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View Full Version : Oil not getting pumped to the head on ATC 70



MN250R
08-20-2012, 10:40 PM
Well i did a full rebuild since the 70 was burning oil. I installed the 88cc kit from dratv, new valve seals, valves cleaned , heavy duty springs, and there racing cam. Started up fine, ran ok but something wasnt right. Started smoking a little by the top of the engine. Everything was oiled when i put it together. Wasnt making much power, so i toook the engine back apart. Absoulutely no oil in the head, and the passages were completely dry!!!! :wondering. Cam was nice and black from overheating and the outside bearing was dark colored and slightly scored.. Im assuming thats where my smoke was coming from and why it didnt make any power, There was no lubrication up there. The oil pump worked before i did the rebuild. I did clean the oil screen out in the bottom of the engine, and filled the engine back up with oil. Do you think the pump failed? Screen in wrong???Anyway to test if its pumping oil?
Thanks

fabiodriven
08-20-2012, 10:44 PM
I think a more likely scenario would be you may have blocked an oil passage.

atc500x
08-20-2012, 10:50 PM
Normally if you remove the cam cover on the left side(near the spark plug) and you pull start th engine oil is supposed to go thru this passage.
Clutch cover damaged on installation?,oil galery pass thu the gasket,
No oil hole drilled in the 88cc cylinder?
Plugged resctrictor on the crankcase,on the right side,don't remember near upper or lower cylinder stud,under cylinder
Timing chain well installed? the chain drive the oil pump
Bad oil pump....

yaegerb
08-20-2012, 11:40 PM
On a newly built engine its always wise to remove the valve covers and prime the motor to ensure oil is getting to the head. You can also start the engine and wait about 10-15 seconds. Oil should be visible. Hindsight 20/20

MN250R
08-21-2012, 06:05 AM
thanks for the replies! i will look at the timing chain ,oil passages etc.

MN250R
08-21-2012, 10:17 PM
Well, the little hole in the picture was clogged. I unclogged it. Is that a primer hole for oil or some sort? What does that hole do? Is the big hole where the oil gets pumped up?

http://img824.imageshack.us/img824/3433/img521l.jpg (http://imageshack.us/photo/my-images/824/img521l.jpg/)

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Also, the seal cap came in my gasket kit. The green one on the left. Where does that go, i got two of them in a kit that came from DRATV? The other one was a valve seal which i purchased two of them seperately.

http://img703.imageshack.us/img703/9599/img520.jpg (http://imageshack.us/photo/my-images/703/img520.jpg/)

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Thanks for everyones help!

yaegerb
08-21-2012, 10:27 PM
The hole above is an oil passage. The green seal on the left is a valve seal. My 200x seals look exactly like that.