'85 XJ700 Maxim X Water Pump trouble

Ok guys, I need your help once again. My maxim x is running hot in the hot weather. Sometimes it runs fine, other times it gets so hot that I have to pull over to let it cool off. I also have a rattle coming from what I've recently learned is the water pump. I'm wondering if this could be the impeller? The rattle is not always there, just sometimes. When it does rattle, it seems to last awhile. When the rattle stops, it doesn't come back for awhile. I'm confused.

Any help would be appreciated, as I do not know much about the water pump on this bike. My service manual is for the air cooled model and doesn't talk about how to check the water pump.

Also, I ride this bike daily to and from work (about 5 miles to and from). Would it do any harm to ride with the rattling until I can fix it?

Thanks.

 

Is your fan kicking on as normal? When cold, have you popped the cap and started it up to see if it looks like the coolant is flowing? Have you flushed the radiator? Have you verified your coolant level by popping off the radiator cap by the gas tank?

Just a few thoughts on some easy checks first. If the rattle is not there always, I would try a few other things before ripping into the impeller.

I had to troubleshoot cooling problems earlier, fortunately, the impeller was not involved.

 

Double check everything JoeFriday mentioned.

But, if it's intermittent that's a bit more odd.

Your thermostat may be sticking (probably my first guess)

The rattle is odd though. The water pump is gear driven off the same shaft as the generator rotor. The water pump has a plastic gear and the drive gear is steel.
There is an inspection hole in the clutch cover right where the drive gear rides. (small round disc with two large phillips screws directly opposite the generator). You can pop that open and take a look at how the two gears mesh together. The cover is sealed with an O-ring so you should be able to remove it and re-install it without creating any leaks.
The drive gear is held on with a simple bolt and behind the gear there is supposed to be a spacer collar. IF the collar is gone, the drive gear can float back and forth on the shaft and cause an intermittent drive situation.
IF that is the case, you probably stipped part of the driven gear (plastic one on the impeller shaft).
You should be able to see when you get the cover off.

Take a look at the online parts diagram for a breakdown if I confused you or drop me a PM and I'll try to email you some pics.
The impeller is molded right onto the shaft and the pump seal rides in the impeller so if the impeller or impeller shaft was bouncing around it would be leaking coolant from the weep hole on the bottom of the pump.

How long have you owned the bike and do you know any of the history?

 

I can tell you about one rattle Maxim-X's are famous for...it's the radiator cover. And you can confuse it with many other things. Sometimes it rattles, other times not. A little weather stripping applied to the cover/radiator in some strategic locations will stop the rattle. Eliminate the radiator cover before you assume it's something else.

 

Thanks for the suggestions guys. First, the fan works fine, but isn't enough to cool the engine while riding. However, with the engine off and the fan on, the engine cools pretty quick.

Second, yes, the coolant is flowing and there is pressure. I have refilled the coolant a couple of times. At first I was refilling the coolant at the cap above the radiator, and I've also put coolant in the over flow tank. But when i put it in the over flow tank, it leaks out the over flow tube that's connected to that tank. Probably put too much coolant in the tank.

Third, I have not flushed the radiator.

I have only had this bike for a year. I tried to pop that cap off that Designer Mike mentioned to see the gears, but had trouble getting it off. I didn't want to force it because I was afraid I'd break something. I can tell it's been off before though, cause one of the phillips head screws has a partially stripped head.

I don't know the history of this bike at all, but I do know that the P.O. did some weird stuff to it. It did overheat on me last summer after I bought it if it wasn't moving, but as long as I was going, the temp would go down. I know in a car that that is a classic sign of a bad thermostat. But now it overheats wether I'm going or not. Also, there was no rattle last summer in the water pump.

It still runs and drives great, except for the overheating here and there. What's weird is that I rode it all day Saturday and it tried to overheat a couple of times, so I checked the coolant level and it looked like there was no coolant in the bike. So I bought some and added it. It then ran hot, but did not try to overheat. It would get close to overheating and then start to cool off. So I thought it was just the thermostat being lazy until I started hearing the rattle coming from the water pump. Now I'm concerned that the water pump has gone bad, and maybe the thermostat too?

 

Thanks, but I'm sure it's not the radiator cover. You can distinctly hear it coming from the water pump. And if you put your fingers on the water pump cover, you can feel vibrations that match up to the sound of the rattle. I fear something in there may be spinning loosley or something. But that is just a guess because I don't know exactly how it works yet.

As I rev the motor, the rattle revs too.

 

Fan should cool it down once it kicks on. If that's not happening, Designer_Mike's idea about the thermostat is a good one to check. A royal pain to replace though.

I have a back-up thermostat I got from O-Reilly. It's the motorad that www.maxim-x.com did a study on. It's under the name Murray Ultra, and PN is 15860. I think it was around $10, so it's an easy test. However, be very careful opening the housing. If you tear up that o-ring, you've got an issue.

 

This is easy to look at...more difficult to fix if this is the problem.

Here are some pics of the access hole to see the gear drive.
http://s288.photobucket.com/albums/ll16 ... rpump2.jpg

And the plastic gear on the water pump.

http://s288.photobucket.com/albums/ll16 ... ction=view¤t=pumps.jpg

If you take the bolt out of the steel gear, there should be a space collar behind it.
It's part number 39 on the parts diagram.
http://www.keystonekawasakiyamaha.com/f ... 5&fveh=124

 

Thanks for the info, I could only find a thermostat for $44 at bikebandit.com, so your $10 one beats it big time. I will look for it.

The thermostat was my first guess too, but it doesn't explain the rattling noise in the water pump... unless there is no water getting to the pump because the thermostat is sticking... then maybe that would make it rattle? Hmmmm.

 

Maybe it is cavitating. That's a pretty wild guess. You've got directions to also do an inspection. Let us know how it goes.

 

Thanks Designer Mike, but the first link didn't work for me.

 

Should work now.

 

Thanks Designer Mike! It looks as though it might be the water pump drive gear that is rattling. That is where the sound is coming from.

 

If that's the problem....it will be a PIA to fix
Not hard, just a hastle.

You'll have to pull a bunch of the cooling tubes apart, and the one on the back of the water pump tends to get seized into the housing. If that one would come apart it will save you some work.
BUT...once you go this far, you might want to replace all the (23 yr old) O-rings on the cooling system with new ones.

 

On the o-ring note Napa has a metric o-ring kit(at least the one near me) that had the proper size o-rings for the larger coolant tubes. I had a leak after doing the valve shims on my x I think they cost 30 cents or so each. By kit I mean a drawer they pulled out and we matched the o-ring up and only had to buy what you needed not the whole thing.

 

I picked up a 419 pc metric o-ring set. It has more than paid off so far.

http://www.amazon.com/gp/product/B0002K ... oh_product

 

Ok, so here's what happened today, and what I think may be going on. When I took the bike to work this morning, the rattle was there. When I left work this morning to go to a dr. appt. the rattle was there and the bike dumped a little coolant on my shoe. Then it sat for about 3 hours. When I started it back up to go back to work this afternoon, the rattle wasn't there and the bike cooled off while driving like it should when it got hot (needless to say I was happy). So then it sat for a couple of hours. When I fired it up to go home for the day, there was no rattle (happy again). I stopped on the way home at the grocery store. When I left the grocery store and fired it back up, the rattle was there (not happy).

Being that I was frustrated with it, I reved the bike up a lot. What I noticed was, that it sounds almost like the plastic water pump sprocket is getting stuck, and the metal one is turning. Therefore, perhaps, the sound of the rattle could be the sound of the metal sprocket hitting the plastic sprocket or the metal sprocket is hitting the side of the plastic one causing it to hit the cover. Perhaps the metal sprocket catches the plastic one just right and gets the pump to work sometimes, and other times it does not. It could be a spacer issue like Designer Mike has said, but why in the world would it start having problems now after a year of working if it was the spacer? Hmmm. I am planning on giving it an oil change this weekend, so when I have the oil all drained out, I will take that cover off and have a better look. I will post what I find for other fellow Maxim X bikers.

 

The spacer collar is a bit thinner that the width of the plastic gear, so if the gear was as far as possible from alignement, if the plastic was in good shape it would still drive the pump, but as the gear wears you get less and less engagement and with any gear that starts to strip, it only gets worse as it wears.

When the bike it "rattling" and running hot, check how hot the radiator is.

Then the next time you get a rattle-free ride, check it again. If the pump drive is bad, the rad should be cooler when your engine is overheating than when it is running at normal temp (due to lack of high flow).

That cover should come off easy, just don't strip the screw any more. You'll need a big fat phillips for it!...and it wouldn't be a bad idea to use an impact driver

 

No problem getting the screws out, I've got the right phillips for that. Once the screws are out though, the lid seems glued on. I tried prying it, but I didn't want to break anything so I gave up.

As of now, the rattle is there, but not as loud. In case I do have to replace that plastic drive sprocket, I'm assuming it won't be too hard.

 

There is an o-ring on the inside. So, you'll have to pry hard enough to get it to unseat.

I haven't had to replace it, but DesignerMike reported the replacement to be a PITA.