89 Johnson 150 gt Boggs!

[brandon6.0]

Well running into a few problems. My friend has a 89 Johnson 150 on a bass boat. Said when he first got it he rebuilt the carbs him self and we just changed the plugs and new gas with 50.1 mix 2 stroke oil.

He said it was running good when he first rebuilt the carbs. Well we took it out for a ride and played hell getting it started. Finally she fired up and all we could get it to do is idle along in gear. Any more throttle and it would stumble and die. Hit the key and it would fire right back up like a brand new one. In nuetral you can get it to rev to the max. But in gear all u can do is idle along. What do u guys think? I took all fuel lines off tonight and i had good pressure and fuel coming all the way through the fuel pump and out to carb inlets. Does this mean the fuel pump is good? Spark seems fine on all coils as well. I really think it is a fuel issue. Could the low/high idle screws being off cause this as well?

thanks guys!

 

[MRneatfreak]

Re: 89 Johnson 150 gt Boggs!

Hmm, have you checked compression lately, if ever? Sounds like a classic example of a blown cylinder. It will idle all day, but once you put a load on it, it dies.

 

[brandon6.0]

Re: 89 Johnson 150 gt Boggs!

yeah i have read about doing that. Ill try and check it today, and report back.

 

[brandon6.0]

Re: 89 Johnson 150 gt Boggs!

ok here is an update. Checked compression and i have 100psi on all three cylinders on the starter side. On the other head i got 110psi on all cylinders. That is a pretty good reading correct? I also, took carbs back off and stripped of all gaskets, and plastic. Got them soaking in gunk carb cleaner over night. All the fuel lines seem good i blowed through all of them. I took fuel pump apart and both diaphrams seem great. No cracks in housing or anything.

Only thing i got left is the coils. One is brand new. The rest are old and cracked up pretty good. I also checked over the plugs and noticed that three were really dark like they werent buring the fuel off. The others were really clean and looked brand new pretty much. You think with three coils not firing would cause it to bog this bad? whats the chances of three coils going out around the same time? should i replace all of them?

Thanks guys. Also, I found behind the bottom carb going into the intake on the starter side a plasic hook piece from a clothes hanger. It was just sitting in there luckly it was hung up and didnt get into the cylinder. Could this be an issue? Fuel puddling up.

 

[metriccrescentwrench]

Re: 89 Johnson 150 gt Boggs!

It's curious that 3 plugs look brand new. Is there any evidence of water in the cylinders those plugs came out of? Are you sure there's good spark on all cylinders? (You'll need to get an adjustable gap spark checker, available from any auto parts store - set it to 7/16").

 

[brandon6.0]

Re: 89 Johnson 150 gt Boggs!

yeah i for got to get a spark tester earlier today. I think three of the plugs got fouled out. It did take us about thirty mins to get it started and running at the river. Could have fouled them out thin, before we even test drove it.

 

[emdsapmgr]

Re: 89 Johnson 150 gt Boggs!

Likely that the engine is not running on all 6 cyls. With that engine, it's hard to tell it's missing on one or more cyls when on the trailer. All engines seem to idle well when running out of water-even on 3 or 4 cyls. It's another thing when the exhaust is 24" underwater-and in gear. You need all 6 cyls firing. Possible the 3 shiny plugs are not firing-the unburned fuel and oil is going right out the exhaust. Easy to check for spark with an inductive timing light. Those coils are generally very reliable. Very unlikely that 3 would go out at once. You can swap them for testing purposes. Check the power pack, stator and timer base. You can find ignition troubleshooting information for your engine at cdielectronics.com.

 

[James R]

Re: 89 Johnson 150 gt Boggs!

Were new kits used in the carb rebuild and was attention paid to the float height settings. Will the motor pick up if you squeeze the primer bulb. The motor may fire and rev on no load but you may have a whole bank of cylinders not firing.

 

[brandon6.0]

Re: 89 Johnson 150 gt Boggs!

ok i talked to him and he said that he only took them apart and cleaned them with carb cleaner. Didnt really go into the carbs to deep. So i think they are ok bc i took them apart myself and let them soak for a few hours. Here is what i have come up with. I got a spark tester and set it at 7/16 gap. checked all coils and they were jumping the gap perfectly. Well put the engine back together an hour ago and fired her up and let her idle a lil while and i could tell is was missing or skipping. Checked all the coils agian wiht the tester and noticed that three coils are not firing now. They were earlier and now they aint. Maybe the heat has effected the ignition power pack. I noticed the timing is not moving forward either. I think this is the problem. What you all think?

 

[metriccrescentwrench]

Re: 89 Johnson 150 gt Boggs!

Well, if you're not getting spark on 3 cylinders you've definitely found a problem. Now your job is going to be figuring out which component is at fault without going broke blindly replacing parts.

I looked at the parts diagrams on shop2.evinrude.com and it looks like you have a single power pack, not dual packs like some earlier engines. That means that it's less likely the culprit is a power pack, though not impossible.

Check the connectors going to the power pack from the timer base, if one of those were loose you'd loose spark on 3 cylinders.

Does that engine have a shift assist switch? What that does is kill the spark to one bank of cylinders as you shift out of gear, sometimes those get out of adjustment and cause problems. If this engine has that you can just disconnect it for testing purposes.

Next I'd suggest swapping the coils, take the ones from the cylinders that didn't fire and swap them with the cylinders that didn't show a problem. See if the problem follows the coils or stays put.

 

[brandon6.0]

Re: 89 Johnson 150 gt Boggs!

what about the rectifier? Heard it could cause synptoms like this. I can check it by disconnecting two yellow wire and see if engine clears up at idle. But i dont have a clue were this thing is located at. Any help on this?

 

[emdsapmgr]

Re: 89 Johnson 150 gt Boggs!

The rectifier is part of the engine's charging system. Separate from the ingition system on that engine. The miss is on the ignition side.

 

[brandon6.0]

Re: 89 Johnson 150 gt Boggs!

ok i we will order a power pack this week. Will report back with results.

 

[MRneatfreak]

Re: 89 Johnson 150 gt Boggs!

I find it hard to believe that all three coils on one bank have no spark due to a power pack. I think the power pack is a waste of money at least for the moment. Are you sure you had a good ground on your spark tester. It makes sense that you had a good ground for one back of the engine and you got a good spark, but when you moved the spark tester for the other bank and chose another grounding point it didn't have a good connection. There has to be bare metal contact on the engine block, nothing painted. If in doubt use a multi-meter between the negative starter bolt and whatever bolt head you were using for the spark tester, set it to 200 ohms or less and you should read less than 5 ohms. If not then choose another grounding point.

 

[clanton]

Re: 89 Johnson 150 gt Boggs!

Check the shift switch. Switch may be sticking, will kill 3 cylinders. Cracked coils should be replaced.

 

[brandon6.0]

Re: 89 Johnson 150 gt Boggs!

ill check the shift switch didnt think about that.

Here is how the spark was From looking directly from behind engine on each cylinder

(top) sparking (top) spark
(middle) no spark (middle) no spark
(bottom)-Brand new coil pack /no spark (bottom) spark

Now before i ran engine it had spark to all cylinders. this was after running engine for maybe ten mins. The ground for spark tester checked on all cylinders was left in the same spot.

 

[emdsapmgr]

Re: 89 Johnson 150 gt Boggs!

Weak ignition components tend to fail once the engine heats up to normal operating temps. Checking the spark when the engine is cold may give you the same results after the engine warms up...

 

[brandon6.0]

Re: 89 Johnson 150 gt Boggs!

yeah from what i have read and researched they said the rectifier/regulator and ignition components tend to show there true colors when the engine is warmed up to operating temps. Now i checked the rectifier from the battery and had 12volts and started engine and it showed 12volts still. Does that mean that it is working? Now i noticed the fuel pump is leaking when u prime the fuel full via the bubble. It leaks right where fuel exits to the carbs. There is a small round plastic piece right next to the exit. When i took pump apart diaphrams looked good. I saw where there was a small passage with a small hole that went to this piece that is leaking. Might of had something to do with the oil injection. Not sure. But with engine running u can tell it is missing like its not running on all cylinders. Fuel wouldnt make it sound like that. Three plugs where foulded out also. So its got to be the power pack. I told my buddy about it and he is trying to scrap up the money to order one.

 

[brandon6.0]

Re: 89 Johnson 150 gt Boggs!

ok here is where we are at today. Messed with it a lil more. Checked spark and the brand new coil is not sparking as strong as the others. But still i dont think this would make it run the way it was running. we also, noticed that the module under the flywheel that i geuss is supposed to advance timing toward the bump stop, does not move at all. You think this is got the timing all out of wack! With it running you can tell it has a skip to it. But without the timing advancing wouldnt this make it bogg like crazy out the hole and stall out? I would think so.

 

[emdsapmgr]

Re: 89 Johnson 150 gt Boggs!

Right on! The timer base (under the flywheel) must move with the spark advance lever in order for the engine to make hp. You need to make sure the link arm with the ball and socket is connected between the timer base and the top of the spark advance lever.