Difficulty planing 77 Johnson 115

[whitejamie99]

Just got the boat back from the shop after an extensive period of repairs - impeller, head gaskets, replaced carbs. I couldn't get the link and sync right so I took it to a local mechanic who fixed a couple of my linkage mistakes and got the boat running correctly. He did not do a WOT timing check though. He also told me that the float was too high on the top carb and that was causing it to "load up" at idle. The symptoms now are rough idle and wont run smooth at low RPMs in gear and when taking off it bogs down and dies. After several tries and playing with the throttle, it will plan and run very well. What do I check now?<br /><br />Jamie White

 

[Goodoleboy]

Re: Difficulty planing 77 Johnson 115

My guess is that you have weak fire on one or more plugs.<br /><br />They have to jump a 7/16 gap. you can buy spark tester at auto parts store. Or you can build your own.<br /><br />Do a search on spark tester here on this forum. Alot of good ones have pictures to go by.<br /><br />Good luck!

 

[whitejamie99]

Re: Difficulty planing 77 Johnson 115

Goodoleboy:<br /><br />Thanks for the reply. Spark tested by me several times and is very strong on all 4 cyl's. Also tested by my mechanic with spark tester just like the ones I've seen on the forum. I have to rule out spark.<br /><br />Also, compression #'s from mechanic were 107, 105, 110 and 108 - a little low but very little variation so I can rule out compression.<br /><br />So that leaves... fuel? timing?<br /><br />Jamie<br /><br />Jamie

 

[Dhadley]

Re: Difficulty planing 77 Johnson 115

All of those symptooms point to carbs and / or sinc-n-link issues.

 

[whitejamie99]

Re: Difficulty planing 77 Johnson 115

Would the float level in the top carb cause this problem? I'm wondering why my mechanic didnt just fix that but thats another subject I will take up with him. Does WOT timing being out cause this problem also?<br /><br />Jamie

 

[Walker]

Re: Difficulty planing 77 Johnson 115

I agree with Dhadley. Who ddi the work for you/ Man you've been fighting with this thing for a long time. If you want to bring it by I'll do the carbs and link &sync for free. You buy the Dr. Peppers

 

[Basscat 1]

Re: Difficulty planing 77 Johnson 115

You cant beat a deal like that, since both of you live in San Antonio.

 

[whitejamie99]

Re: Difficulty planing 77 Johnson 115

Walker: Thanks, thats a great offer. How do I contact you? My email is whitejamei99@hotmail.com. Can you email me off forum and exchange contact info. I'd really like to see first hand how to link & sync.<br /><br />Jamie

 

[Walker]

Re: Difficulty planing 77 Johnson 115

Email sent

 

[whitejamie99]

Re: Difficulty planing 77 Johnson 115

Walker:<br /><br />I misspelled the email. It should be:<br /><br />whitejamie99@hotmail.com<br /><br />You probably will get a message that the other one is undeliverable.<br /><br />Sorry for the mistake<br /><br />Jamie

 

[DPBJR]

Re: Difficulty planing 77 Johnson 115

Jamie PLEASE post what you guys find. I have had this problem for years. My 1977 115hp engine has seen 5-6 authorized Johnson dealers and still dies on take of unless you nurse it.<br /><br /> Dave

 

[whitejamie99]

Re: Difficulty planing 77 Johnson 115

DPBJR:<br /><br />Will do. We are scheduled to do this on Saturday and I will put the boat in the lake on Sunday. Will post how this comes out. Its great to have Walker so close.<br /><br />Jamie

 

[Walker]

Re: Difficulty planing 77 Johnson 115

We're gonna do several things to the motor, so if we fix it it may not be obviuos exactly what the problem was.

 

[Boilermaker]

Re: Difficulty planing 77 Johnson 115

Free help in person>>>><br />Gotta love them Texans!!!

 

[Walker]

Re: Difficulty planing 77 Johnson 115

Well, we gave the carbs a good soaking and that didn't help. Went on to do a link and sync and nothing was as it's supposed to be. I do believe Jamie has some older model linkage on his motor. Could only get the carbs set right on the second line on the throttle cam. He may even have a different flywheel on it. The only reasonable idle we could get was at least 12 BTC. Wouldn't run period anywhere less. Motor sounded and reacted to throttle pretty good when we were finished. Jamie is going to give it a lake test tomorrow, that is, if he isn't in trouble for spending the whole afternoon at my house instead of doing honeydos. He said he would index the flywheel too when he gets a chance.

 

[whitejamie99]

Re: Difficulty planing 77 Johnson 115

No go on the lake outing Sunday. Had to paint the fence. What a bummer. <br /><br />Many thanks to you Walker, I learned a great deal about my motor - nothing like seeing how to do something in person instead of guessing or trying to interpret what a manual means.<br /><br />A friend at work said there shoud be some adjustments on the carbs to control the fuel/air mixture problem that we were encountering early in the day. He has a gauge that measures the mixture and I might try that.<br /><br />I'm assuming that indexing the flywheel relates to adjusting the pointer - finding TDC, etc as we discussed.

 

[Walker]

Re: Difficulty planing 77 Johnson 115

Yep, that's indexing Jamie. You can do all 4 cylinders. Your carbs are non adjustable unless you change the jet sizes

 

[whitejamie99]

Re: Difficulty planing 77 Johnson 115

Great news!!! The boat performed great. Took it out after work on Monday with my son who is learning to back the trailer in the water. Boat started within 5 revolutions on first crank. Idled well with some white smoke at first that went away. After warmup we took off and boat jumped up onto plane with no hesitation. We ran wide open for about 20 minutes and motor didn't heat up or miss. Stopped at my moms boat ramp and we lost the plug. Luckily we had another. Did several stops and starts - shut it down in the middle of the lake and waited 5 minutes and it started right up. Idle is good and trolling at no wake speed is fine. One time it bogged for a second after trolling for 3-5 mintutes but it got up on plane right after.<br /><br />WALKER - I THINK YOU FIXED IT!!!! THANKS SO MUCH.<br /><br />I'm not going to mess with anything - just going to enjoy it on the lake this weekend.<br /><br />Jamie