1989 Johnson 200 looper cooling problem

[chefboyrdjr]

purchased an old boat w/ Johnson 200.... after some messing around and new parts got it running pretty good..... out on the water last weekend, runs cool (around 140 to 150) as long as running 1/2 throttle or less..... full throttle it heats up to 170 or 180...... New complete water pump, thermostats are working.... had the lower unit off 3 times to make sure the tube is in the pump and into the grommet...... seems to be low water pressure.... Is there anything that can go wrong where the water tube goes into the bottom of the powerhead? seems like too much water is coming back down the lower unit and out all of the holes in the rear section of the lower.... any ideas? anyone ever run into anything like this? suggestions?

 

[Dhadley]

Re: 1989 Johnson 200 looper cooling problem

Does the motor actually overheat? If the horn isn't sounding and / or the motor isn't going into SLOW (rpm reduction) it may not be overheating at all. How did you come up with the temps? What's the actual water pressure?

 

[chefboyrdjr]

Re: 1989 Johnson 200 looper cooling problem

don't know the water pressure, i do not have a gauge.... the temps are from the temp guage and verified with a temp paint stick - head temps are higher than they should be. water pressure seems low... the telltale seems like a weak stream to me..... It seems like there is a problem with either the water tube or where it goes into the powerhead, but can not see up in there ??

 

[ezeke]

Re: 1989 Johnson 200 looper cooling problem

If you still have the white thermostats, you should replace them with the superseding black ones, part # 0434137, They work better and don't stick as much as the originals.

 

[chefboyrdjr]

Re: 1989 Johnson 200 looper cooling problem

thanks ezeke - is that an i boats part number?

 

[k4ubr]

Re: 1989 Johnson 200 looper cooling problem

How old is the fuel ??? that year tend to run low pressure- is there any leaks around the base of the motor (does the warning horn work?)

 

[chefboyrdjr]

Re: 1989 Johnson 200 looper cooling problem

Fuel tank was recirculated then pumped out - new fuel (premium with 50 to 1 oil mix) - no leaks visible from up top, but as I said it seems like too much water is coming back down the lower and shooting out all the holes in the back of the lower - almost like it it leaking someplace on the bottom of the powerhead? warning horn does not work...

 

[ezeke]

Re: 1989 Johnson 200 looper cooling problem

thanks ezeke - is that an i boats part number?

No, that's OE. The aftermarket Teleflex/Sierra is #18-3500: http://www.iboats.com/Thermostat-Sierra/dm/*******.164296561--**********.721043862--view_id.221731

 

[ezeke]

Re: 1989 Johnson 200 looper cooling problem

................. no leaks visible from up top, but as I said it seems like too much water is coming back down the lower and shooting out all the holes in the back of the lower - almost like it it leaking someplace on the bottom of the powerhead? warning horn does not work...

Normally, water fills the void between the exhaust and the outer exhaust housing while running, drains from the several holes at the top of the gearcase and spits from the exhaust relief. When running on muffs, it appears to be a lot of water spouting out of different holes, but it's normal.

The big bore loopers use a 1/8 inch ID elbow for the tell-tale (overboard indicator) at the adapter plate, but run it out of a 1/4" ID tube at the lower cowl; the resulting flow looks more like a trickle than a stream, but as long as cooling is working, that's OK. If you want to see a stream, you can change the cowl fitting to 1/8" and it will look like a crossflow tell-tale stream.

Disconnect the tan wires at the cylinder heads and ground the control end of the tan wire to the engine block with the ignition on. Be sure that you are grounding the tan wire that runs to the main harness, not the one that runs to the powerpack. If the horn does not sound, test the horn at the control, then replace it. The alternative and preferred solution is to install temperature gauges on both cylinder heads; the threaded holes for the senders are ready in the cylinder heads.

 

[clanton]

Re: 1989 Johnson 200 looper cooling problem

Check the water control valve starboard side of engine. Hoses from thermosats housing and water control valve must be in correct position. Updated thermostat should have updated seat. 140/150 too hot at 1/2 throttle if your gage is correct.

 

[chefboyrdjr]

Re: 1989 Johnson 200 looper cooling problem

Thanks to everyone for the feedback! Is there a thermostat kit with all of the gaskets, stats and seats? - Plan is to put in new thermostats, flush out the engine block while t-stats are out, check the water control valve and hose routing - plan to be out on the water again this weekend - will post an update - I hope she cools better, did not want to have any sustained high RPM runs last weekend because it was getting warm... hope to fix that

 

[ezeke]

Re: 1989 Johnson 200 looper cooling problem

Check the water control valve starboard side of engine. Hoses from thermosats housing and water control valve must be in correct position. Updated thermostat should have updated seat. 140/150 too hot at 1/2 throttle if your gage is correct.

Some of the old seats with the metal holder failed and needed replacement. The new ones don't have the metal ring. Mine never failed, so I still use them, with the black thermostats.

Click the thumbnail twice, please.

 

[ezeke]

Re: 1989 Johnson 200 looper cooling problem

Thanks to everyone for the feedback! Is there a thermostat kit with all of the gaskets, stats and seats? - Plan is to put in new thermostats, flush out the engine block while t-stats are out, check the water control valve and hose routing - plan to be out on the water again this weekend - will post an update - I hope she cools better, did not want to have any sustained high RPM runs last weekend because it was getting warm... hope to fix that

The black plastic thermostat 0434137 is unitized with the spring, cover and vernatherm. The only other part you might need would be the rubber seal.

Check the seats for corrosion and/or distortion.

If you want to update the whole system to 1993 and do away with that weird water control mess, maybe Mr. Hadley will jump in here and give you some help.

 

[chefboyrdjr]

Re: 1989 Johnson 200 looper cooling problem

Thanks Ezeke - The parts diagram shows a multi part thermostat - are you sure the 0434137 will work?

 

[ezeke]

Re: 1989 Johnson 200 looper cooling problem

Thanks Ezeke - The parts diagram shows a multi part thermostat - are you sure the 0434137 will work?

Yes, I have them on my 1990 200 and on my 1988 140.

If you go back to the BRP parts catalog and go to the thermostat in the parts listing, click the magnifying glass next to the part number and see what superseding part number comes up under "equivalent parts".

 

[chefboyrdjr]

Re: 1989 Johnson 200 looper cooling problem

thanks again Ezeke - will let you guys know how it works

 

[chefboyrdjr]

Re: 1989 Johnson 200 looper cooling problem

One more question.... Ezeke, Do I still need the diaphram part # 0394408 with the new style thermostat # 0404137 ?

 

[ezeke]

Re: 1989 Johnson 200 looper cooling problem

One more question.... Ezeke, Do I still need the diaphram part # 0394408 with the new style thermostat # 0404137 ?

Yes, they are a separate item but work the same.

 

[chefboyrdjr]

Re: 1989 Johnson 200 looper cooling problem

ok so I have one more last question. anyone know if i can change the water intake screen without removing the lower driveshaft? I think i will have to pull the waterpump, but hope i do not have to remove the driveshaft. Any help will be appreciated!

 

[ezeke]

Re: 1989 Johnson 200 looper cooling problem

You have to remove the waterpump and the the impeller plate - that's all.

You want that screen to be in good shape because it keeps the junk out of the pump and cooling passages and prevents the blockage in the thermostats that will occur without the screen.