# Johnson 28 SPL no spark



## Aaronjeep2 (Nov 18, 2016)

ajkulish said:


> You guys are gonna love this.
> 
> Turns out the carb was not the culprit at all. The thing sucked up a part of a plastic bag at some point :lol:
> 
> Of course I couldn't see until I took the carb off, but I'm glad I did. It was keeping the reed valve from ever fully sealing and just made the thing limp along haha. Oh well, carb rebuild kit is on the way, and this thing should be ready to rock by the end of the weekend. Good thing it was a relatively easy fix.


LOl wtf


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## ajkulish (Nov 16, 2013)

Aaronjeep2 said:


> LOl wtf


I guess thatll happen with no intake filter. Does your motor have one? I have been looking up and down and can not find a single image of a motor that has one. There is a bolt pattern there for it, but i cant find anything about it. 

In the carb rebuild kit though, there is one strange looking gasket that looks like it would bolt up to that pattern, is that supposed to be the intake screen? Im referring to the gasket on the bottom left


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## Aaronjeep2 (Nov 18, 2016)

ajkulish said:


> I guess thatll happen with no intake filter. Does your motor have one? I have been looking up and down and can not find a single image of a motor that has one. There is a bolt pattern there for it, but i cant find anything about it.
> 
> In the carb rebuild kit though, there is one strange looking gasket that looks like it would bolt up to that pattern, is that supposed to be the intake screen? Im referring to the gasket on the bottom left


No carb/intake filter on mine


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## piketroller (Oct 24, 2016)

ajkulish said:


> You guys are gonna love this.
> 
> Turns out the carb was not the culprit at all. The thing sucked up a part of a plastic bag at some point :lol:
> 
> Of course I couldn't see until I took the carb off, but I'm glad I did. It was keeping the reed valve from ever fully sealing and just made the thing limp along haha. Oh well, carb rebuild kit is on the way, and this thing should be ready to rock by the end of the weekend. Good thing it was a relatively easy fix.


Did you see signs of any other debris at all in there. Mice like to pull all sorts of trash into tight places to build a warm nest in the winter.


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## ajkulish (Nov 16, 2013)

piketroller said:


> Did you see signs of any other debris at all in there. Mice like to pull all sorts of trash into tight places to build a warm nest in the winter.


This was a thought of mine as well, but i did not find anything else in there. I took the leaf plate off and inspected, but found nothing else. I also rebuilt the carb yesterday and am looking forward to slightly warmer weather to try to fire it. Dont even want to be outside right now.


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## ajkulish (Nov 16, 2013)

Well, fired it today and it ran on only one cylinder despite having compression and spark in both. Wondering if some of that bag clogged the intake port or something. Ugh. 

Sent from my SM-G930V using Michigan Sportsman mobile app


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## piketroller (Oct 24, 2016)

ajkulish said:


> Well, fired it today and it ran on only one cylinder despite having compression and spark in both. Wondering if some of that bag clogged the intake port or something. Ugh.
> 
> Sent from my SM-G930V using Michigan Sportsman mobile app


Try swapping the plug wires to make sure it’s a cylinder issue. When the coils start to go bad, they can be intermittent enough to make troubleshooting quite difficult.

Also, is the plug in the non firing cylinder wet, indicating that it is getting fuel?


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## ajkulish (Nov 16, 2013)

Thatll have to wait a minute. I broke a plug wire terminal on the coil pack when taking the cylinder head off after it not running, wanted to inspect further. So i have to get coil packs anyway! haha. 

The plug was somewhat wet, not soaking. I dont know why one would get fuel and the other wouldnt though, unless the intake port is clogged. 

When i pulled the plug wire on the bottom cylinder the engine would still somewhat fire on the top cylinder. Not vice versa.


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## hawgeye (Mar 3, 2011)

piketroller said:


> Glad you figured it out. Now you need to add "run the gas out" to things to do at the end of the season, and good practice for any carb-ed marine engine if it's going to sit for more than a week. And at the end of the season, drain all the fuel out of the primer bulb assembly as well, by either removing the end fittings and draining, or just unplugging from the tank and run the gas out when you are doing it with the motor.


Or just run rec gas and never worry about doing all those extra steps!

Sent from my XT1710-02 using Michigan Sportsman mobile app


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## ajkulish (Nov 16, 2013)

Well, I believe my problem still lies in the leaf plate/reed valve. As the head was off, I would rotate the motor and as piston 1 went forward you could hear a fairly loud "whoosh". As piston 2 went forward, no noise. Looking at the leaf plate while doing this, you could see that the leafs would both open, but piston 1 was not perfectly sealed while resting. While piston 1 returned (moved down) in segmented strokes, you could see the reed valve push back against the plate. This was not the case for piston 2. So i did my best to track down a good leaf plate, but they are all used. Hopefully the one I chose is good. Also got new leaf plate gasket, and head gasket. Coil pack is on the way as well. 

Fingers crossed.


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## Aaronjeep2 (Nov 18, 2016)

ajkulish said:


> Well, I believe my problem still lies in the leaf plate/reed valve. As the head was off, I would rotate the motor and as piston 1 went forward you could hear a fairly loud "whoosh". As piston 2 went forward, no noise. Looking at the leaf plate while doing this, you could see that the leafs would both open, but piston 1 was not perfectly sealed while resting. While piston 1 returned (moved down) in segmented strokes, you could see the reed valve push back against the plate. This was not the case for piston 2. So i did my best to track down a good leaf plate, but they are all used. Hopefully the one I chose is good. Also got new leaf plate gasket, and head gasket. Coil pack is on the way as well.
> 
> Fingers crossed.


Did you put the reed valve on upsidedown ?


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## ajkulish (Nov 16, 2013)

This thing is giving me so many problems. 

I readjusted the carb as it was misadjusted, i also got a new leaf plate and gasket on, and i put on a new headgasket and reassembled. Well, unfortunately something i didnt notice was that the bottom cylinder spark plug threads were cross threaded at some point, keeping it from building compression in that cylinder. So i got a helicoil kit, and put it in, but air pisses right past it. So i lathered it up with red RTV and i can feel it build some compression as i turn it over, but not as much as the top cylinder. I dont know if the rings got ****ed up at some point or if there is still air leaking past the helicoil. 

I am getting very frustrated with this. I had it running when i teflon taped the threads but it would only want to idle on one cylinder, but if i could start it and get back to the motor in time and apply a little throttle, i could keep it alive for a moment or two, running on both cylinders, but then would "POP!" and the motor would shut off. Not sure if it was backfire or afterfire. I dont know if the timing is off, or what the deal is.


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## Aaronjeep2 (Nov 18, 2016)

ajkulish said:


> This thing is giving me so many problems.
> 
> I readjusted the carb as it was misadjusted, i also got a new leaf plate and gasket on, and i put on a new headgasket and reassembled. Well, unfortunately something i didnt notice was that the bottom cylinder spark plug threads were cross threaded at some point, keeping it from building compression in that cylinder. So i got a helicoil kit, and put it in, but air pisses right past it. So i lathered it up with red RTV and i can feel it build some compression as i turn it over, but not as much as the top cylinder. I dont know if the rings got ****ed up at some point or if there is still air leaking past the helicoil.
> 
> I am getting very frustrated with this. I had it running when i teflon taped the threads but it would only want to idle on one cylinder, but if i could start it and get back to the motor in time and apply a little throttle, i could keep it alive for a moment or two, running on both cylinders, but then would "POP!" and the motor would shut off. Not sure if it was backfire or afterfire. I dont know if the timing is off, or what the deal is.


The back fire could be from sucking air into the cylinder via the spark plug hole. Maybe you could drill out both cylinders and tap them and put a little bigger spark plugs in it. Remember this once you get it running good you replaced a lot of parts so you won't have to worry about it breaking at 5am on opening day of duck season.


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## ajkulish (Nov 16, 2013)

Yeah i guess you're right. ordered another head gasket, a new head, and some plug wires as they were iffy. Will give her another shot next week.


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## Aaronjeep2 (Nov 18, 2016)

ajkulish said:


> Yeah i guess you're right. ordered another head gasket, a new head, and some plug wires as they were iffy. Will give her another shot next week.


You can inspect the rings and piston if you remove the water cooler plate thing. Be careful I broke 4 bolts on it so rtv was my friend. Don't try to drill steel bolts out of aluminum when drunk lol. Don't mind my ghetto fuse ether. Took the boat out yesterday hit 25 mph with a busted up prop fishing gear and the girlfriend not to
Shabby for a 1642 mod-v.


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## ajkulish (Nov 16, 2013)

Haha, i get that. I had snapchat telling me 28mph on this boat when it was my buddies. I also had put a compression tester to the motor and had 90 psi in one cylinder, and 70 in the other (even though the compress tester was not seated fully, as the bottom piston would hit the tester for some reason). The cylinder walls were not bad looking at all, the pistons rocked some but thats to be expected when cold and unlubricated. I also removed the intake plate on the other side and saw the rings, they didnt look too shabby. My head arrived saturday, and the gasket will be here today so we will know more by tomorrow. Wish me luck.


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## Aaronjeep2 (Nov 18, 2016)

ajkulish said:


> Haha, i get that. I had snapchat telling me 28mph on this boat when it was my buddies. I also had put a compression tester to the motor and had 90 psi in one cylinder, and 70 in the other (even though the compress tester was not seated fully, as the bottom piston would hit the tester for some reason). The cylinder walls were not bad looking at all, the pistons rocked some but thats to be expected when cold and unlubricated. I also removed the intake plate on the other side and saw the rings, they didnt look too shabby. My head arrived saturday, and the gasket will be here today so we will know more by tomorrow. Wish me luck.


Good luck I hope it runs right with the new head it should since you will have a tight seal around the spark plugs.


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## ajkulish (Nov 16, 2013)

Sigh, this thing is getting annoying. 

Replaced the cylinder head and gasket, with no difference in results. I can get it to fire intermittently, but cant get anything consistent. I zip tied the throttle wide open and started it up once, and the thing ran at full throttle for about 15 seconds before dying. I could not replicate this. I cut the zip tie, and tied a string to it so i could modulate the throttle after id get it to start a little bit, but i still get afterfire. It will run for a second, then POP! and the water splashes. Most definitely not a backfire, but afterfire. This would lead me to believe it is running rich, but i adjusted the carb per the owners manual. Turning the screw in yields no different results. I have 90psi compression in top cylinder, and upon second check, i have 60 in the bottom. From what i read, the motor should run fine with over 60 psi. I know i am cutting it close, so maybe it is the rings. Maybe its that im running pump gas and not rec gas. Dont think 10% ethanol tops would cause it to not run at all though. Also, after trying to start it for a while, and off and on success, the primer bulb will not be full and pressurized. Not sure if this is normal or not. 

Any thoughts?


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## piketroller (Oct 24, 2016)

My thoughts would be to start saving for this:


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## ajkulish (Nov 16, 2013)

Haha im too deep into this m'fer already. And i have accomplished much more with a motor way more complicated than this. I cant let a damn 2 stroke defeat me.

Last summers project that i did.


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## ajkulish (Nov 16, 2013)

Probably wise. I considered this, but i dont think I can fit my 6 gal up front. The hatch has a pretty small opening.


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## piketroller (Oct 24, 2016)

Hatch? We don’t need on stinking hatches.

Just sit it on the front deck and maybe add a strap to keep it in place. If it helps the performance enough after the first sea trial you can figure out it’s a worthwhile change. You can always move it out of the way when you aren’t operating at speed.


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## piketroller (Oct 24, 2016)

Here’s my fuel tank setup. I couldn’t fit the big 12 gallon tank in the back under the splashwell plus the weight is better up front when it’s just me.


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## ajkulish (Nov 16, 2013)

What size battery do you run for that troller?


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