Update to 1985 150 Johnson rebuild.

[firemann2003]

Found my compression problems. Finally finished tear down and found that 5 pistons had rings that were stuck, very very stuck, and the 6th had a broken ring. Pretty lucky though all cylinder bores are in pretty good shape, no major scoring or scratches. Hope to start getting it put back together this week will keep you posted.

 

[emdsapmgr]

Re: Update to 1985 150 Johnson rebuild.

How badly is the head pitted on the hole where the ring let go?

 

[firemann2003]

Re: Update to 1985 150 Johnson rebuild.

The head was not pitted at all. Took block into shop for boring and mechanic looked at both heads also and said they were in surprisingly good shape, definately needed alot of decarbing though. When ring broke it stayed inside the groove on the piston and did no damage to the bore. Mechanic said it looks as though a good honeing and it should be ready to go, but will have to wait and see what they measure when he is done. Might add I am not useing the same shop that took me to the cleaners the first time either, alot of asking around and I found what seems to be a very reputable mechanic. Two other posts on here are: "1985 Johnson 150hp - Won't throttle up in the water." and "85 Johnson 150, big time help. need to removal powerhead and it is stuck". Figured I would do the rebuild myself after taking it to original mechanic and $850 later I still did not have a boat that ran. They said they checked compression and it was good, that they rebuilt the carbs. and that they rebuilt the fuel pump. Wrong on all three claims. You guys on here have been an invaluable resource for me so far.

 

[emdsapmgr]

Re: Update to 1985 150 Johnson rebuild.

Good news on the ring. Most of the broken rings catch the intake/exhaust ports and wind up rattling around the combustion chamber, damaging the head and piston. Sounds like a lot of carbon on the piston. Common on the crossflows. A can of Engine Tuner through the engine annually is about the only solution. Let us know what the final story is on the piston/liner measurements.

 

[firemann2003]

Re: Update to 1985 150 Johnson rebuild.

Got cylinder block back and ended up boring for .020 over, there was one stubborn scratch in the #1 cylinder (not the one with the broken ring). Figured I would go ahed and bore them all to keep everything the same size. Other than that everything else cleaned up pretty nicely.

 

[firemann2003]

Re: Update to 1985 150 Johnson rebuild.

Assembly went very well. Powerhead remounted and fired up right away, 3 or 4 cranks. Had to shut down after about ten seconds though. Noticed one of the tiny check vavles on the intake got broken off some how and was spitting fuel out, ordered a new one. Pre-mixed fuel in tank just to be sure was getting oiled properly, did not want to trust VRO to pump oil right away after sitting, better safe than sorry.

 

[firemann2003]

Re: Update to 1985 150 Johnson rebuild.

Question - Should this motor, J150TXCOS 1985, have reverse on it?

 

[emdsapmgr]

Re: Update to 1985 150 Johnson rebuild.

If you mean reverse gear, yes. I would run the VRO and premix the gas in the tank-both for the first 10 hours. While it will smoke a lot, it will help the engine break in properly. You can also monitor the VRO tank during that period and check to see that the oil is being consumed.

 

[firemann2003]

Re: Update to 1985 150 Johnson rebuild.

Got the rest of the parts in and installed. Fired right up and is running pretty well. Timing alittle off so did not run it very long. Raining today so did not do link & synch or reset the timing, will do that when not raining.

 

[firemann2003]

Re: Update to 1985 150 Johnson rebuild.

Timing and link & synch. done. Idled for a hour in the driveway, purred pretty nicely. New control cables installed and no reverse is also working. If rain stays away tomorrow gonna try to take the boat up to the lake and see how she does. Not sure if tachometer is bad, it is the original one from 1979 an it is not working at all now, so ordered a new one. Ordered a new volt meter also, in dash meter shows 10 volts but when I check with my multi-meter it shows 12.5 - 13.

 

[firemann2003]

Re: Update to 1985 150 Johnson rebuild.

dipped the boat in the lake today, running really nicely. There are 2 holes on the back of the motor, towards the top of the mid section, just below the exhaust housing. I am assuming those are exhaust holes.? Question is is there supposed to be a small amount of water coming out of those along with the exhaust gases?

 

[Dhadley]

Re: Update to 1985 150 Johnson rebuild.

Yes. That's the exhaust relief holes. Some water will discharge there. Hopefully.

 

[firemann2003]

Re: Update to 1985 150 Johnson rebuild.

guess I should have mentioned that there was some water coming out of those holes. Can't wait to get the breaking period done to see how she runs with more throttle. Did give it alittle more at the dock, but with out tach working I did not want to rev it too much during break in. VRO is pumping oil nicely so when this 6 gals of premix is gone gonna go back to VRO only. Just want to thank everybody again for all the help and I will keep posting as I move onto each step.

 

[firemann2003]

Re: Update to 1985 150 Johnson rebuild.

Well girlfriend wanted to take the boat up to the lake and hear it run, so we did. Started easily, ideled beautifully AND THAN IT HAPPENED. Tried to take the throttle up a bit still ran great, tried to take it up a little more hit 2000 rpm still ran good hit 2200 and it bogged out and died again. Same problem still occuring. Tried pumping the primer bulb and that did not help. Had the carbs rejetted for this altitude, wondering if maybe the shady boat shop I took it to rejetted it wrong. Does anybody know what it should be jetted at? The jets they took out are stamped with "56C" don't know what they put in, but could this be causing my problems? New parts include: VRO pump, fuel lines, fuel filter, fuel tanks, power packs, ignition coils, plug wires, plugs, reed valves, pistons, rings, control box, control cables, primer bulb, carbs. rebuilt and primer solenoid. As far as engine temp. (from other posts I have read) I can put my hands on the heads and comfortably hold them there for about 10 - 12 sec. before the heat forces me to take them off, warning horn does work. Timing set via Joe Reeves WOT method, idle timing verified with timing light. Timing base moves smoothly with throttle. All three carbs. open fully at WOT. All grounds cleaned. Getting to my wits end with this problem.

Original problem posted under post named "1985 Johnson 150hp - Won't throttle up in the water.Update "

 

[firemann2003]

Re: Update to 1985 150 Johnson rebuild.

Compression = 110 +/- a couple of pounds on all six cylinders. Spark test = all six jump a 1/2 gap, bright/blue with a good loud snap. High speed jets removed again and all are clean, stamped with 55C. Local shop says I need to change the prop, currently has 15x17. Could that cause this much of a problem at 6000 feet above sea level?

 

[BF]

Re: Update to 1985 150 Johnson rebuild.

did you follow this thread?

http://forums.iboats.com/bbBoard.cgi?a=viewthread;fid=28;gtid=1183893

sounds similar to your problem... was mixed up wiring for some coils

 

[firemann2003]

Re: Update to 1985 150 Johnson rebuild.

Thought about that one too. Wires from power pack to coils are orange/blue to top coils, orange to middle coils and orange/green to bottom coils.

 

[mikesea]

Re: Update to 1985 150 Johnson rebuild.

Are you positive the carbs are in sync.You loosened the sync screws on the top and bottom carb ,while making sure the middle one was closed ,so that after tightening the sync. screws they all open evenly.

 

[firemann2003]

Re: Update to 1985 150 Johnson rebuild.

yes I did that, twice just to make sure.

 

[firemann2003]

Re: Update to 1985 150 Johnson rebuild.

All electrical parts check out just fine, I am convinced this is going to be a fuel issue. Is there a way to check the pressure at the pulse limiter? It was replaced with the VRO pump, but want to make sure crankcase pressure is enough to operate pump at higher RPMs.