I have this manual.



I read the whole autolube section but didnt see anything about a flow test. Is it covered in some other section? Is there a different shop manual i should get?

Thanks
Jonathan

Not that familiar with the DT250 series, but I know guys here have discussed the number of cc's that should flow at idle. Maybe you should PM DEET, since he works on so many pumps for us.
Sorry I'm not of more help.

This is the best I could find... the (much) later Service Manuals have the specs included. Early ones don't. DEET would be the one to consult.

The specs in the table (found in a general Enduro manual in the Tech Library) is cc's per 200 pump strokes with the pump at minimum (left column) and then with pulley rotated to maximum (right column)

On the early pump you can rotate the starter wheel and count 200 strokes. On the later bikes you run on premix and run the engine and count the 200 strokes since they don't have a wheel.




.

Also, check around post #78 on this thread. Someone was running just such a test on the output for a DT-3:
yamaha-enduros.com/index.php/forums/main...build?start=70#11435

Very cool! Thank you mothersbaugh and mark t.

Note that the chart I posted doesn't show the first DT1... not sure if you have a first year engine or not?

The pump might have different ratings for the first year.

In the later years, Yamaha started to standardize the pumps quite a bit. The "per 200 stroke" output started to be the same and Yamaha changed the gearing to run the pump faster (more oil) or slower (less oil) depending on the model.

My engine is an early dt1. It has a 4 digit unit number 90xx.

I think it would be safe if every 200 strokes at minimum it put out 1cc and 9cc per 200 strokes with pulley at max...

I just couldn't find the specs and don't know enough to tell you that the DT1b had the same pump gearing and specs.

You might try contacting DEET and asking him if he knows.

Finally got around to measuring the oil volume. I came up with 1.2 cc at minimum stroke and a little over 9 cc at max stroke so i guess im good to go.

Well it's amazing how little a motor requires under ideal circumstances--back in the "70's with our AG100 farm bikes we sold by the truck load at work the ones that were running the cleanest --pipe & plug--were the ones that came in with a rusted & broken oil pump cable so pump had dropped back to minimum stroke. Probably been like it for who knows maybe 12 months & probably only bought it in because of something else haha. Must've been running it fairly gently around the farm & no extended flat out stuff down the road. The cable used to rust where it passes through the adjuster even though by memory the adjuster had a nylon bit through there for the cable. Anyway--something about nothing really, again lol.