Sophomore
Currently Offline
Posts: 77
A+'s: 0
Joined: Jun 7, 2012 20:55:49 GMT -6
|
Post by jburd on Nov 19, 2012 12:11:31 GMT -6
Here's the background. I have had a lot of issues with my JCL MP250A scooter overheating and I have yet to solve it. I have "burped" it more times than I can count. The coolant level has not changed in the top which to me means I have the air out and am "burping" it correctly. However it stilll overheats. I jumped the wires coming out of the temperature sensor in the bottom of the radiator and found that the fan works fine. I then concluded it's got to be the thermostat or the water pump. I did happen to notice that if I had radiator cap off while it was running, none of the coolant seemed to flow at all even when the scooter was hot. My conclusion was maybe my problem was the water pump. I removed the cover from the water pump to reveal the little propeller inside which at first seemed difficult to turn. With the cover off and the scooter cold, I started the scooter and noticed that the propeller didn't turn at all. If I primed it and started it spinning by hand, it would continue to spin but if I stopped it, it would not start on it's own. First of all, is that normal and am I on the right track? Granted I didn't leave the scooter on very long as I didn't want to overheat it with no water in there. I'm assuming the water pump is my problem. Secondly, I removed the two 8 mm bolts that hold the back of the water on but I can't get the water pump to even budge. Is there some trick to actually getting the entire water pump off? Any help would be greatly appreciated.
|
|
|
|
Post by JR on Nov 19, 2012 17:10:46 GMT -6
First thing is go the the Yamaha section and look at the YP250 Majesty Service Manual; thescooterprofessor.proboards.com/index.cgi?board=ncmanuals&action=display&thread=265Go to page 151 and it gives pictured details of the waterpump andf a break down. Now after removing the 3 main bolts the water pump will come off including the top cap in one piece, you may have to tap it a little to get it to come loose. In the manual page 151 below I've made note of the shaft that turns the oil pump on the right side of the engine by a gear and goes all away across the engine to at the same time turn the water pump. The water pump has a slotted shaft that splines up in the drive shaft when you install it.  For your question of should it turn like you mentioned and the answer is no, it turns as soon as the engine turns over. If not then you've got something wrong as in broke shaft or a bad shaft drive gear? Keep us informed we are here to help. JR |
|
|
|
Post by alleyoop on Nov 19, 2012 17:43:07 GMT -6
BUMMER, Since it appears that you can spin the impeller by hand could be a couple things the Two half lots that are on the impeller are broke or the Male piece that slides in between the two is either worn or broke or the other thing is that the IMPELLER has moved out and not engaging the male piece in the slots.
Alleyoop
|
|
Sophomore
Currently Offline
Posts: 77
A+'s: 0
Joined: Jun 7, 2012 20:55:49 GMT -6
|
Post by jburd on Nov 20, 2012 6:59:56 GMT -6
Thanks guys. This is actually good news to me. At least I know what I need to fix now. I've been stabbing in the dark for awhile. Now I know what to go after and I can soon get my scooter back on the road. I will keep you posted.
|
|
Sophomore
Currently Offline
Posts: 77
A+'s: 0
Joined: Jun 7, 2012 20:55:49 GMT -6
|
Post by jburd on Nov 20, 2012 7:39:30 GMT -6
It took a little convincing but I finally got the water pump off and from what I can tell the shaft going through the engine seems to be fine. I actually started the scooter and ran it for about 20 seconds and the shaft was spinning. In looking at the water pump, what I think is the issue is the impeller seems to be spun off the shaft in the water pump. I can spin the shaft without moving the impeller and vice versa. I think all I need to do is get a new water pump and I'll be back in business.
|
|
|
|
Post by JR on Nov 20, 2012 8:53:10 GMT -6
|
|
|
|
Post by richardthescooter3 on Nov 20, 2012 18:52:55 GMT -6
Good job jburd, hope you get it fix soon (Hey welcome to the forum, your at the right place)  |
|
|
|
Post by alleyoop on Nov 20, 2012 19:28:49 GMT -6
Great!! How is that impeller held on the shaft, welded, pressed or pinned?
Alleyoop
|
|
Sophomore
Currently Offline
Posts: 77
A+'s: 0
Joined: Jun 7, 2012 20:55:49 GMT -6
|
Post by jburd on Nov 26, 2012 11:43:23 GMT -6
Update. Success!!!!!! I got the new water pump installed burped it twice and the fan kicked on automatically. It still seems there is a very slight knock in the engine. It doesn't seem to affect how the scooter runs at all and I can't seem to figure out what it is. It is very faint and I could be imagining it. I figured I would just run it and if it does cause a broblem, I would just fix it if it breaks. Either way I'm excited as I finally get to take the scooter back out on the road today!!!!!!!!!!!!!
|
|
|
|
Post by alleyoop on Nov 26, 2012 12:05:09 GMT -6
FANTASTIC!! Good job, and just think how much you saved doing it yourself, plus the good feeling you get when it all works out.
Alleyoop
|
|
|
|
Post by JR on Nov 26, 2012 15:25:45 GMT -6
Good job!   JR |
|
|
|
Post by richardthescooter3 on Nov 27, 2012 22:23:44 GMT -6
|
|
..BAD TO THE BONE..
