Magneto coil failure?

[duivendyk]

I think the HT CDI unit is pretty marginal,that is underdesigned.It's sort of 'pot luck' with these things,depending on the components used.Some may last a long time,moisture in high voltage circuits is murder because of high dielectric constant of water (80!).May be the prudent thing is to bake them at low heat first and then encapsulate them in silicon rubber.The ignition cable entry is particularly vulnerable because it goes to the pulse trafo.

 

[michaelb]

Please need help. Is my magneto bad? I got this bike from a guy who said he never got it to run. I've gone through pretty much everything; tank, carb, gaskets, plugs, and the most I get is a few farts. I checked the spark and it does get spark but it doesn't seem too strong. if I hold the plug, the electric shock is not bad at all, nothing like my lawnmower that gives a good snappy jolt. I also have a six volt headlight wired up and on a push start it does light up. I have a switch on the light so it is not always on. What are the chances the magneto or the magnet are bad? mikes

 

[Al.Fisherman]

Please need help. Is my magneto bad? I got this bike from a guy who said he never got it to run. I've gone through pretty much everything; tank, carb, gaskets, plugs, and the most I get is a few farts. I checked the spark and it does get spark but it doesn't seem too strong. if I hold the plug, the electric shock is not bad at all, nothing like my lawnmower that gives a good snappy jolt. I also have a six volt headlight wired up and on a push start it does light up. I have a switch on the light so it is not always on. What are the chances the magneto or the magnet are bad? mikes

Magnet bad?? never seen one go bad in my lifetime. Take a screwdriver and watch the magnet snatch it when you get close. Disconnect the light totally and try to start again. Actually sounds like a weak magneto but you can check that by spinning the engine over (pull) or take plug out for easier revolution. Check voltage output. Between 6 and 7 volts. If good voltage I'd check the magnet key and after that the CDI.

 

[Al.Fisherman]

Want to know if it's your mag??? Connect a V meter to both leads comming from the block(your mag). Pedal like the ****ens and dump the clutch. Check your V reading. If you get 5V or above it's something after the mag. Use alligator clips on your test meter and be careful not to get tossed over the handle bars!

If checking magneto this way, remove the plug for easier peddling. Tape plug to frame with the CDI wire and boot hooked up.

 

[michaelb]

After trying just about everything and rebuilding or replacing just about every component it was suggested to look at the magnet/timing. There was no key in the magnet/crankshaft. Timing was nowhere. I bought this bike as a non-runner and the seller said he never had it running. Maybe it came from the box that way. Anyhow now it runs; now if I can only keep the chain from jumping off. mikes

 

[tacoshell4]

haha so u added a key and it ran?

 

[210061741]

1 time i bought a GT-5 and the key was really small.

the magnet was floppin around.

I put a new key in it.

 

[Al.Fisherman]

After trying just about everything and rebuilding or replacing just about every component it was suggested to look at the magnet/timing. There was no key in the magnet/crankshaft. Timing was nowhere. I bought this bike as a non-runner and the seller said he never had it running. Maybe it came from the box that way. Anyhow now it runs; now if I can only keep the chain from jumping off. mikes

Glad you checked your key. After re reading my post I see that I meant to say "if NO voltage check the key" and NOT if "good voltage". I've worked on just about any engine imaginable from these HT's to large 2 cycle outboards, small 4 cycle to big block V-8's and throw in a few diesels and these HT's have to be the easiest to diagnose and repair.

 

[danlandberg]

Two CDI coils in one day

I have about 70 mi on an engine before the rear mount stud broke off. I put my 2nd engine (new in box) and rode it for about a week, stopped at the store and it started and went about 20 feet and died & would not start again would pop about 5 revolutions and then nothing (like it was not getting enough fuel. Peddled it home and checked carb and nothing was clogged, fuel flow was OK. Took the CDI from the still in the box kit, Then it ran for 15mi. The same thing happened. I then checked the resistance of the mag. The manual said it should read 323ohms blue to black & 2.3ohms black to white. Mine read 346ohms blue to black & 5.9 black to white. The readings on the engine I took off were 338ohms blue to black & 2.5ohms black to white. That's closer to the book. I now need a CDI! The engine(s) ran good until this! I am starting to really dislike the F-ing Horse junk. And the manual counterdics itself on how to hook the kill switch up. Pg 05 step 6, hook 1 kill wire to 1 CDI wire & the other wire to the other CDI wire. Pg 7 step 9, hook 1 kill wire red/yellow to white & green kill wire to ground. How do you check the CDI? ANYONE know?

 

[Al.Fisherman]

Dan, can't help on the CDI but both ways of hooking up the kill switch will work, I use the wires on the CDI on all my builds. I've had I CDI go bad and that was within 3 days of receiving the kit....Hence my signature on "Luckyearlybird"

Got this off of another forum......

All of my honda OEM service guides, Xrs, XLs, Nxs...

all have the same wording..

If the CDI is suspected to be bad, the only reliable way to test it is to swap it for a known good unit. If the bike runs, the former CDI is bad. NO S**t

OK Dan... Tell me why the engine stud broke... How did you have the engine aligned with the frame... http://www.motoredbikes.com/album.php?albumid=1018