400R V10 Sportmaster Water Pump

[Taylor]

Serial # 3B538624

I have a new V10400R with the 1.6 Sportmaster case with 60 hrs. I’m getting zero water pressure at idle with my jackplate raised (cavitation plate at waterline), so have to lower it to avoid temp climbing which makes it hard to idle out of shallow ponds. Runs ~20 psi at WOT. I was planning to change my water pump impeller, but the impeller itself is showing $180 with baseplate another $120. I think the 450R impeller is $30, so wondering if I’m missing something or if there’s a reason this water pump is so expensive.

[EuropeanAM]

Totally different water pump.

I would recommend you simply buy Part# 8M0199856, which includes the plate, gaskets and impeller in one kit (cost effective).

[Taylor]

Thanks Don, I didn’t see that kit originally. Do you use Perfect seal on baseplate gasket on the V10 also?

[River Rocket]

I had this same issue with the 450R all the time. I had to keep the lower low or it would overheat.

[EuropeanAM]

Thanks Don, I didn’t see that kit originally. Do you use Perfect seal on baseplate gasket on the V10 also?

I would recommend it.

[EuropeanAM]

Might also want to check your thermostat- look at the number printed on the end of the thermister (should be 059T). If not, an updated thermostat is available under Part# 8M0222328

[Taylor]

Totally different water pump.

I would recommend you simply buy Part# 8M0199856, which includes the plate, gaskets and impeller in one kit (cost effective).

Is the water pump issue something that would typically be taken care of under warranty or is it not likely? Just debating whether it’s worth bringing to dealer and the downtime vs just doing it myself.

[EuropeanAM]

Water pumps are considered a maintenance/wear item. The only exception would be in cases of a defective component (which is rare, but does happen).

Thermostats are the same.

[Taylor]

Changed water pump. Old pump was in great shape. Does a bit better at idle now but temp still fluctuates between 145-168 deg at idle. Seems to work better if you rev up engine and then start idling. Wondering if it might be a poppet valve leaking. I noticed a small spray of water on port side. Any ideas? I haven’t taken side skirt off yet to check. IMG_5664.jpeg

[Capt James]

You've got something else going on there and losing water pressure, nothing should be leaking out of that area. I've heard the V10's and 450's need to be a little lower at lower speeds........168F though shouldn't hurt anything at under 1000 rpms........that's a normal temperature for a 4 stroke.........

[EuropeanAM]

I'm going to be running a couple of these soon... I'll try to make note of what might be going on there.

I can tell you that temp range is within acceptable limits... and it's actually a very GOOD thing that the engine is getting up to temp at idle (in the past that has been a challenge on some other models).

[rocketmanjp]

Is the coastal flush port connection near there that could be leaking/cap not screwed on tight?

[Taylor]

I’ll pull the side panels off tomorrow and see if I can figure out where it’s leaking.

[EuropeanAM]

There are a number of cooling system discharges beneath the lower chaps, most of which cool the exhaust, midsection, and oil sump. This is likely what you are seeing (if you strip one "naked" and run it, it literally "looks" like it has leaks all over the place. And it MUST be this way or the exhaust would melt down.

[Taylor]

IMG_5687.jpegIMG_1215.jpegIMG_1218.jpegFound the culprit today. Took the side panel off and water was shooting upwards through this red gasket that appears to have pushed out. I had the boat over the water so didn’t take anything else off for fear of dropping parts in the water (had already dropped a rubber grommet). Not sure what this part is but it’s behind the circled area.

[EuropeanAM]

Appears to be the relief valve cap. That should be taken care of under the Factory Warranty.

BTW: You also have an outstanding Safety Bulletin: SB 2025-005 (Dealer should be able to address this for you while it's in for the seal on the relief valve cap).

[Taylor]

Yes, seal was blown out. Found a replacement so will fix today. 80 cents so not worth taking in. Thanks for heads up on bulletin

[EuropeanAM]

That particular one (Bulletin) is one I wouldn't wait a long time on. Most dealers can complete it in 10 minutes.

[Taylor]

Seal replacement fixed my issue. Runs 140-142 at idle even with jackplate all the way up and 153 deg at speed.

[mactlman]

Seal replacement fixed my issue. Runs 140-142 at idle even with jackplate all the way up and 153 deg at speed.