Planet Minis

TTWR77 · 06-22-2009, 12:32 PM

New member with a bad Honda habit here. I raced MX for several years and even worked for a dealer for a while. I always liked the trail 70ies and picked up a decent CT70HK0 for a pit bike. That got my habit started and I couldn't pass up a second CT70H when I came across it. To add to the CR and both CT's I managed to pick up a TRX250R and a Rincon. (I wont go into the power equipment here) This past weekend I found a clean 86 TRX70 on craiglist and grabbed it for my daughter. I suspect it has a bad coil which is what I'm here for. It starts first pull and runs great when cold but dies as it warms up and wont restart until it cools down. Does anyone have any idea what the resistance on that coil should be? I'd like to test it cold, ride till it dies and test it again but would like to know what it should be.

Thanks for any help or suggestions you may have.

dirtbkr188 · 06-22-2009, 03:03 PM

According to the Clymer Manual, it just states that continuity should exist, on both the primary and secondary reistance tests.
Primary - Set the ohmmeter at R x 1, and measure the primary terminal and the mounting flange.
Secondary - Set the ohmmeter at R x 100 or R x 1000, and measure between the secondary lead (spark plug lead) and the mounting flange or green ground wire.

TTWR77 · 06-22-2009, 08:55 PM

Thanks for the reply. Tonight I rode it till it died, pulled the plug and it still had spark. After it cooled down I fired it back up for a little more investigating. Sprayed the intake with brake cleaner and found the problem. It has an air leak at the insulator between the carb and the manifold. (intake tube?) I suspect the leak gets worse as it heats up until it reaches the point it wont run. Thought about smearing it with grease to see if it solved the problem but by that point dinner was on the table. I'll play with it more tomorrow.

Thanks again.

cdoublejj · 06-23-2009, 01:08 AM

could it also be that condenser my lt50 died after it got warm fora while and now has no spark.

dirtbkr188 · 06-23-2009, 06:45 AM

Quote:

Originally Posted by cdoublejj

could it also be that condenser my lt50 died after it got warm fora while and now has no spark.

There is no condenser on the TRX70, it is a CDI-type ignition.

06-22-2009, 12:32 PM	#1 (permalink)
TTWR77 PM Newbie Join Date: Jun 2009 Posts: 2	introductions with an ignition question New member with a bad Honda habit here. I raced MX for several years and even worked for a dealer for a while. I always liked the trail 70ies and picked up a decent CT70HK0 for a pit bike. That got my habit started and I couldn't pass up a second CT70H when I came across it. To add to the CR and both CT's I managed to pick up a TRX250R and a Rincon. (I wont go into the power equipment here) This past weekend I found a clean 86 TRX70 on craiglist and grabbed it for my daughter. I suspect it has a bad coil which is what I'm here for. It starts first pull and runs great when cold but dies as it warms up and wont restart until it cools down. Does anyone have any idea what the resistance on that coil should be? I'd like to test it cold, ride till it dies and test it again but would like to know what it should be. Thanks for any help or suggestions you may have.

06-22-2009, 03:03 PM	#2 (permalink)
dirtbkr188 3rd Gear Member Join Date: May 2004 Location: New Jersey Posts: 2,972	Re: introductions with an ignition question According to the Clymer Manual, it just states that continuity should exist, on both the primary and secondary reistance tests. Primary - Set the ohmmeter at R x 1, and measure the primary terminal and the mounting flange. Secondary - Set the ohmmeter at R x 100 or R x 1000, and measure between the secondary lead (spark plug lead) and the mounting flange or green ground wire.

06-22-2009, 08:55 PM	#3 (permalink)
TTWR77 PM Newbie Join Date: Jun 2009 Posts: 2	Re: introductions with an ignition question Thanks for the reply. Tonight I rode it till it died, pulled the plug and it still had spark. After it cooled down I fired it back up for a little more investigating. Sprayed the intake with brake cleaner and found the problem. It has an air leak at the insulator between the carb and the manifold. (intake tube?) I suspect the leak gets worse as it heats up until it reaches the point it wont run. Thought about smearing it with grease to see if it solved the problem but by that point dinner was on the table. I'll play with it more tomorrow. Thanks again.

06-23-2009, 01:08 AM	#4 (permalink)
cdoublejj 3rd Gear Member Join Date: Oct 2008 Location: St.Joe MO Posts: 1,367 My Mood:	Re: introductions with an ignition question could it also be that condenser my lt50 died after it got warm fora while and now has no spark.

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