Water pump seal??

[nick790]

I started my EC 250 08' after a top end rebuild last night, topped the water up with coolant while it wa idling, topped it up a bit more, and some more, then notiched it all coming out the power valve breather . Took the power valve cover off to see a steady streem of water coming up the power valve push rod hole .
Am I right in thinking the water pump seal has gone, or could it be something else? Is it an easy job? Does the whole side cover have to come off? What parts to I need and how much?

I've only ridden the bike for an hour, and since then I've had to rebuild the top end and have the barrel replated, suppose to be racing today and now this, I'm starting to loose my patience.

Please help me restore my faith in the Gasser, many thanks in advance.

[GMP]

There has to be a lot of coolant in the transmission for it to be forced up through the PV rod passage, as its on the top of the cases. The pump seal is a possibility as well as the primary cover fit and/or gasket. There are two coolant passages that pass through the cases and primary cover to the pump. What happed that you had to replate the cylinder? Overheat? You have something going on there that you possibly missed.

[nick790]

Yes, it over heated the first time I rode it. I was told that if the engine had water in it, it would pull the plating off in no time? I dont know what happened first.
I'll strip it down this afternoon, and see what i find. I'll pull the cover off for I good look around.

[Eric K]

The waterpump seal is easy to replace.

Drain the coolant at drain screw on waterpump cover.
Remove the waterpump cover.
Remove the impeller.
Remove the seal.
Install new seal.
Some times the impeller will also erode. If it does, replace it.
Install impeller.
Install waterpump cover with new gasket.
Fill with coolant.
Test ride.

I have had the waterpump seal go a number of times. I just replace it and keep having fun. One time all my coolant went into the transmission. The good news was the engine has continued to run great after I replaced the seal. I didn't even lose any top end compression.


Some people have never had any issues with a waterpump seal.

[MattR]

Originally Posted by nick790

...I've only ridden the bike for an hour, and since then I've had to rebuild the top end and have the barrel replated...

I'm curious about the bike's history...
Is your 2008 EC250 a new or used bike?

You indicate that you have only ridden it 1 hour, then had to rebuild the top end and replate the cylinder. Did the engine seize during your 1st hour of use?

[nick790]

Originally Posted by MattR

I'm curious about the bike's history...
Is your 2008 EC250 a new or used bike?

You indicate that you have only ridden it 1 hour, then had to rebuild the top end and replate the cylinder. Did the engine seize during your 1st hour of use?

It's a year old, I'm it's second owner. It's seems it's been massively abused.
Yes the engine over heated and may have seized in that hour. But I know now why...............

Just took it apart, found the impeller in two peices, and the mechanical seal fecked!!! Could'nt get the impeller screw out?? Whats the trick? The water pump drive shaft bearing is a bit nasty too.

So this is what I'm assuming happened........
Nasty cheep impeller broke which bounced and damaged the mechanical seal. Lack of coolant flow caused the engine to over heat and with the added induction of water, drawn in the exhaust port/power valve then cased the plating to be damaged in the cylinder.

What do you think?

Also when I drained the gearbox oil, about 1.5 leaters of water came out, it's a propper mess in there. Whare shoud I go from here?

[GMP]

If its a plastic impeller, it usually takes some heat to make it fail, then it can come apart. In any case, your right, the impellar debris likely took out the seal. Its unlikely you sucked the coolant into the cyl through the exhaust port, it would have to go through the PV bearing. I would look at the head/cyl surfaces for warpage though if the bike did overheat in the past. When you did the top end, did the o-rings come out flat or distorted from heat? Its more common to leak from the head o-rings, and also to pressurize the cooling system forcing coolant out the cap or past the water pump seal. Many different possibilities, one being that it was butchered by the previous owner, Ive seen that more than once. In some cases no maintanence is better.

Flush the transmission out with cheap ATF, don't let it sit with coolant in there. You will need to get it running to do a good job though. Get an alloy impellar, preferably an LTR, seal kit, bearing, check the head and cyl, button her up and you should be good to go.

[MattR]

Nick,

Sorry to hear the unfortunate luck. At least you diagnosed the problem and found the likely cause. Follow what Glenn said and you should be set to roll again. I would also recommend checking the current carb settings and compare to our jetting database. This will give you a decent baseline to make sure it is not running lean the next time you start the engine.

If you have good jetting and a proper flowing coolant system, then you will have happy trails ahead. Good luck!

[nick790]

I ordered the parts today, so should be back on the road soon. I tried to get a aluminium impeller, but as normal no chance of getting any good bits in the uk. The plastic one is cheep enough, and I may take some measurements off of it to see if my dad can make me an ally one up. Unless anyone knows where i can get one in the uk?
I was going to run a couple of leaters of ATF through the gearbox to clean things up, but I've read that some people run on ATF normally?

Any tips for putting it all back together?

[Skidad]

Look on this page link and you will see a kit with an aluminum impeller. It's not UK but is Europe. Nice kit to improve cooling.

http://www.2tracing.it/public/SiTE/i...ts=|divGASGAS|

Many people in the States use ATF in the 2 stroke tranny. No issues and I use it myself.