Good morning everyone, 

This is my first post on this site so I hope I am doing this correctly. 

I recently acquired a 1975 dt125 off marketplace, does not currently runs but has good bones. It's pretty dirty but in good shape, very little rust. It does need a lot of replacement parts, but pretty much everything that is on it works as it should, besides the forks, autolube, and timing/points. 

I'm pretty much a novice to bottom ends but I do feel confident in doing a top end rebuild if necessary, compression is definitely lacking. My plan is to make sure the bike runs before tearing everything apart (besides the engine hopefully), cleaning, repainting, replacing, and so on until the bike looks as it should.

I am currently in the process of trying to get it running, and I did get it to run but turns out my timing was off and it was running in reverse. Since then I have ordered a tdc gauge to find 1.8mm btdc. The problem I'm running into is that the points are already open at 1.8, not just about to open. The timing plate that holds the points does not seem to affect when the points separate. From what I've read, advancing or retarding this plate should allow to adjust when the points open, but it does not. Even when the timing advance weights on the crankshaft rod are held open. I went ahead and read the service manual this morning, which confused me even more. Specifically the part where it says "from top dead center position, rotate the armature against the normal direction of rotation until the dial gauge indicates 2.5 - 3.0 mm travel. Then, in the normal direction of rotation, turn the crank until the dial guage reads 1.8mm btdc." What is the point of rotating the armature/crank 2.5mm in reverse? Just to see that the points are opening at 1.8 or some other reason?



Here is a link to a video of someone having the same issue at me: 

Howdy,

I myself am not sure however I would recommend watching this video:


its from Dale (Montana2strokeracer) setting the timing on a 1971 AT1 which is a little different then your 175 as this has electric start so it has a different charging system however you may find it helpful as Dale explains how the points open and everything with a dial indicator.

I'll watch the video later but the flywheel with advancer from one year only by memory all you need to do is somehow wedge the advancer open then with piston at 1.8btdc just losen the points screw & let them settle together so they start breaking at that moment. Can't go wrong except there's a bit of a knack to getting them breaking at that point because tightening the screw tries to change things unless you're lucky. Other thing is be sure the crank key is in one piece but if the flywheel nut is still tight then you should be good. Others may have a different method of doing things. Just what works for me. I see reading again you mention the timing plate ie stator plate but I thought on hose they're fixed by countersunk screws in which case points adjustment is all you have to play with. 

Scott, this is exactly what I’m trying to do. By the way it’s actually a 125 not 175 but I couldn’t edit the title.

 Unfortunately, my points are already open when I rewind to 1.8 BTDC. Advancing or retarding the stator plate seems to either have no effect on when the points open, or at least it doesn’t have enough rotation to make them open that early before TDC. I unfortunately made the mistake of removing the stator assembly, governor assembly, and center bolt previously, which makes me think I may have incorrectly reinstalled the governor assembly. When looking at the butt end of the governor (I think it’s called the cam lobe?), it has a small rectangular slot which I now believe is supposed to lock into a matching slot within the center hole of the stator where the crank bolt goes in. I’m thinking maybe this could be why I can’t get the plate to have an effect on the time of point separation? 

RT, thanks for the reply.

My bike is actually a 125. Not a 175. 

I do have access to the position of the stator plate, which can change position with the loosening of 2 screws. Unfortunately it seems that no matter the adjustment, whether advanced or retarded, the points still won’t break at 1.8 btdc.

i previously removed the governor advance assembly which has the cam lobe on the inner end. It has a small rectangular cut out on the end where I believe is supposed to lock into the slot of the center hole in the stator attaching it to the crank so the position is fixed. Unfortunately when I install this piece, it does not seem to lock into place but instead rotates freely until I install and tighten the center bolt. 

I will try to figure out how to upload video or photos to better explain this soon. 

Ok, thanks for correcting the model, so electric start 125.
I cant imagine how the advancer with cam can revolve if the locating tang is engaged.
But without the bolt does it drop a bit to miss the engaging piece. Not seen one for years but just looking at a parts drawing it shows a flange or extension past the tang to keep it square on for the bolt to hold it tight which makes sense & is what i remembered.
Does the tang need tweaking to engage.
Load some photos onto google photos & link them here--what i do--it only shows a link to click but it works.
No chance you're getting anti clock & clockwise confused?--sorry but had to ask.
Points are on a base plate with quite a range of adjustment but plate can be a fiddle as when you move it the points gap alters as the points plate never moves perfect.
I'll stop waffling on as i'm a bit out of ideas without looking at it.
More below
You say--as copied below.
"I do have access to the position of the stator plate, which can change position with the loosening of 2 screws".

So you mean the plate the points mount to which moves through an arc to alter timing.
Ok got that & the right model now. All good--well will be when you have it running forwards.
Man don't touch the kickstart if running backwards or she'll part the cases with a few revs on.

RT thanks for the reply, 

from what I can feel when placing the advancer in the center hole, it does not engage or lock into place where it seems it should- the cut outs pictured below. Although, rotating the advancer by hand without the bolt down, it seems to touch it tight enough to slightly spin the armature and open the points, but feels loose it can rotate independently while inside, which seems like something that shouldn’t occur. The tang on the armature may need tweaking but I’m unsure of the best way to do this. 

In regards to the direction of rotation when finding tdc, I rotate counterclockwise as shown on the marking— bottom left of the stator behind the orange wire—to get to tdc and zero in with the gauge. I then rotate in the reverse direction -clockwise- to find 1.8mm btdc. Before all that I set my max gap-.012in. After finding 1.8btdc I notice that points are already open at my max gap. Adjusting stator plate clockwise/counterclockwise does not close the gap unfortunately. 

here’s a link to view pictures - 

and I’ll be sure not to kickstart for now. Thanks again and let me know what you think. 

Apparently I'm not allowed to post links- "The links and images in your message has been removed, because your aren't allowed to use them" Please advise.

Here is the link with spaces

h t t p s : / / p h o t o s . a p p . g o o . g l / 8 N d u Z s G 3 D P p q i H h Q A

I'll get back, dinners on the table or the cat will have it. I guess you have a center plug head? as i can't see how a dial gauge can work on an earlier angled plug hole.--Later--.

RT, 

The spark plug hole is angled but the gauge seems to work just fine.