runnin hot - impeller?

graphik · Addict Joined: 20 Feb 2003 Posts: 727 City: miller lake

Hey: Bought a used Tige last September and I did something dumb a bit ago, and now I'm running a little warm. I left part of the cover on the back end while I was idling out. I noticed the temp was up a bit and turned around to see the cover blocking the in take on the back. Not the exhaust, but the one above (air in-take?)
Anyway I think I made the impeller try harder and it blew cause now it smokes a bit, and it runs 20 degrees warmer. When I first start the engine it can run really warm until I start moving.

The question is, can I hold off for a few more weekends, or should I take it in ASAP, to get fixed. I say that cause I'll likely put it into storage over the next few weeks.

garveyj · Addict Joined: 12 Jan 2003 Posts: 877 City: Savage, MN

If it is the impellar, you want to change that right away, as it can just lead to engine damage, and it can cause your belt to sieze up when it goes completely. It does not take long to replace it, so you probably do not need to take it in.

Adam Greer · Posted: Aug 28, 2003 5:58 am Post subject:

If you impleller is going, when it goes its gone. Your engine will over heat quickly and you will pretty much be screwed if you are in the middle of the lake. It doesn't take too long to fix, i would just do it. If you run it too hot you will have to change the oil and everything which will be alot more work than just stickin an new impeller in. Have you ever put a new one in? how many hours do you have.

Adam Greer · Posted: Aug 28, 2003 6:00 am Post subject:

wow, sorry you must have posted that while i was typing......

MrBlean · Posted: Aug 28, 2003 10:28 am Post subject: Overheat

graphik I think you are confusing two things here. The air intake (for the engine to breathe) has absolutely nothing to do with the impeller. That's for your cooling water. I think the two events are just coincidental.

If the engine smokes (blue smoke), that's kinda serious. It means it's burning oil and that means worn piston rings, worn valve guides or some mechanical failure of that sort allowing oil to seep into the combustion chamber (cylinder) and get burnt every time the cylinder fires.

Overheating that goes away when you rev up is, as the others say, probably impeller. But if you've run for any period of time with a dodgy impeller ('cos you failed to notice it) and overheated the engine as a result, it's that which could have created the damage to the motor and hence the smoking.

I sincerely hope it isn't and I'm wrong but your very suggestion of carrying on with a duff impeller doesn't instill me with confidence! A half hour spent changing the impeller yourself (every season) is a very worthwhile investment of your time and a few bucks. Had you done it, it may well have saved you from what might be an expensive repair bill.

Again, I sincerely hope I'm wrong about this.

graphik · Addict Joined: 20 Feb 2003 Posts: 727 City: miller lake

I've done a lot of reading on this site, and know much more now then I ever did about boats. I'm not terribly mechanically inclined, but managed to replace a snapped acceleration cable a bit ago.

I bought the boat, and then winterized it right away as it was too late to use it. I had it professionally done, and was impressed by the work. The guy is great.

As far as signs goes... it's running a little hot. There is smoke when I pull a rider out, but then it goes away. I have no problem getting anything fixed, but as you can imagine, I'd rather have the boat for a long weekend, then have it in the shop. But I also don't want to cause long term damage, or a big bill. I'm by far not rich. I could always change the impeller myself I guess, but I know too, that the smoke is likely not because of the impeller. The impeller, if it is going, will make the engine run hot, but it shouldn't smoke.

Does anyone know what the openings on the back of the boat do? Are they air intake? I have in-takes on the front of the boat, I know that for sure.

I did not know enough to ask if the impeller was changed when I bought the boat. I did plan to get it replaced when I winterized it. I'm just wondering what the problem could be if the holes in the back were slightly clogged for a short time.

Off to the shop I guess.

thanks

Adam Greer · Posted: Aug 28, 2003 11:25 am Post subject:

what kind of boat is it? Is it smoke or just exhaust that you see? I know there are times when i catch exhaust that comes up when you are pulling a rider up. The openings in the back, im pretty sure are vents for the blower. If it is an inboard an impeller replacement is like a 30min to an hour job, assumeing the part can easily be obtained and its anything like my nautique. I can't tell you for sure though....

graphik · Addict Joined: 20 Feb 2003 Posts: 727 City: miller lake

Hmmm. I'm pretty sure that the blower holes is not producing the smoke. I'm confident that it's exhaust, which means that the smoke is coming from within the engine. And the most likely cause of that is burning oil, right? I've got a feeling that I'll have to take the boat in so that the guys can see what size of impeller is being used.

I'll call him now and see what he thinks. Maybe I can avoid taking it in, and do it myself. We'll see.

graphik · Addict Joined: 20 Feb 2003 Posts: 727 City: miller lake

Hmmm. I'm pretty sure that the blower holes is not producing the smoke. I'm confident that it's exhaust, which means that the smoke is coming from within the engine. And the most likely cause of that is burning oil, right? I've got a feeling that I'll have to take the boat in so that the guys can see what size of impeller is being used.

I'll call him now and see what he thinks. Maybe I can avoid taking it in, and do it myself. We'll see.

SupremeWake · Soul Rider Joined: 14 Feb 2003 Posts: 322

Hey man, relax a little and listen to what everyone is telling you. Changing your impeller is a 15 minute job. The only thing easier is changing your spark plugs. You can do it! It is something that you should do AT LEAST once a year anyway. I will now start replacing mine twice a season...depending on how much I ride.

The openings on the back of your inboard are vents for the blower to get gas fumes out before you start your boat. I hope you use the blower before you start it up. The only other openings are the exhaust, which exit under water. Having your cover blocking the rear end wouldn't have done anything to your impeller as Mr.Blean has stated. Its coincidence.

What kind of boat do you have? Which engine?

Here's what you do:
1. Call the marina and ask them for an impeller for whichever engine you have. Look up impeller replacement online and change the darn thing. There is a site that shows you exactly what to do. Go look at this site: http://aquaskier.com/articles/impeller_replacement.htm
It is simple.

2. If your engine is carb'ed, buy some carb cleaner and spray it into your four barrels with the engine just above idle speed. Build up of crap in your carb can cause smoke sometimes.

Don't ride this weekend if you suspect the impeller without changing it. It is easy!

-dan

MrBlean · Posted: Aug 28, 2003 12:56 pm Post subject: Smoke?

Not familiar with the Tige in detail but as Adam says, the vents on the rear of my M/C 205 (just above the rubbing strip) are the exhausts (outlets) for the blower. If it was these you "blocked" with your cover then as I said before, it's completely irrelevant to the overheat and smoking problems.

However, before reading the stuff below, can we (you) check we are talking blue smoke here. Black smoke is an indication of over-fuelling not oil being burned. If your carb is badly set up (assuming you have a carb not EFi) it could simply be a qustion of requiring a tune-up or adjustment of the choke.

If the engine was in a car or truck it would be easier to diagnose. In a car, when you close the throttle and leave the engine in gear so that it over-runs, the wheels drive the engine rather than the other way round. With the throttle closed, the engine is unable to suck as much air in as it needs so essentially there is a partial vacuum created in the cylinders. If the rings or valve guides are worn, this sucks oil up past the rings and down the valve guides and creates lots of blue smoke. Often it's worse when you open the throttle again and the engine fires more frequently burning all the oil thats collected in the cylinders. We're only talking small amounts but compared to what should be there it's a lot. When you see this happening you know you've got a serious problem.

Unfortunately, in a boat, you cannot create the same sort of over-run conditions as the prop slows on down when you close the throttle (watch your tacho for proof) and isn't driven on at the speed in the way that the wheels are on a car.

Blue smoke when you accelerate from a standing start could also be a breather problem (certainly in a car). I'm not sure if boat engines have breathers. In older style cars it used to be a rubber pipe that came out of the top of the crankcase and was connected to the inlet manifold. It's role was to take the hot air and oil vapour that builds up in the crankcase and feed it through the engine so that it gets burned. If the breather gets blocked, pressure can build up in the crankcase and it pushes oil up past the rings in the same way that the vacuum on over-run pulls it up. I don't know if it's done differently in modern engines - I tend not to play with 'em now!

Normally, if an engine is badly worn it smokes all the time rather than just on accelaration. But smoke on acceleration and deceleration is a sign of things starting to go wrong. Mind you, could be ages before it's terminal.

If I were you I'd change the impeller myself and carefully inspect the old one. It will be obvious if there are any signs of wear or damage. If it's OK, then the overheating has nothing to do with the impeller but since you got the thing out, replace it anyway. After fitting the new one, take the boat out and get somebody else to drive it. Have a real good look at the exhaust smoke colour and under what conditions it smokes.

Finally, how many hours does the boat have? You'll see from various posts here, some engines go on for 3000 hours or more. Some people's blow at 400-ish. Much depends on how well they are maintained. When you buy used you always a risk in that regard.