My manual says to set the timing with the advance in it's rested position and that you only to advance it for the DT125 model.
But I've seen posts that say to adjust the timing with the advanced in it's advanced position.
So which is it? Do you adjust the timing with the advance in resting position or in advanced position?

Thanks
Jeff

Bottom line is whatever model you have either with the advancer or without, the timing on 125 & 175 models needs to be at 1.8btdc give or take.
So if it has an advancer then it must be held open & points set to break at 1.8.
If no advancer then at least that's one thing less to worry about & still breaking at 1.8.
Hope that helps.

Okay great. So the answer is that you adjust it with it advanced. It's strange because my manual says you only do that with the DT125A

Thanks

Just to confuse things more i thought the "75 DT175 had a fixed points cam & no advancer. The 125 you refer to has electric start & an advancer "call it governor". So in your case--"& i'm looking at the parts pics for "75 DT175--just a normal flywheel with a fixed cam so simply get the points separating at 1.8btdc & forget the gap--"don't even check it"--& then see how it runs.
If on the other hand you have an advancer in the flywheel then yours must be "74. Which needs holding open to the max & points set to break at 1.8btdc.

My 1975 DT 175B has an advance on it, I advanced it while setting timing, That is the way I understood the manual I have is it needs to be advanced to time it.

Jim

Sounds like the manual you're using is getting confused.
To give an example, on a flywheel like the "74 model 175 [& sounds like "75 model too from what ya saying]--if you 'didn't hold the advancer open' then your timing would be near tdc with 12+ thou gap.
Also the DT125 with electric start, same story, if not held open you'd be firing near tdc. But wait there's more--with a flywheel that has a fixed cam you automatically end up with close to correct 1.8btdc timing by doing nothing other than setting the gap. 1.8 is the key opening point sweet spot.

Thanks Jim. Yeah my 1975 dt175 also has in advance. The 75s definitely have it. My manual just must be wrong. It's said to only advance the advance for the 125s. I'll be doing mine just like you said.

i am just going through timing on my 76 /dt175C with advance
i noted when timing it the advance has travel past the limit set by the hole line up (i use a carb float pin to hold it open perfect size) which does affect the readings on the point checker and dial
so it can be held open further
i have just timed it with the hole lining up and the float pin in to keep open and started fine this time no kick back
D

You'll be ok, just ride & don't worry. Now, just to start you worrying, the foot of the spring arm wears where it engages in the cam plus the cam slot wears too so you end up double worn. Just keep moving bits greased including under the cam & arm pivot bolt. It's about as good as you'll get it ( in my opinion that is).

I checked mine and it doesn't overextend beyond the alignment holes. There is kind of a retaining piece of metal that it rests on and another piece of metal on the opposite side that stops it when the holes line up