T20 weak spark

AnKhe105 · Posted: Sat May 14, 2011 12:03 pm Post subject: T20 weak spark

What the heck else could cause a weak spark on one side. Too weak to fire that side. Have replaced and swapped the following NUMEROUS times: Points (gap checked over and over), plugs (gaps checked), condensors, Known good coils. Have checked and checked for a ground out??????????
GRRRR!

turbo_billy · Posted: Sat May 14, 2011 12:47 pm Post subject:

What about the plug caps themselves? Just a shot in the dark. Is the HT lead connection into the cap a good one?

Regards

Tim

AnKhe105 · Posted: Sat May 14, 2011 3:51 pm Post subject:

Thanks Tim. I guess I left that out of my list. Have changed the caps several times as well along with different coils. Problem persists. Doug

butch8231 · Posted: Sat May 14, 2011 7:33 pm Post subject:

have you check the polarity on the coils? or the contacts on the kill switch? or the hot lead from the key switch? hope I can help. cheers

AnKhe105 · Posted: Sat May 14, 2011 8:24 pm Post subject:

Part (most) of my problem is that I'm a novice on my own here. Pardon me Butch but how would I check the polarity on the coils? There is no kill switch. May be on to something with the hot lead from the key switch??? What would I be checking for? Voltage, continuity? Just have one of those cheap $8 multimeters from the dollar store but I noticed today for instance that one time I would have 12 volts at the points....then another time zero to a 0.5v?? (this was done precisely the same with each point open and key on). Could be the meter is faulty? (It's new). When I would get a zero reading, to test the meter, I went straight to the battery and it read 12v so I figured it must be ok?? WEIRD thing to me is that it would always fire up (even when reading zero at the points) but still weak on the right side??
Baffled....Thanks for any input. Doug

Rizingson · Posted: Sat May 14, 2011 9:46 pm Post subject:

Voltage will drop to near 0 at the points whenever they close and jump back to 12V when open. (that's good). Swap or change plugs, I recently had what looked like a weak spark, changed to a new plug and fired right up. Also check one more time if it is a fuel problem and not spark, that would tick you off if you've been kicking all day.

AnKhe105 · Posted: Sun May 15, 2011 5:41 am Post subject:

Probably made it a tad confusing. What I was trying to say was that I had 12v when open sometimes and zero again when OPEN another time. Both times with the key on?? Even when it read zero however, it would fire up?? Have a scrambler version with upswept pipes so when running, the weak side loaded up the "trap" in the pipe (like a water trap under a sink). Had to take the pipes off so that didn't happen. Spitting raw fuel something fierce out the weak side with no fire, cold to the touch. Nice and hot and smoky out the good side.
Have a pair of see through plug connectors on both sides so I can easily see how much spark there is (One end connects to the plug and the other end to the cap with a see through "bulb" showing the spark). Strong spark on the good side but about 1/2 on the bad.

Rizingson · Posted: Sun May 15, 2011 6:58 am Post subject:

Ok, you may have a poor connection where the primary wires to the coils are connected with bullet connectors to a single wire from the ignition switch. (a 1 to 2 connector under the tank) Also if you can turn the motor to a position where you lose voltage at the open point set, check what position the good set is at (open or closed). If closed remove the power at the good set and see if you now have a full 12V at the bad cylinder points. Also wiggle wiring around points and coil to see if it is loose or grounding out, to see if you can get 12V back to the points.
Good luck! I got confidence in you. I'm sure you'll solve it. I once found a hard to see intermittent short in the primary ignition circuit by running it in a dark shop and was able to see sparking up near the coils when moving wires around slightly.

AnKhe105 · Posted: Sun May 15, 2011 5:15 pm Post subject:

Thanks for the tips Riz! Will check it out tomorrow. Been working on wifey's car all afternoon. Will let ya know.

AnKhe105 · Posted: Mon May 16, 2011 10:58 am Post subject:

Did all the things you suggested Riz. Replaced one of the wires from the coil to the points and thought I had it. Put back together and then the good side quit. THEN, I had no voltage at either. Got into the headlight bucket and with the switch on, NO VOLTAGE at the hot lead! It has to be the switch so now shopping for one of those. THANKS a bunch! Doug

dorT500 · Posted: Fri May 20, 2011 6:19 pm Post subject:

AnKhe105 · Posted: Sat May 21, 2011 10:39 am Post subject:

dor...Not ignoring you and I thank you for putting up with me. LOL! Have been busy trying the things you said. Took battery out and charged it up good while I mowed the lawn. My sears charger read 12.6 when I got done. Have one of those cheap $8 mutimeters from the dollar store (problem???) and when I put that on it, went to 14. something volts. Will be studying up on continuity and the switch test link. Weird thing is SOMETIMES my cheap meter reads good voltage AT the switch with key on and sometimes zero?? When I see zero, I go directly to the battery to "test" the meter and it always shows good voltage. Shouldn't it ALWAYS show 12v directly ON the switch with key on???
Thanks, Doug

dorT500 · Posted: Sat May 21, 2011 11:39 am Post subject:

AnKhe105 · Posted: Sun May 22, 2011 12:27 am Post subject:

Switch came yesterday...Not it....sigh. Back to studying continuity. I'm almost sure it's something very simple now but haven't found it yet. Wanna come to Wi for about an hour?? LOL!

dorT500 · Posted: Sun May 22, 2011 7:12 am Post subject: