400 two stroke oil pump adjustment
#1
400 two stroke oil pump adjustment
Checking the adjustment on one of the two stroke 400's I have in my herd. Pulled the cover off and it's a bit different than the other ones I have done. I found a mark on the arm of the oil pump, but not sure what it is supposed to line up with. I can see a faint mark up by the word mikuni but no other lines on the pump housing itself. How does this one get adjusted?
Thanks
Mike
Thanks
Mike
#2
With the carb properly adjusted first, you will see 2 lines stamped into the cable guide plate. You might have to clean it off to see. when you rotate the plat there should be another line stamped into the aluminium pump body, the mark should be stamped in 7 oclock position. when the bike is at idle the lines should line up. ill take a pick and show you what i mean.
#3
Pump markings for adjustment
Checking the adjustment on one of the two stroke 400's I have in my herd. Pulled the cover off and it's a bit different than the other ones I have done. I found a mark on the arm of the oil pump, but not sure what it is supposed to line up with. I can see a faint mark up by the word mikuni but no other lines on the pump housing itself. How does this one get adjusted?
Thanks
Mike
Thanks
Mike
I marked them with a black sharpy to give you refrence. The stamped lines should be there. Youll have to clean it off to see.
#4
#5
Thanks for the info,
Unfortunately, the pump lever you have looks different than the one on mine and even after cleaning it up, I only see the one mark. All the other pumps I have adjusted look like the one in your picture, with a mark for idle and another for WOT. I know it does need to be adjusted, since there is some slack in the cable. The pump does work if I run the engine and I pull up on the lever it feeds oil through the line.
Thanks
Mike
Unfortunately, the pump lever you have looks different than the one on mine and even after cleaning it up, I only see the one mark. All the other pumps I have adjusted look like the one in your picture, with a mark for idle and another for WOT. I know it does need to be adjusted, since there is some slack in the cable. The pump does work if I run the engine and I pull up on the lever it feeds oil through the line.
Thanks
Mike
#6
You just may have one of the left over 350 pump and wheel assemblies that they used up if you have just the one mark.I've seen this before. Should have a 38 c or d on the pump wheel for the 400. Critical part is wide open throttle and pump wheel travel. Take the excess slack up on the cable and adjust the mark on the wheel to the the mark on the pump body extrusion. It may be faint but should be right in the middle. Then pin the throttle(secure it or have someone hold it) and see it the pump wheel is close to it's full travel by pushing up on it. If in doubt you can have it a tad rich at idle to compensate for cable stretch over the years.
#7
Thanks OPT,
That would explain a lot. I never checked the pump on a 350 and only on my 400's. This motor is a 94 so I could see it using some 350 leftovers. I will adjust it and see how it goes. The only other oil pump issue I have to work on this week is on the scrambler 400 my daughter just bought. The pump feeds oil like it should but it is leaking oil at the pump somewhere. I'm hoping it is just a bad line that needs to be replaced once I pull the cover off to inspect. I prefer the oil injection over mixing my gas anyways.
Thanks
Mike
That would explain a lot. I never checked the pump on a 350 and only on my 400's. This motor is a 94 so I could see it using some 350 leftovers. I will adjust it and see how it goes. The only other oil pump issue I have to work on this week is on the scrambler 400 my daughter just bought. The pump feeds oil like it should but it is leaking oil at the pump somewhere. I'm hoping it is just a bad line that needs to be replaced once I pull the cover off to inspect. I prefer the oil injection over mixing my gas anyways.
Thanks
Mike
Trending Topics
#8
#9
Thanks OPT,
Its definitely two stroke oil that's leaking. I'm leaning towards the line from the pump going toward the intake is seeping under the cover. It looks like the previous owner pulled the line to move things out of the way when the did the rebuild of the motor. Could have easily stretched or split the line where it goes on the nipple of the pump.
Thanks
Mike
Its definitely two stroke oil that's leaking. I'm leaning towards the line from the pump going toward the intake is seeping under the cover. It looks like the previous owner pulled the line to move things out of the way when the did the rebuild of the motor. Could have easily stretched or split the line where it goes on the nipple of the pump.
Thanks
Mike
#10
Got a chance yesterday to look into the leaking oil pump on the scrambler. After cleaning it up, I noticed it was leaking out of the pump itself by the little plate that is held on by two screws. O-ring was pinched so I replaced all the O-rings on the pump. Sealed it up good when I put everything back together and adjusted the cable. Ran the machine after I bled the pump and it's feeding oil like it should with no leaks. Now I just have to drain the tank full of premix and leave a gallon or so in it till I finish breaking the top end in. Then I will fill it up with a fresh tank of premium fuel. Don't know what kind of oil this guy was running but it's bright red and it's smokey, not like the Polaris blue I'm used to. So many cheap oils out there but I stick with the tried and true polaris stuff.
Mike
Mike