Bad Water pump?

[Russ]

Ok, so after many trials and tribulations, i finally got the old beast up and running. However now I'm having some heat issues. Went for a 100 mile shakedown ride after I got it back together, and everything was fine. Rode it 50 miles into work that night, did fine until I got into town. stopped at a stop light, and noticed the heat guage creeping up. took off from the light, and it dropped (and I mean dropped, like split second went from bottom of the red to middle of the green). It did fine rest of the way to work. went to come home sunday afternoon, it did just fine until I got onto the highway. Guage creeped up to the red again, and just stayed right at the bottom of the red. Pulled over at an exit ramp, waited it out for a bit so it could cool off, got back on the highway, just fine for another 20 miles, guage goes back up to bottom of the red. Leapfrogged it the rest of the way home. Thermostat was replaced with the NAPA 156 two weeks ago (gasket fell apart in my hand, had to RTV the housing, new gasket and o-ring are ordered and hopefully will be here tomorrow). Does this behavior indicate the water pump is going out? If so, anyone happen to have one they want to get rid of? I can't seem to find it on the parts diagram, and I'm really hoping it's not going to be too big of an ordeal to replace.. been without my bike for two years, really don't want to spend another summer wishing I was riding.

 

as an afterthought I looked in the classifieds and saw there's a water pump out of an '84.

http://www.venturerider.org/classifieds/showproduct.php/product/2071/cat/6

any reason why this wouldn't work in my '86?

[Dano]

Most of the time hot running while moving is a carb synch issue, and if you're at a light the lack of airflow thru the radiator will cause temps to go up.

Did the fan kick on when you were at the light? ( Should come on as the needle moves into the red)

Did you change and top of the coolant after the thermostat change?

Did you reset the drain valve to the off position? (Black knob under the radiator, the off position is 2:00 as you're looking at it.)

Check your plugs to see if you are running rich (black deposits) or lean (white tips). This will give us an indication of how your motor is running.

Clean and re-tighten the connectors under the bottom of the right fairing where the temp sensor is located, there is a separate ground that hooks up there. One of the round connectors could be loose, causing the fan to not come on or the gauge to work improperly.

 

Let us know if this helps.

 

Dan

[Russ]

I'll double check the drain valve. I thought that's where I set it, but I could be wrong. I know I need a carb sync, and yes, it's got fresh (and topped off) coolant. Fan did kick on, but i'm going to have to check those connectors. I had so many things on and off the bike the past two years that I could have taken it off and not re-tightened it.

[sarges46]

If it stays at the bottom of the red then that would be pretty normal for stop and go riding with the 1st gens. Mine did that and I dont believe I've seen one that hasnt crept up to that line. If it crosses then there is a problem.

 

As mentioned, the fan should be coming on at those times. Flushing the rad etc is all good maitanance but even after all that mine still went to the bottom of the red when not moving.

[ddoggma]

My 88 will creep up to the top of the green in stop and go. when its hot out. But its never over heated...yet. From what I have heard, it's normal for them.

 

 

Ride on...

[jasonm.]

there is no reason to replace the whole pump. The pump is rebuildable. And only rebuild it when you see or smell coolant coming out the weep hole on the bottom of the pump. ONLY the seals , bearing , orings, impeller and gasket would be needed. $80 in parts. ALso you MUST check the coolant at the reservoir in the fairing. Should be close to half full when cold. And level will rise when hot. Mine runs to 1/4" below red if I let it then the fan kicks in. But I have a manual fan switch. Which ends worrying about over heating. I suggest you only do the rebuild w/manual in hand. Lastly the mechanical seal and other part prices vary. One stealer wanted $21 for the mechanical seal. I got it for $14 from the dealer I usually go to.

Edited May 28, 2009 by jasonm.

[Russ]

I don't suppose anyones got a picture of exactly where this weep hole is?

 

I checked the coolant levels, checked the drain valve, checked the wires. Fan is kicking on. got on the bike tonight, let it warm up for about 5 minutes before hitting the road, 5 miles and needle was on red. 6 miles and it was in the red with coolant audibly boiling in the overflow bottle.

[Neil86]

With engine cold check the actual radiator fluid level....it has to be full for the overflow tank to operate correctly, the full rad overflows to the tank hot, siphons back cooling off so rad remains full.

As mentioned ensure drain valve is in the off position. The weephole is on bottom side of waterpump at ~ 7 o'clock position as you face the cover of the pump.

[Dano]

Sounds to me like you might have a blockage in the coolant stream; or for some reason, the flow at higher rpms might be collapsing a hose. If it heats up that quickly, the coolant definately isn't flowing.

[Venturous Randy]

I have also heard of the tube that goes across the front of the motor getting clogged up. If I were you, the next thing I would do is turn the bypass valve to the on position and see if it makes a difference. It may help you isolate the blockage if there is any.

RandyA

[jasonm.]

I don't suppose anyones got a picture of exactly where this weep hole is?

 

I checked the coolant levels, checked the drain valve, checked the wires. Fan is kicking on. got on the bike tonight, let it warm up for about 5 minutes before hitting the road, 5 miles and needle was on red. 6 miles and it was in the red with coolant audibly boiling in the overflow bottle.

 

HAving a bad radiator cap can also make it run hot. You MUST have pressure in the system for proper cooling. A bad cap will release pressure too early. I believe a generic cap- Stant 227 will fit.

Weep hole- Look up under the engine guard. The weep hole is @6 o'clock. Aiming slightly to the rear. All engines have or should have some sort of weep hole.

Russ, you have a 1300. Then you won't have issues with the impeller failing(breaking). But If the seal does leak. ALL items I listed earlier should be replaced.

[Gearhead]

The gurgling, "in the red" thing sounds like you are overheating for real of course. But just to clarify what you can expect, on my 87, the fan comes on just a bit below the red, maybe 1/16" to 1/8". Under ideal conditions the bike runs just under the halfway mark where there's a gap in the green. But it seems that the radiator is just a bit on the small side, or airflow to it is not what it should be. I say this because:

 

- The "halfway mark" only holds at a nice cruise, say 45 or 50, on slightly warm days, or if the weather is cool it will cruise on the Interstate at that mark.

- If I'm at Interstate speeds (significant engine loading) on a warm or hot day, the temp creeps up, often to the point of the fan cycling. Seems weird since natural airflow should be max at that point, but I wonder if the front tire and fender "split" the airflow around the radiator (I've heard of that on other bikes - Virago's run cooler on rear cyl than front for that reason). Maybe that's why Yammy designed those little scoops on the sides of the radiator grille.

- In traffic, unless the weather is really cold, it warms up above halfway.

- It almost never goes above the "fan-on" temp. This tells me that with proper airflow the radiator is up to the job. Once, when traversing the southern CA/AZ desert 2-up at 107 deg F (not fun), and making time at 80-90 mph, it went a little higher, flirting with the bottom of the red. FWIW, it also got 26 mpg - ouch. But even then the temp, while on the high side, stayed under control.

 

All these things are normal according to everyone here. I'm told each temp gage responds a little differently, but the patterns are common.

 

Assuming you are actually overheating:

 

- Have you totally flushed the cooling system, including the radiator, block, etc?

 

- You can remove the water pump cover to inspect the impeller. Not a likely problem. Early bikes had a plastic impeller that would break, but I think yours came with a metal one. If you do this, have a new cover o-ring-gasket on hand.

 

Good luck.

 

Jeremy

[jasonm.]

Gearhead...your bike needs a tune up. I went across deserts of CO. and Utah pulling a trailer no mods to the engine. Mine never ran or runs that hot at hi-way speeds. Went across NE. at 85mph. Still cool runner at a air temp of 90. I would also recommend you remove the thermostat and turn the screw in the middle clockwise a couple turns or till flush. This lowers the opening temp. to as low as 165. I did this to mine about 8 years ago.