timing, and this spark issue. The gas and timing I can fix but i'm stumped on the spark. I suspect the condenser or coil but I'm not sure. Any good ways to test these?

[oldbiker]

As a rather rough check, you could disconnect the suspect condenser
and try to get a spark at the plug. The points will almost cetainly spark a bit but for a short time it will be OK. If you can now start the bike re-connect the condenser while the bike is running and if it stops then you will know that the condenser is faulty.
If on the other hand, you cannot get any spark at the plug wiyh the condeser dis-connected then I would start checking power feed continuity to the coil and points.

[bryanj]

These motors simply will not start on 1 cylinder from cold so you need o sort out the spark problem first

[cb(r)]

if there is no spark then try replacing  the glass fuse under the seat.  it might be blown.  the connection gets corroded also.  it should be in a white or clear case that is suppose to help condensation.  however the cover doesnt work very well.  I got this tip from this site and it saved me a bunch of headaches .  also make sure you have a good, fully charged battery in the bike when trying to get running.  I dunno why this works but it made  getting the timing correct alot easier.  also a tip from this site.
good luck

[OldSchool_IsCool]

A bad condenser will cause your points to wear quicker.  Unless the wire lead on the condenser is broken, I don't see how a condenser would cause an otherwise correct ignition system to not spark. 

As a test, switch the plug wires to the opposite plugs AND switch the points wires to the opposite points.  Does the spark follow the switch or does it stay on the left?  If it follows, then the coil is suspect.  If it stays, then something in your points/condenser is at fault.

Definitely use fresh gas!  And a shot of starting fluid (VERY little) may help too.