98 Johnson 175 Faststrike 175GLECD loss of power issue

[swvabassangler]

I have 98 Triton TR-19 with 175 Faststrike that i have owned almost 2 years. The engine had done fine till few months ago when i noticed i lost some top end speed. When i first got the boat it would run about 56mph with tournament load, half tank of fuel and partner. About a month later i noticed i was only getting about 50mph. Then it gets worse from there. It seemed like each month it got slower.. It was idling and getting on plane fine but just no top speed. Last month it got worse and started to cough or hiccup at idle,was missing while getting on plane and top speed was 43mph. I could smell gas when it done this. I checked plugs and the bottom left one on the passenger side was solid black and the others was in rough shape but not nearly as bad. So i replaced the plugs and plug wires since they was old. I also noticed that my car bowls was wet with gas. So i replaced the bowls with new and made sure to put the orfice back in. I let it run some on muffs and checked the plugs and they all looked good. I took boat out and it idled fine and got on plane fine but only would go 43mph. As day went on the idling started getting worse and slower getting on plane. So after fishing for half day with a few 5 to 10 min runs i loaded it up and brought it home. I checked the plugs and the bottom left was black again. All the other plugs was fine. The previous owner "said" he had carbs rebuilt right before i bought and it looked to be true when i put the bowls on. Thinking it was coil or carb, i done some switching. I took bottom carb and swapped it out with middle carb, i also took the bottom coil pack and swapped it out with the top coil pack to see if it fouled a different plug this time. I put new plug in the bottom cylinder and took her out today. At first it idled fine and jumped on plane but same thing, only 43mph. As the day went on it started missing getting on plane and sometimes had rough idle. But then sometimes it would straighten up and be fine idling and getting on plane but never no more than 43mph. I brought it home and done compression check. My gauge is very old and cheap so i dont know if numbers are exactly right but top 2 cylinders on each side showed 90lbs and the bottom one on each side was 79 or 80lbs. The tach shows about 5000rpm full throttle with 43mph but seems like i can get 43mph at around 3800rpm. I did push in the choke while trying to plane and it got worse. Sometimes today it idled ok and planed fine and other times it was bad. The VRO is deleted and i mix my fuel 50:1. I also check the timing arm on top of the engine and it was correct. What do i need to check or do next? Any thoughts and help is very much appreciated. I also attached picture of the plugs which are champion ql78yc gapped at .30

[ChampioNman]

What were the middle two cylinders numbers?

[swvabassangler]

Middle two cylinders was 90lbs as well. I also replaced the theromostats, thermostat springs and put new water pump in last summer.

[swvabassangler]

So i went to local advance auto and purchased ignition tester. I checked spark on all 6 cylinders. I attached image of where i set the gap on the tester(so you guys to see if that is where i should set it). Each test was with about a 3 second crank time with no plugs in the motor. The 3 cylinders on the drivers side had very good and fast spark. I could hear it and see it good. Now the top cylinder on passenger side had spark but wasnt going near as fast as the other side and had lighter color. The middle cylinder would only spark a couple of times during the 3 seconds, had lighter color and i couldnt hear it. The bottom cylinder was about the same as middle with 2 sparks, couldnt hear it and lighter color. Had wife crank boat while i looked then i cranked boat while she looked. I could hear the drivers side spark while i was cranking but never heard the passenger side. Weird thing is only the bottom cylinder spark plug was only one black. Middle one looked good and it has about same spark cranking as the bottom. Is the way i done the test enough to say it has weak spark on passenger side? If so what do you guys think i should check next?

Update: I moved the gap on the tester to be as close to 7/16 as ii could. The spark on drivers side was same on all 3 cylinders. The top and middle cylinder on passenger side got faster but was still not the color or sound of drivers side. The bottom cylinder on passenger side was slow and even dimmer of spark than top two.

[swvabassangler]

Update: So while checking engine on muffs i noticed that engine was not coming out of "Quickstart" and staying at about 1200 rpm. So i replaced the temperature/quickstart sensor. I also put in new stator, powerpack, optical sensor, new fuel line from tank to motor, throttle roller (mine was broke) and 3 more carb bowls. I have good spark on all cylinders now. And new spark plug in bottom left cylinder. All idle screws on carbs are adjusted out 6 turns.

I took boat out today and it came out of quickstart and ldled about 800rpm like it should and ran about 46mph today with extremely light load. I ran boat for a few runs over 10 mins long and fished half the day with numerous short trips. It seems that i reach top speed at about 3/4 throttle at 4800rpm. If i push throttle anymore than 3/4 it didnt go any faster or slowe, rpms doesnt change and feels like it bogs down even though speed is same.This time the engine didnt cough or sneeze. It idled fine in gear after a long run but when it sat for a while, it didnt want to idle in gear on start up. It would start to stall out and if i pushed the choke in, then it would idle up normal again then die. I brought boat home and checked plugs. All the plugs looked fine, like brown paper bag, EXCEPT the bottom left plug. This time it was only half black and half white. It wasnt wet though. Seemed like it was maybe carbon build up on it.

Someone told me it could be water blockage in lower unit or blowed gasket causing number 6 cylinder to run cold. Anyone ever heard of that? Any ideas and thoughts are very much appreciated. Just want to get this thing back to normal.

[ChampioNman]

Someone told me it could be water blockage in lower unit or blowed gasket causing number 6 cylinder to run cold. Anyone ever heard of that? Any ideas and thoughts are very much appreciated. Just want to get this thing back to normal.

No gasket to get blowed out on your motor they use O rings on each cylinder. Think about that statement on the water blockage on the lower unit. It would effect all the cylinders. Move your coil packs around and see if it follows. The motor only rotates so fast so the plugs would not spark any faster on the starboard side vs, the port side.

[swvabassangler]

No gasket to get blowed out on your motor they use O rings on each cylinder. Think about that statement on the water blockage on the lower unit. It would effect all the cylinders. Move your coil packs around and see if it follows. The motor only rotates so fast so the plugs would not spark any faster on the starboard side vs, the port side.

Thanks ChampioNman. Will try this and update what happens.

[swvabassangler]

Had some free time today and was checking the fuel system. Still havent got to put it on water with coil packs rearranged but here is what i have found. I took airbox off and pumped up the primer bulb till it was hard. Just few seconds later it would leak down and i noticed air bubbles in the clear connected as i pumped. I could hear air coming from top hose that hooks into the airbox right after bulb got hard. I then noticed some fuel leaking out of carb on bottom cylinder that i have been having problems with. I took carb off and replaced bowl gasket and it stopped. I pumped bulb up again and same thing. Air noise and bulb got soft. I could hear noise coming from vro pump when bulb got hard. I pulled the hose off that goes to the pulse limiter and gas came out. I left hose off and gas came out immediately when i pumped bulb. I put my hand over the fitting on the bottom of vro pump and pumped the bulb and the bulb stayed hard and no air noise at all. Is this normal for fuel to come out of the pulse limiter hose?

[ChampioNman]

No you have a leaking fuel side diaphragm. You can get a rebuild kit for it or opt to go with a Premix solution. But fuel into the pulse fitting is never good.

[swvabassangler]

No you have a leaking fuel side diaphragm. You can get a rebuild kit for it or opt to go with a Premix solution. But fuel into the pulse fitting is never good.

Thank you so much. Gas is pouring out as soon as i pump bulb. I already premix. Do you recommend rebuilding or purchasing this https://www.offshoremarineparts.com/62-13-860.html?

[Kris481VS]

Following having the same exact issue. 45-46 @ 4600rpms

[Kris481VS]

I also have darker plug on #6 cylinder. My compression Johnson 150 FASTSTRIKE GLERV
#1 102
#3 100
#5 100
#2 105
#4 96
#6 95

Starts easy seems to idle fine.
Replaced O rings and decarbed piston.
New t stats

Driving me nuts
Pushed key choke in it dies back likes its gonna flood out. No pick up. Very interested in a fix.

[swvabassangler]

Took the VRO apart and the diaphragms look good. I noticed on the side where gas and oil mixes i had a black bushing and silver washer that fell out. It wasnt the washer or black round piece that held the back of diaphragm on. I pushed the bushing back down in the hole that the tube goes throw and the washer snapped in over top of the bushing. I put it back on and now the leak is fixed. Nothing coming out of pulse limiter hose and bulb gets so hard i cant press it anymore and stays that way. I couldnt find the bushing or silver washer online but i if you pause this youtube video at 2:06 you will see what im talking about.

I will hopefully get the boat on water sunday. Could leaking fuel bad into pulse limiter hose cause loss of rpm and to end like I was experiencing?

[ChampioNman]

Parts are shown in the rebuild kit but it is well hidden, sounds like you've got it figured out.


Kris please start a new thread no Hi Jacking please.

[swvabassangler]

UPDATE:

I took boat out sunday. This time i was by myself and in between half tank and quarter tank of fuel. First run of the day it got to 5000 rpm and i seen about 51 mph but that was it. As the day it went on it was about 45 to 48 mph with top rpm of 4600 to 4700. While running at wot i pushed in the choke and the engine started to bog down. It didnt want to start if engine sat awhile unless i pumped bulb back up. When started it didnt want to idle. I adjusted idle screws and it got better. I orginally had them set at 6 turns out. I ended up at about 8 turns out. Now it starts back fine when its been sitting for a while and idles better in gear. It idled and started back fine the rest of the day. Brought boat back home and checked the plugs. All 6 plugs looked good (like brown paper bag).
I have new coil packs, carb rebuild kits and fuel pump rebuild kits on way. Dont know if that could be it but since i had them apart i figured it couldnt hurt.
So now I have good startup hot and cold, good smooth idling in and out of gear, all the plugs are looking the same after being ran for long time. Everything is normal except WOT rpms and top end.

Is 8 turns out on the idle screw fine?

Any other ideas on what this could be? Could timing or prop/prop to pad cause this?

[swvabassangler]

UPDATE:
Ok i rebuilt carbs, rebuilt fuel pump and put new coils on. The fuel system now holds good pressure with no leaks. I ran it a couple of times on lake and same thing, only about 4800rpms. i switched to 23 pitch prop and it went to about 5000 rpms but still on 43 to 44mph. i went back and done another compression check and this time i got different numbers than before. All the spark plugs look good like brown paper bag. Again i dont know if my gauge is correct but this time the numbers was not in range of each other. This was on cold engine with good battery.

Drivers top 105
middle 100
bottom 90

Passenger top 95
middle 90
bottom 85

Is there anything i can check that would cause this much difference in compression or is rebuild a must?

Also i bought one of the easy timers from 316jughead and checked the timing and it was correct

[swvabassangler]

So i pulled head on the passenger side. The pistons looked good and cylinder walls looked good. I did notice there was gasket maker in the almost all the two small holes that are close together. i have attached pics.

20200817_192209.jpg20200817_192043.jpg20200817_192023.jpg20200817_192016.jpg

[ChampioNman]

Not gasket maker Silicone. That's how you seal the water passages as the motor uses O rings to seal the cylinder and not head gaskets.

[swvabassangler]

Not gasket maker Silicone. That's how you seal the water passages as the motor uses O rings to seal the cylinder and not head gaskets.

Thank that makes sense. Is those compression numbers mean it needs rebuild?

[ChampioNman]

Naw, both backs are good per bank and over all, a good dousing with BRP engine tuner should fix that right up.