Why is it hot?

St. Louis Dave · **Posted:** Sun May 04, 2008 7:30 pm

I pulled my 260 out of storage today. I hooked up an older Mercruiser muffs to the outdrive of my Volvo and started the water flow. Boat started fine, but the temp gauge pegged to HOT and the temp light flashed. I was getting some water out of the exhaust as I should, but I'm curious by using my older muffs that only flowed water onto one side caused my hot issue. I assume that Volvo requires a full flow of water on both sides of the outdrive for proper cooling.

Impeller was changed just before I sea-trialed the boat. I drove it for 30 minutes in November and then had it winterized so I doubt I have an impeller issue.

Help!

Volvo 7.4 GSI DP

powellcrazy · **Posted:** Sun May 04, 2008 8:03 pm

You are correct that you didn't have a impeller problem last fall, but I bet you do now. It only takes a few seconds of low water flow to the impeller to destroy it. Low water flow and RPM over 1000-1200 will cook a impeller. I know you said that the garden hose was on high, but if the muffs dont seal and deliver water, the motor will be starved.

As the muffs being for a merc vs volvo, I don't think it matters. You have intake grates on both sides of the drive, but they both go to the one and only intake hose through the drive to the impeller.

I recomend getting another impeller, in fact two, a spare for next time.

wkearney99 · **Posted:** Sun May 04, 2008 10:13 pm

Gotta second the idea of the impellers having failed. I always keep spares onboard and rotate them in at the start of the season. You don't want to buy spares, store them and then discover they've dry rotted.

230 Mike · **Posted:** Sun May 04, 2008 10:45 pm

I agree also, but to be safe I'd get a set of muffs that feed on both sides before running the new impeller after replacing it.

LouC · **Posted:** Sun May 04, 2008 11:27 pm

It's hard to say if the single inlet muffs could do that, but usually the first thing you look for with an overheat is the impeller. I use the dual inlet muffs and a 3/4 in diameter hose to make sure the engine gets enough water when running on the hose.
How did they winterize it? Did they use the suck antifreeze up the drive method? If so that could explain it, sometimes engines with an engine mounted impeller will not pull antifreeze the long distance from the lower unit all the way to the front of the engine.

St. Louis Dave · **Posted:** Mon May 05, 2008 8:18 am

Thanks guys. I guess I get my first Impeller lesson this week. I know it's easy, but does anyone have any photo-step-by-step instructions on this Volvo?

St. Louis Dave · **Posted:** Mon May 05, 2008 8:29 am

Found it. If anyone has more/better info, please post it.
viewtopic.php?f=11&t=693&st=0&sk=t&sd=a&start=0

pet575 · **Posted:** Mon May 05, 2008 9:55 am

I'm not convinced that the muffs were the problem, but I also don't have a Volvo. Can't imagine the water requirements are any different. I have a B3 drive and I use the single inlet muffs with no problem. Hopefully I'm wrong, but it sounds to me like there is something more to this.

BrentC5Z · **Posted:** Mon May 05, 2008 10:26 am

How long was it running? It sounds like as soon as you fired it up the hot light came on. Even without muffs, that shouldn't happen. Check the temp wire lead. Also possible, the temp switch is stuck.

captwalt · **Posted:** Mon May 05, 2008 10:32 am

I use single inlet muffs on my Volvo and never seen this.

+1 on the trash the muffs idea.

St. Louis Dave · **Posted:** Mon May 05, 2008 12:20 pm

AFter my journeys today to find a new impeller, I know the muffs are not the problem. The "Volvo" muff kit ($22.99) has only one side of water running. I only had the engine running for less than a minute so I know it didn't get hot. I also am assuming I was getting some water past the impeller becasue I had antifreeze and h2o come out of the exhaust ports. I'll pull the impeller this afternoon and see what's up.

captwalt · **Posted:** Mon May 05, 2008 1:15 pm

You lose nothing in pulling the impeller and it is a rather simple thing to do but I don't suspect that is the cause if you are hot the minute you start up. I am guessing a sensor at this point.

millhaven_nice_guy · **Posted:** Mon May 05, 2008 3:44 pm

Dave
I don't want to hijack your thread but want to ask you a favor... Can you start another thread showing me pictures of the GSi motor? I have the 7.4 in my H260 also but it only has a Gi sticker on it. According to my research they never put that motor in this year of boat. I want to see if yours looks different than mine.

BTW, You may want to take the time to remove the lower half of the rear seating where the cockpit light is. This will give you real easy access to the raw water pump. The ones for our motors are crank mounted

The raw water cooling pump is directly behind that Fourwinns sticker about 12-16" below the lip. The motor takes up almost all the engine compartment so only expect about 4" of fiddling room. Trust me it will be much easier if you take the time to remove this "partition" first. As soon as you look at it you will know what I mean. You may even want to remove the screws from the fuel tank cover and that will definitely give you the best access. I haven't changed my impeller yet but I am going to stop and buy one tonight since my boat is still half apart anyways and it will be easy to change out now.

St. Louis Dave · **Posted:** Mon May 05, 2008 5:15 pm

Yep. I didn't change the impeller today because of the "partition". I don't see how you could possible get your hand under there to change it.

So today I start the boat, and it's not hot. First 20 - 40 seconds guage was pegged hot then it settled down and worked fine. I brought the boat up to temp and the guage worked fine. I'm feeling cool hoses where they should be cool and warm where they should be warm. Honestly, I'm not going to worry about it at this time. (I'll keep a spare impeller though) I shut the motor off, let it cool down and then restarted. No issues. Temp guage works fine.

Go figure.

Marc, I think I have a 2000 engine in a 2001 boat. It does show it as an option on the FW brochure, but looking through the Volvo stuff, it don't see it as a 2001 engine from them. Sorry for the big pix, but you can zoom in to see the GSI logo. Best part about the GSI is the 385 HP conpared to the 330 and 350 from the GS.

St. Louis Dave · **Posted:** Mon May 05, 2008 5:21 pm

Marc, I'm going to hyjack my own thead. Where are your batteries? If you look to the left side of my motor (Starboard side of boat) you can see mine under the step. on the port side of the boat, my trim/tilt pump is sitting in the middle of the nice storage area. I'm sure I can find stuff to put back there, but if they would have put it where yours is, I would have had better storage.

I don't have the FW sticker above the light on the back partition. Do you have a 25th anniversary decal in the center of your helm? I didn't remember this being an anniversary year for FW.

I also don't have the eggshell on my lower hatch as you do. Does it help the noise?

I'll find some more pictures so we can compare. Do you know what month your boat was built? I think mine was built in June.

www.iFourWinns.com

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