77 Johnson 115 dead spot

I have a 1977 115 hp 2 stroke Johnson Outboard. It has sat dormant for more than six years; that is until yesterday. After a long wait, I replaced 3 ignition coils, rectifier, spark plugs, new fuel in carbs and tank. We took it out on the water yesterday for a test run. It did run, but every time we tried to throttle up to a high rpm, the engine would die. If I removed the cover, and manually advance the throttle quickly past the dead spot in nuetral, it would rev up no problem, but trying to use the control unit to increase rpm's in gear would not work. So I dissassembled both carbs yesterday, carefully removing and inspecting all orifaces, but there was no noticable obstructions. ?? Can anyone tell me what would cause a dead spot while trying to incease rpm's???
Thanks for any help!

Re: 77 Johnson 115 dead spot

bad wire on the timer base could be suspect.

pull the plugs one by one while having a helper turn key, and see if its sparking on all cylinders.

one way to do this is to put the thread of the spark plug onto the block to ground it, or get a spark tester. I think you know this already as you can rubuild the carbs no problem, you probably know that trick.

do you have a multimeter? you can probe the timer base connectors to check for 30-60 ohms.

that plug is a 4 wire plug, that plugs into each power pack. your checking the A & B and A & C plugs

I can take pics of the plugs you need to test if you want.

Re: 77 Johnson 115 dead spot

Thanks for the help BigB9000! I will try that tomorrow after work. I have Seloc to referr to if need be for the wiring on the timer base connections.
Thanks again!
Jason

Re: 77 Johnson 115 dead spot

you did not replace on of the most important parts, impeller, that motor needs a water pump kit. before you toast the block, and waste the money, on all those other new parts. a linc n sinc, may help your problem, did you use rebuild kits on your carbs? did you do all this? http://forums.iboats.com/showthread.php?t=244013

Re: 77 Johnson 115 dead spot

The water pump was replaced before I stored the boat six years ago. So it is unused until now. Also, six years ago I rebuilt the carbs w/ rebuild kits. A linc n sinc?? Never heard of it. I will check out the link you sent. Thanks
Jason

Re: 77 Johnson 115 dead spot

That water pump is toast after sitting for 6-years dry. Replace it.

Also, your problem is most likely in your carbs. You won't see the blockage by visual inspection, but it's there. I can almost guarantee that after six years of sitting there's varnished fuel sitting in your main jets or the passage behind it. Get a couple of kits, soak the carbs overnight and rebuild them properly.