Oiler and Carb question
I think I have a '81 Yamaha DT 175, apparently there are 3 versions of the 175. Mine is a 2 stroke. It was given to me after sitting for about a year. I think it is a DT because it has lights and turn signals and I had to buy a part and the DT stock list IPB had the part I needed. One of the other two models also had the same part number, but I forget which. Another reason is the only book I could find was combo Clymer’s for the DX and XT and although similar, does not look like either. Any way to determine which I have?
Now for the real questions. After getting it running, I have a couple if issues.
1. The Oil indicator light stays on. It has a separate reservoir for 2 cycle oil. Since I don’t know the proper term for it, I’ll call it the ‘Oil Controller’ basically, it is a mechanical driven pump that has fresh oil line coming into it from the reservoir and is shaft driven by the engine. The oil amount is controlled when the throttle is rolled. A single throttle cable goes into a box on one side, comes out as two cables on the other - one connects to the carburetor and the other to the oil controller.
As best I can tell, oil is getting to the engine side of the oil controller because I removed the oil controller and raw oil was present, by raw I mean it was just as clean as from the oil reservoir.
How can I confirm oil is getting into the cylinder? After running the engine for about 5 minutes, I took the plug out and it looked pretty ‘dry’, I was expecting it to appear a bit wet if oil was getting into the cylinder. Does it take a while for the oil to circulate? I am afraid to run it too long for fear of causing damage. Of course the oil reservoir was empty when I got it.
2. I am having trouble with setting the idle. I think it may be related to the float level. After about 5 minute warm up It will only idle if the choke is part way on which makes me suspect the float level is set too low. Another reason I suspect it is too low is because if I shake the bike from side-to-side or bounce on the seat it will die (as in not getting fuel). I took the carb apart before I got it running and it was surprisingly clean. No sticking parts or ‘varnish’ from old fuel. The fuel flows out of the tank in a steady stream when disconnected from the carb. The bike also starts really easy even when cold (1 or 2 kicks).
I can’t determine the location of the idle adjust screw because the resolution of the picture in the book isn’t good enough to figure out what the arrow is pointing too. There are two candidates; one is a knurled bolt with a tensioning spring on the bolt that I can adjust without any tools. This is about center of the carburetor, on the top half of the carb (bottom half being the float bowl). It looks as though if it adjusted all the way in, would keep the throttle from closing completely. I think this is air mix only. There is also a small set-screw to the right of that at a slight angle. I think is the idle screw. I cranked it all the way, both directions, which was only about 4 turns, but did not notice much of a difference.
Thanks in advance!
Last edited by sans1; 04-26-2008 at 03:25 PM.
Reason: left out year of bike