Outboard overheating at idle

[Pink Pounder]

My 1998 yamaha 130 overheated the other day while running on the muffs at and idle. Water was coming out of the tell tale hole but wasn’t warm at the time of overheating. Could it be a bad thermostat? Water pump deteriorating and not supplying enough pressure? Thanks

 

[scott craven]

I don't think the muffs always provide adequate flow.
I had that happen before, If you can hold your hand on the head
for 10 secs and there's no steam from the exhaust, you're not overheating.
check the intake screens for crap

 

[Pink Pounder]

I don't think the muffs always provide adequate flow.
I had that happen before, If you can hold your hand on the head
for 10 secs and there's no steam from the exhaust, you're not overheating.
check the intake screens for crap

I should’ve stated that the high temp alarm did go off and there was steam coming from the exhaust

 

[scott craven]

Could be time for a water pump
Impeller change.
Have you sea trialed ?

 

[Pink Pounder]

Could be time for a water pump
Impeller change.
Have you sea trialed ?

I have not tried sea trialing yet since this issue started. Do you think it’d be worth doing before going ahead and replacing the water pump/impeller? Thanks

 

[scott craven]

Yes especially if it hasn't been done in a while

 

[profisher]

Get one of the cheap digital handheld temp guns..Crappy Tire has them, they work well. Same as the ones used to test your temp for Covid. Point at the t-stat housing and check...that will confirm or not if you are getting hot.

 

[Derby]

Impeller

 

[trophywife]

salted up t stat , or a piece of impeller may be stuck in the system. compressed air works great for blowing crap out.

 

[Oceanmaster]

For some reason Yamaha’s seem to throw the overheat alarm running on muffs alone, even with a good pee stream .If you use muffs and the flushing attachment it won’t happen.

 

[Drink]

I would lean as mentioned to the impeller first particularly if it hasn't been changed recently.
Don't overlook the plastic impeller housing as well as mine that was the culprit. Impeller looked ok but the inner housing showed a little roughness and burnt marks. If you decide to replace the impeller in my humble opinion do the full kit as you are there anyway. Piece of mind. $100 well spent.

 

[profisher]

Are you sure it was overheat alarm and not low oil in the under engine cowl oil tank? Assuming its a 2 stroke being a 1998

 

[salmonkiller01]

I would change water pump (complete kit with housing) and replace thermostat. Good maintenance If you still get the alarm you have eliminated two important parts of the cooling system.

 

[Pink Pounder]

Are you sure it was overheat alarm and not low oil in the under engine cowl oil tank? Assuming its a 2 stroke being a

I did check the oil level and it wasn’t low. Thanks though

 

[Pink Pounder]

I’m thinking I’ll go ahead and replace both the water pump and thermostats. It’s a new to me boat and I can’t find any indication that either have been done recently, when looking through the maintenance records

 

[gungadin]

As the maintenance of the engine may be unknown to you, I would inspect the internal anodes if any, for being eaten away, especially if the engine was run in salt water.

 

[baddogg]

Personally I would drop it in the chuck and idle it up at the dock and see if the same symptoms show up. Maintenance is a good thing but changing things just to change them doesn't make sense to me. For the time it takes to try that you may save yourself a buck or two. I understand that peace of mind is a good thing, but if it doesn't exhibit the same signs when in the water then more than likely an issue with the flushing system.

 

[Sea Chaser]

I had my Honda 90’on the muffs about a month ago and the high temp alarm came on. Took it out on the chuck last weekend and it was fine. Went fishing for the day. Might be worth a shot. But again I hear you with the peace of mind knowing the parts are new and for you to keep a good maintenance record .

 

[CIVANO]

run it in a stock tank

 

[searun]

As the maintenance of the engine may be unknown to you, I would inspect the internal anodes if any, for being eaten away, especially if the engine was run in salt water.

Roger that, I change mine out every season. You would be surprised at how much wear they get. Mind you I put on 400 hours/season.