I wanted to start a new thread this year, so, here we go.
We found several issues on new customers boats when we winterized their boats for them this year, it amazes me that whoever worked for them in the past never mentioned any issues.
This fall and winter I have already resealed nine lower units that were full of water, on one of these motors which is a Johnson 175 also had a really high idle issue.
The trigger was bad as was the power pack and it would not kick out of fast start, while I had it running it also had a water leak that was spraying all over the lower port side cylinder head.
I wrote an estimate that totaled over three grand and was told to fix it, I removed the power head to access the exhaust cover and found this, take a close look at the center of the pic, that is a block exhaust stuffing box, see where the bar in the center is burned through??
Ya, that box separates the three cylinders in each bank, with it burned out like that it severely affects the tuning on those three cylinders!!
300 worth of parts, 250 bucks for match machining the new ones, and the powerhead is ready to go back on and then we will finish the rest of the job.
I had a new customer from NE Iowa join IDO to contact me about a problem he was having, I gave him my cell number and we set up a date to come down for a look see.
There is a long story here but I am just going to cover the bases, in short, the thing wouldnt run and had no top end power.
When Craig dropped it off I did a fuel pressure test, it was at minimum specs but it held steady, knowing the yamaha powerhead on this motor I removed the injectors and sure enough, all four dribbled, they dribbled at 10 psi and they dribbled at 42 psi.
No two of these injectors would flow identically using my old school way of testing them, after many and I mean many hours of cleaning they would not come to their milk.
I checked the fuel filter also, and according to Craig it only had a few hours on it, I took it off to find it absolutely plugged so tight my shop air at 160 psi would not blow through it either direction.
Out of curiosity I tried cleaning it and got this out of it but still couldnt blow through it even with a can of brake cleaner, I capped it and filled it with Neutra 131 and let it sit overnight.
The next morning I drained it and could blow through it in one direction only, but at least I was gaining, ( mind you, I do not use filters over but I had to know what was going on ).
I cut it apart and discovered what was happening, the filter itself missed being sonically welded and when it plugged that debris in the one pic got around it and took out the pump and injectors.
When I tried blowing it out backwards the filter end cap would effectively block the inlet side of the filter body acting like a check valve, and no, this is not an intended design.
A bunch of time and dollars later I made a pull on the dyno, ran great !! but at around five grand it nosed over and just started acting like it had lost its mind, you could see the pressure surges on the dyno and I shut it down.
I spent a ton of time trying to figure this thing out, finally I caught the throttle position switch failing right at 4800 rpms and I mean it was all over the place!! 0 volts to 5 volts and anything in between !! the poor ECU didnt know whether to fish or cut bait !!
The TPS would only act up when it had a bit of heat built up in it, more money!! but not terrible.
I had Craig come down and we ran it on the dyno for him, I think he is going to find that this motor had been ailing for a long time and didnt realize it, however, with ice on the rivers I will wait until he can wring it out and report back.
I gave him my word, and you are reading it here in type, if he aint happy I will make the three hour drive northeast to see what is going on.
1975 Johnson 25 tiller, guy brings it in and just drops it off unannounced, can ya maker run Doc??
Well, ya, I can, whats the dollar limit?? well, I want electric start on it, tuner up, replace the impeller, service the lower unit and what ever else it needs, uh, yeah.
I ask, do ya want me to call you if it gets over five hundred? I mean the thing is fifty years old ya know, nope, just fix it and I aint got twenty three hunnert for a new one, oh boy here I go again!!
SO,,,,, head gasket is blown on one side on the bottom cylinder, on the other side on the top cylinder, ( see pics ), install electric start kit and cables, water pump kit, service the lower unit, two spark plugs,, like The Famous Grouse always says, you just cant kill an old OMC motor and this thing runs sweet, it ought too, nine hundred bucks later and most of that is wrapped up in the starter kit.
Oh, before I forget, the head was warped ten thousands, ten minutes on a piece of countertop and sixty grit sand paper we had a flat head again.
Attachments:
Johnson-175-exhaust-stuffing-box-scaled.jpg
blown-here-too-scaled.jpg
25-Johnson-head-gskt-scaled.jpg
goo-out-of-filter-scaled.jpg
bad-filter-scaled.jpg
