JW896 Posted September 2, 2010 Posted September 2, 2010 I recently bought an ’81 DT175H Enduro. It has about 9600 miles on the speedometer. It had not been run for a couple of years. I cleaned up the bike; cleaned the fuel tank; replaced all of the fluids except for the 2 cycle oil; replaced the plug; removed the carb and thoroughly cleaned it and made sure the jets were clear. I removed the oil pump cover plate and bled the oil pump. I had to bump start it to get it running. I was running premium fuel (no Oil mix). The pump was activating. I ran it for about 10 minutes and ran through the gears. The bike quit and when I restarted the engine, I noticed that the red oil indicator light was lit up. I killed the engine and rolled it home. I added 2 cycle oil to the fuel and started to troubleshoot the oil pump. I checked the minimum clearance between the adjuster plate and oil pump head. I removed one thin shim and the gap spec’ed out at .025. (The specs call for .020 to .025). I pulled the oil line from the oil pump and filled the line with 2 cycle oil and plugged the open end. I started the bike and the oil pump is pumping oil. I replaced the oil line, bled the pump again and started the bike. The red oil indicator light is still on. So I am reluctant to run the bike not knowing whether I am getting enough oil to cylinder. I am not sure whether the oil light will go out if I keep running it with the fuel/oil mix. I’d appreciate any suggestions for troubleshooting the pump, checking the quantity of oil output, and checking the oil indicator light.
Moderator Airhead Posted September 2, 2010 Moderator Posted September 2, 2010 The oil light is nothing to do with pressure...or the pumps function in any way, It is there as a level warning indicator. As such it is importand you know the bulb is good and so you will find it permanently on when in neutral, it will go off when in gear as long as there is sufficient oil in the tank. Pump bleeding...remove the small screw from the top of the pump until bubbles cease to come out and oil flows freely from the hole. Pump priming...start the engine and allow to idle, turn the pump pulley by hand until the pump is stroking at maximum, hold it there for around 30 secs or if you have a clear oil line to the carb...untill you see no air in it.
JW896 Posted September 2, 2010 Author Posted September 2, 2010 The oil light is nothing to do with pressure...or the pumps function in any way, It is there as a level warning indicator. As such it is importand you know the bulb is good and so you will find it permanently on when in neutral, it will go off when in gear as long as there is sufficient oil in the tank. Pump bleeding...remove the small screw from the top of the pump until bubbles cease to come out and oil flows freely from the hole. Pump priming...start the engine and allow to idle, turn the pump pulley by hand until the pump is stroking at maximum, hold it there for around 30 secs or if you have a clear oil line to the carb...untill you see no air in it. That all makes sense because I first noticed the oil light was on when it was in neutral. The oil tank was about 1/3 full. I topped off the oil tank and started troubleshooting. I never took the bike out of neutral while I was checking out the oil pump. I did bleed the pump and got no bubbles, but I did not prime the pump by cranking the pully cable. I'll give it a try. This bike has a self adjusting cable arrangement. Do you think I need to do anything with it adjustment wise? Thanks for info!! JW
Moderator Airhead Posted September 2, 2010 Moderator Posted September 2, 2010 This bike has a self adjusting cable arrangement. Do you think I need to do anything with it adjustment wise? Thanks for info!! JW Not sure what you mean by self adjusting, the more the throttle is opened the more the pulley turns which allows the pump stroke to increase. The only adjustment is to use the cable adjuster to align the pip on the pulley with the pin that is in the end of the pump shaft at closed throttle.
Moderator Airhead Posted September 2, 2010 Moderator Posted September 2, 2010 Ahh I see yours is a later cable arrangement than mine and does indeed have a self adjusting cable. not sure what the issues are but just check that the pully hits the closed off position pip and peg aligned...at the same time as you hear the carb slide 'clunk' shut...well thats what i'd do.
JW896 Posted September 2, 2010 Author Posted September 2, 2010 Ahh I see yours is a later cable arrangement than mine and does indeed have a self adjusting cable. not sure what the issues are but just check that the pully hits the closed off position pip and peg aligned...at the same time as you hear the carb slide 'clunk' shut...well thats what i'd do. I was going to send you a exerpt from the manual but I could'nt figure out how to cut an paste it or link it. But it sounds like you found the reference. I did prime the pump as you suggested and confirmed that the pip and peg are aligned. It seems to run fine. A bit smoky, since I still have some mixed fuel in the tank. Now all I need to do is get the carb adjusted a bit and I am off to the dusty trails! This bike has a Mono-Cross single shock that runs from the rear swingarm to the center of the frame under the fuel tank. It is one sweet ride and fast. It seems to be smoother than my '74 DT175 with the dual shocks in the rear. I did get the top end bored out on the '74 after breaking the piston skirt. Now all I have to do is get it re-assembled. Once I get it running it should be an interesting comparison. Thanks again for the help. I really appreciate it... JW
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