Hi all,

I've been slowly getting a '74 dt125 into running condition, but I'm having some problems with it now at high speeds. The bike seems to cut out after I've ridden it for about 5 minutes and when I've gotten it up to around 55mph. I'm guessing it may be heat related but I've noticed two things:

1. Any draw on the electrical system seems to stall the motor once it's hot (headlight, brake light, turn signal). The bike runs fine with lights when it is cool.
   
2. The clutch doesn't seem to disengage when the bike is hot, even when I squeeze the clutch handle all the way.
   

I don't know if the clutch problem is related and I'll try adjusting it tonight, but I had it adjusted at the shop not too long ago. Another complicating factor: the starter worked when I got the bike but after I got it back from the shop (crank seals replaced) it didn't work - not their fault, of course. I had checked the starter terminals with a voltmeter and it seems to get voltage, but doesn't turn over. I'm wondering if it might not be generating also.

Any ideas how to diagnose this? I haven't ridden this bike much and I'm new to biking in general, so any comments are welcome - I just don't know what's normal and what's not on this bike.

Thanks for your help!

Steve

No takers? To much info?

I had the bike out again last night an it cut out before I reached the end of my block. I re-tightened all the accessible electrical connections, but no change. I will follow the steps in Clymers to check generator output when I get a chance.

I think the clutch might be ok - I'm just hearing the gearing when the bike stops running and I'm still rolling. I can't seem to get it into neutral while I'm coasting.

Any suspect electrical components I should check while I have the voltmeter out?

No takers? To much info?

I had the bike out again last night an it cut out before I reached the end of my block. I re-tightened all the accessible electrical connections, but no change. I will follow the steps in Clymers to check generator output when I get a chance.

I think the clutch might be ok - I'm just hearing the gearing when the bike stops running and I'm still rolling. I can't seem to get it into neutral while I'm coasting.

Any suspect electrical components I should check while I have the voltmeter out?

Out of my comfort zone with this Steve. However if you PM me you email address I have scanned starter generator testing from my Haynes manual and I will send it you.

...Paul

I tried to measure generator output per Clymers and Haynes, but I don't see terminal markings for anything but E. The procedure calls for jumpering two terminals, etc.

Does anyone know if the wiring shown here is correct? I suspect the middle orange and dark green wires might be switched because of the color code sticker above, but I can't find a diagram with wire colors. The bike runs, but electric start does not work.

Is this right?

Thanks!

Well, I fixed this problem after a bit of staring at wiring diagrams (thanks Paul) and no it didn't take me a year. I'm just a little late in responding with the fix.

The shop had gotten some wires switched around which is why the starter wouldn't work. Once I realized the light green wire was screwed to a mounting terminal everything fell into place. I've got a picture of the correct connections somewhere... basically move the light green wire to the right one space and move the dark green wire to the right two spaces (between the orange and white).

One other thing that confused me was the terminal letters listed in Clymers. For various tests, they reference terminals A, F, E, and M but only E seems to be marked on the starter/gen. After going cross-eyed looking at the diagrams, I realized that A is the white wire, F is green (dark green), E is black, and M is light green.

I'll try to find that photo of the correct connections to post.

Thanks!

Steve

I've got a picture of the correct connections somewhere...

Thanks Steve for your work ( that shared your solution also)!

I have also the problem with right position of wires on a terminal.

Can you please to post here a big picture of right position of wires ?

Alexander

this helped alot . i actually mounted the starter generator on a 78 dt175. had to cut magneto alignment tabs out,had to cut a u shape for the cylinder hump.and a flat spot for the clutch release post, changed crankshaft to a 75, and had to make custom cover. every thing seems to work even had to bend shifter a bit to make clearance . so i think i am good to go.

i forgot i also found a tank with small dent that is green paint and i think its better than balboa blue

Have you got a picture of how it should be - that would be a handy reference

just reading the thread and I think.. that this is what he said he did.. i coloured in the screws. to represent where the wires would go.. the orange one wouldnt move and the 1st one where the light green is is not used.. .

this is just going from the verbal description though.