2022 Kymco AK550 anti-freeze leak

[Dale]

I bought this scooter new and noticed a small anti-freeze leak. The main tech at the dealer said no problem, that it will happen occasionally also others on the forum had a similar problem. After 2 years and 3000 miles it has grown worse. There is now a small puddle almost every week. It must be coming from the water pump and by now there should be a trail that I can follow to the source. I have no idea how to get to the water pump or how difficult it might be. Even if I can't fix it, at least I'll know what I'm dealing with. Any suggestions!

[rjs987]

If it were just a once in a big while drop on the floor then that is not an issue. I've seen that on more than one bike.
But yours seems to be becoming an issue that should be taken care of. The coolant pump (water pump) is located on the left side at the front bottom of the alternator housing. Because the alternator is dry there are 2 seal bearings on the shaft from the alternator out to the water pump. There is a weep hole between the 2 seal bearings to prevent any coolant from getting into the alternator housing. That is likely where the drip is coming from. Check the bottom directly under the water pump to see if there is any coolant there. The problem is likely the outer seal bearing. Here is a pic showing locations and another link for the service manual that can help in fixing this issue. Download the service manual PDF file for easier viewing. You will likely need to remove the left foot board to get to the water pump even though it somewhat hangs below the bottom of that panel.

https://photos.app.goo.gl/1qTDdGDQe3uLBtqk8

https://drive.google.com/file/d/1M-nAUW1Ay0L6bK50D_EMwYPFT_4-YeDj/view?usp=drive_link

I currently have over 16600 miles on mine in less than 3 years. The only two times I had a very minor drip, at different times, happened within the first 7000 miles. But no drips since. That was 2 years ago.

[Dale]

Thanks Bob, I didn't think anyone would have the service manual on so new a scooter. I already downloaded it and it will take me awhile to understand it all.

[rjs987]

Thanks Bob, I didn't think anyone would have the service manual on so new a scooter. I already downloaded it and it will take me awhile to understand it all.

The AK 550 is not really as new as some think. It was first distributed in 2017 but only first came to the USA with the 2021 model year. I consider this to show how well proven this super scooter is. This service manual was what I could find from the Austrian Kymco head office... www.Kymco.at
Found it in their technical documents download page. There is also a color electrical diagram. I believe both were published for the 2020 Euro 4 model but there is VERY LITTLE difference since then. Nothing significant that I can find. I think last year Cyclepedia published another service manual based on the 2021 or 2022 USA version of the AK. Not sure if it is as complete as the official manual that I have.

Here is a link to my copy of the electrical diagram. I normally have to zoom in to 200% or 300% to clearly read it.
https://drive.google.com/file/d/1M48vAJRF57y060p1fRAHnw0bEhk3DBpd/view?usp=drive_link

[Dale]

After looking at the service manual, I could see this was way beyond my capabilities. Had Sun and Fun Motorsports pick it up and repair it. They also did some annual maintenance. Its a little crowded in my garage with my big lawn tractor and 2 scooters than the car behind them. Maybe I'll sell one, well see.

[robgloucester]

What coolant do you guys use on your ask 550 mine leaked out I want to add more to bring it to the shop it was a green coolant,the manual states to use kymco sigma but I can’t even find the word on google

[rjs987]

What coolant do you guys use on your ask 550 mine leaked out I want to add more to bring it to the shop it was a green coolant,the manual states to use kymco sigma but I can’t even find the word on google

Don't know where you hail from. See if you can find Suzuki coolant. There are 2 types of that stuff. One is the standard coolant for aluminum motors, I think it is green. The other is long life coolant also for aluminum motors and is good for twice as long as the standard stuff. I think the long life coolant is blue. But I may be wrong about the colors. This is what is designed to be used in Suzuki bikes including their Burgman 650. Not much performance difference in the coolant for the AK 550. Should be no problem. Honda bike coolant should also be good. Or Yamaha. Or BMW. They all have the green stuff at least.

[randyo]

personally, I match coolant color at NAPA, they have every color under the sun, that way you don't end up with coolant that looks like mud

[rjs987]

It finally happened with my AK. I noticed a small puddle of coolant under the bike 2 days ago and noticed there was a small drip from the weep hole. This has happened twice before the first year I owned the AK with a lot of time between drips. Just a few drips that are very small are considered normal. Just a few drops and then nothing. This time it was a little more. I looked again yesterday and noticed that there was coolant on the bottom hose that runs from the bottom of the radiator to the water pump and also coolant on the bottom of the water pump. When the temps warm up a bit more next weekend I plan to pull the foot board and a panel or two on the left side to verify what the real issue is. I suspect a loose hose clamp at the radiator. Hopefully that's all there is to the coolant on the hose. I am ordering a mechanical seal and rubber seal that goes between the impeller and weep hole as well as the gasket for the water pump cover. All parts available at TBSS for relatively low cost. The other bearing, between the weep hole and the alternator, should be fine. Maybe I'll also order a new C-clip that holds it all on the impeller shaft. most of those parts are only a few $$. The mechanical seal is not a ball bearing item as many would think but it is a high wear part. It is a nylon/rubber seal. The radiator hose should not be an issue other than the clamp coming loose. That has happened on other engines and vehicles I've had so nothing unusual about that. It happens sometimes.

When I do this maintenance I'll also drain and flush the coolant. It's a little past time anyway. The OEM coolant is the green stuff. I ordered some Honda HP Coolant, blue, from Amazon. Even though it is blue it is labeled as 100% compatible with "original green" coolant. Since I will be flushing the cooling system anyway it really doesn't matter about that last bit.

Flush with 50/50 mix of distilled water and vinegar and run the engine until the fan comes on. Then drain. Then flush with just distilled water only and run the engine as before. Then drain. Then refill with proper coolant. The AK takes a total of 1500 cc of coolant (radiator, engine AND reserve tank). That's just over 50 oz.

[rjs987]

Today was around 60F, just over in the garage. Was colder yesterday and will be colder with rain/snow for the next few days. So I took some time to remove the left side cover, the panel under the left lower foot board. I also removed the left panel floor set, the left lower foot board and alternator cover (these are attached and come off as one part). That exposed the alternator, water pump and outlet radiator hose as well as the bottom of the radiator. I won't need to remove any more panels to work on this issue. One of the things I really like about this Kymco is that the body panels are a LOT easier to work with, remove and replace, than the Burgman 650 I had or any other bike I've worked on with body panels... which is basically all of my bikes since 2002.

I could see that coolant is seeping out around the hose where it is clamped on the radiator outlet. The clamps are good. They seemed to be tight. The hose also looked in good condition otherwise but for the leaking coolant. There is also the coolant drip (very slow drip) from the weep hole at the water pump. This indicates the mechanical seal bearing is worn. I see no other issues that need to be repaired.

I went to TBSS to order the parts. They have all the parts I need. I am deciding to replace the outlet radiator hose, mechanical seal bearing, the oil seal that goes with the mechanical seal, and the water pump housing O-ring gasket. The most costly part is the mechanical seal at $15, then the outlet hose at $8, then the oil seal at $3 and the gasket at $1.50. Total parts cost is $27.50. The bad news is the shipping which comes to $25 resulting in a total cost for parts and shipping of $52.50!!!

Tomorrow I plan to call the Kymco dealer in Iowa City to see if they can ship me the parts and for what cost. I found that there is another branch of the same dealer that is only 53 miles away so I might try there first. The Iowa City dealer office is 125 miles away from me. But the closest dealership is smaller and in a very small town so we'll see. They are all closed on Mondays so I'll call them tomorrow (Tuesday).

In any case, this parts replacement looks like it will be easy enough to do. Since there is a leak I'm not riding until it is fixed, and the cooling system is flushed and refilled with new coolant. I'll be leaving the bits I removed off the AK until then.

[Ruffus]

@rjs987, pls see pic...

for the internal (clued) sealring (red arrow) you would need a long inverted bearing puller (14mm appr), heat it up properly before with a heatgun.

[rjs987]

@rjs987, pls see pic...

for the internal (clued) sealring (red arrow) you would need a long inverted bearing puller (14mm appr), heat it up properly before with a heatgun.

Don't currently have a bearing puller but would this work?
https://a.co/d/hF439Ot

[rjs987]

Bummer.
Just found out that Sun & Fun Motorsports in Iowa City,IA is no longer a Kymco dealer. Will have to go elsewhere for parts or order from TBSS.

[Ruffus]

Don't currently have a bearing puller but would this work?

No, this "legged" pullers do not have enough strenght.  Coz in this filigrane size (10 - 14mm) they would bend. Has to be smtg like att pic..

https://a.co/d/hF439Ot

[rjs987]

So a 1/2 inch (12.7 mm) puller like I posted won't do it?

I did check with the next nearest dealer in Iowa to see what prices they can quote me for the parts. Came out WAY more than TBSS. Most of the parts were more than double the cost. Even though their charge for shipping the parts to me is lower the total cost ended up being a lot more... by about $43 which is a lot considering. I ordered from TBSS. Besides, the "local" dealer said the one more important part I need, the mechanical seal, is out of stock and not expected until sometime in April. TBSS has not indicated but I wouldn't expect them to until they start to process the order. I should get the parts by end of this month. I just need to pick up a bearing puller that will work well without costing as much as all the parts. I don't need the tools for running a shop, just enough to work on this task once in a big while.