1979 Johnson 150 "kick"

[Thompy_04]

Just purchased an 89' Glasstream Bass Boat with a 150 Johnson, 79' model. Compression is good 120,115,115,115, 115, 120, spark is good also will jump 1/2" or better. It will idle fairly well, every 5 seconds or so though, it will kick like its missing. New plugs same thing, I have the carb kits and a manual on the way, as I worked on an old '60 model 18hp and that helped but this is a different beast. Am I going in the right direction, and if the carb kits don't fix the problem what should be my next best move?

 

[steve6]

Re: 1979 Johnson 150 "kick"

check the caps and wires, sometimes there is damage to them from the cover and they jump/short out or they just get old. A simple test is take a insulated handle screw driver with the tip near the block and run it close/along the wires. It will miss/spark across the screw driver if there is an issue(the motor will 'kick' as you described below). This is while running of course.

*** be careful you could get shocked yourself if not careful and it HURTS ***

also, does it still do this after warmed up? the older two strokes are sometimes rough until they warm up.

 

[emdsapmgr]

Re: 1979 Johnson 150 "kick"

It is possible you are describing a "lean sneeze." This is best described as an intermittent miss in the engine at idle only. This is actually a carb problem, not an ignition problem. When one or more of the idle passages get restricted over time with debris or old/dried fuel, the engine can run lean at idle. This lean condition can cause the engine to miss every few rpm. Solution is to overhaul the carbs, specifically paying attention to cleaning out the idle passageways in the upper carb bodies. An aerosol carb cleaner sprayed though all the carb passageways should resolve the problem. You have very good compression for that year engine.

 

[Thompy_04]

Re: 1979 Johnson 150 "kick"

It is possible you are describing a "lean sneeze." This is best described as an intermittent miss in the engine at idle only. This is actually a carb problem, not an ignition problem. When one or more of the idle passages get restricted over time with debris or old/dried fuel, the engine can run lean at idle. This lean condition can cause the engine to miss every few rpm. Solution is to overhaul the carbs, specifically paying attention to cleaning out the idle passageways in the upper carb bodies. An aerosol carb cleaner sprayed though all the carb passageways should resolve the problem. You have very good compression for that year engine.

I will get back with you guys when I get the kits installed. It wasn't hard on that old 18 but it only had one carb of course. We'll see, I'll keep you guys up to date.

 

[Thompy_04]

Re: 1979 Johnson 150 "kick"

Got the carbs clean and in, just have a few quick syncing questions. Manual says for throttle pickup roller to be under the first "small" scribe mark, mines more between the first scribe and the "start" scribe. No matter what I do with the adjustment it won't move back that far. However in neutral with the cold start up it is inline with the "start" scribe, take it off, back to just about halfway between the two. Correct procedure?

Secondly is the throttle pickup roller suppose to have rubber around the plastic, my 18 did, but this lacks rubber just clear plastic. Need replaced to have a correct link?

Note: Butterflies open up horizontal at WOT and fully closed at idle. Is it necessary to create the "exaduration" tool to see when the butterflies start to move.

 

[emdsapmgr]

Re: 1979 Johnson 150 "kick"

Most throttle rollers do have a thin, clear plastic cylinder layer as the outer part of the roller. Over time, these tend to deteriorate and when these plastic cylinders layers break away, they reduce the diameter of the remaining roller. Unfortunately, this will affect the relationship between the timing and the carb throttle plate opening. In other words, it may not run quite right. It is a cheap replacement. Make sure this roller is in good condition before you do the sync and link. I'd probably disconnect the throttle cable when trying to initialize the idle setting. You should be able to adjust the throttle cam by screwing in/out the throttle cam yoke. Reconnect the throttle cable (in may require some minor ajustment) when you get ready to set the cam when using the cold start lever. Are you working from an original factory service manual?

 

[Thompy_04]

Re: 1979 Johnson 150 "kick"

Unfortuneatly no, not working out of a OEM manual. I have ordered one for peace of mind though. Do you guys have any idea what part number the throttle pickup roller is? I've got the sync part down now, just need that roller to complete.

Note: Throttle and shift cables are disconnected while this process is completed.

 

[emdsapmgr]

Re: 1979 Johnson 150 "kick"

308199 is the original 1979 cam roller number. Around $3.50 from any Bombardier dealer. All of these parts are online. You can look them up from Bombardier's website. Complete with illustrations. Pretty cool! website is: epc.brp.com

 

[Thompy_04]

Re: 1979 Johnson 150 "kick"

Got the roller, sync'd the carbs but still has a miss at idle. Thought it might be bad spark from the #2 hole as the spark was a little weak and the coil was leaking its potting. Replaced the coil still no change. Starts right up, but has a terriable miss every 10 seconds or still though. Any suggestions? Timing, still an incorrect sync and link?

 

[jonesg]

Re: 1979 Johnson 150 "kick"

Try one of these, if its electrical it should be evident.

Establish the spark gap using a large steel fender washer.
Watch the video, it become obvious.

http://s691.photobucket.com/albums/vv276/snapc33/boat/?action=view&current=MVI_1450.mp4

 

[Thompy_04]

Re: 1979 Johnson 150 "kick"

Got frusterated today and decided to start from scratch. Got my 6 gallon tank of fresh fuel from my 18hp, linked and sync'd carbs again, and changed the primer bulb and line. Again I checked and verified spark to all cylinders which checked out good. Low and behold it will idle all day on muffs now, no even a spit. I must not have cleaned that tank good enough is all I can think of, but when I can water test this weekend I'll keep you guys up to date.

 

[Thompy_04]

Re: 1979 Johnson 150 "kick"

Hey Jonesg just curious because its such a cool little tool, what is that spark tester made of? Looks like a automobile distributor cap? Just like to make one to have around for the future.

 

[jonesg]

Re: 1979 Johnson 150 "kick"

Yeh an old distributor cap, one of the forum members posted it a while back, real neat trick.
His neighbors car won't start though.

 

[dazk14]

Re: 1979 Johnson 150 "kick"

Could you snap a couple of pics of the center lug and washer connection?

GREAT looking tool!!

 

[Thompy_04]

Re: 1979 Johnson 150 "kick"

Water tested today, same deal. Fires up, runs in idle, but still misses. Can't even shift into gear. Should be an electrical issue IMO but I still have spark. I have to have a cylinder missin' somewhere. I've got all winter to figure this out, but I'm gettin' furious!

 

[Thompy_04]

Re: 1979 Johnson 150 "kick"

Top of my head guys, fuel pump? My primer ball is going soft, pump it idles better. Can this pump be rebuilt or is two new ones needed. Screens on both are clean, no damage seen on either pump

 

[Thompy_04]

Re: 1979 Johnson 150 "kick"

Just got back playin' with this again this afternoon, and got this as well. I was confiming spark while running one plug by one and all of the plugs could be checked except the bottom 2 on the port side. What I mean by this is that I could plug the other 4 plugs into a spark gap tester and start and run the engine, with either the bottom 2 on the port side unplugged it wouldn't start. Just throwin' it out there, looking for any kinda info.

 

[oxbeast1210]

Re: 1979 Johnson 150 "kick"

WHen you water tested it did you use your 6 gallon tank or the one on the boat?
if the problem went away when you had it on the 18hp's tank seems like that would have narrowed down the issue some maybe a leak in your fuel lines ?
if you used the 6 gallon tank when water testing then we are back at square one lol

 

[Thompy_04]

Re: 1979 Johnson 150 "kick"

Yeah used the portable tank, same thing. I can't rule out carbs just because I rebuilt them, but I believe in all honesty I've got an electrical issue. Also plug wires, do they pull out of the coils or does the whole assemble need to be replaced?

 

[oxbeast1210]

Re: 1979 Johnson 150 "kick"

what rpms do you have it idling at? is it possible that it may be set to low?