rebuilt 1987 50hp johnson wont run,Help

[fpctim]

rebuilt 1987 50hp johnson wont run,Help

i put new rings ,pistons and barings in my motor ,i went through it with a fine tooth comb and found nothing wrong in the motor compressen is good i think top reading is 110 and the bottom is 105 i tourqed everthing to the repair book specs,the reason for the pistons and other stuff is do to poor compression in top cyclinder ,the top was bored when i try to start motor i get popping from carbs and exshust, i also rebuilt carbs and sinked them , the motor wont start at all ,what do i need to do ,im getting fuel ,fire

 

[cammydog]

Re: rebuilt 1987 50hp johnson wont run,Help

Re: rebuilt 1987 50hp johnson wont run,Help

You could be out of time. Check your timing per your repair book.

 

[RPJS]

Re: rebuilt 1987 50hp johnson wont run,Help

Re: rebuilt 1987 50hp johnson wont run,Help

Hi<br />A simple sugestion,have you got the plug leads hooked up correctly

 

[fpctim]

Re: rebuilt 1987 50hp johnson wont run,Help

Re: rebuilt 1987 50hp johnson wont run,Help

yes the plug leads are correct,question if the timing is off the motor will not start?

 

[Dhadley]

Re: rebuilt 1987 50hp johnson wont run,Help

Re: rebuilt 1987 50hp johnson wont run,Help

RPJS is probably on the right path. If the flywheel key is OK check the firing order. I know you say the plug wires are correct but what about the primary leads to the coils? Look at what colors they are and get back to us.<br /><br />Good luck!

 

[bonitoman]

Re: rebuilt 1987 50hp johnson wont run,Help

Re: rebuilt 1987 50hp johnson wont run,Help

coil wires.GREEN on the Bottom. Blue on Top. Green is down on the ground-grass. Blue is up on top to the Sky

 

[rickdb1boat]

Re: rebuilt 1987 50hp johnson wont run,Help

Re: rebuilt 1987 50hp johnson wont run,Help

Tim, check to be sure the timing plate is moving freely and have timing adjusted.

 

[fpctim]

Re: rebuilt 1987 50hp johnson wont run,Help

Re: rebuilt 1987 50hp johnson wont run,Help

thanks rick im taking it in to the shop in the morning all wireing is good i did it one by one by the book

 

[fpctim]

Re: rebuilt 1987 50hp johnson wont run,Help

Re: rebuilt 1987 50hp johnson wont run,Help

also the timing plate moves freely

 

[FletchersMarine]

Re: rebuilt 1987 50hp johnson wont run,Help

Re: rebuilt 1987 50hp johnson wont run,Help

im having a similar problem... rebuild 50 will start, then runs out of gas, fuel is there, carbs full when it dies, seem like the engine is not pulling the gas, can choke it to run, but wont stay running without choking it, rebuilt carbs but still no luck, replaced reeds, still the same, any ideas?

 

[fpctim]

Re: rebuilt 1987 50hp johnson wont run,Help

Re: rebuilt 1987 50hp johnson wont run,Help

WELL IM an auto tech and if a car was doing that then you are sucky air or running to lean you might want to check the fuel diafram if you have one, somtimes they get a pin hole in them and do what your talking about

 

[FletchersMarine]

Re: rebuilt 1987 50hp johnson wont run,Help

Re: rebuilt 1987 50hp johnson wont run,Help

its not the fuel pump (@#$!!) i broke it checking it out Im at the end of my rope with this one, gonna replace both carbs and try it again

 

[ICEMAN]

Re: rebuilt 1987 50hp johnson wont run,Help

Re: rebuilt 1987 50hp johnson wont run,Help

Please don't take this the wrong way, but I had a guy rebuild his motor with the same style pistons. (loop charged flat top pistons)Is it possible they are in upside down? The guy put them in upside down and couldn't get his motor started. compression was good, spark was good, fuel was good. It drove me crazy for about four days, before I found the problem He install the pistons upside down. Just a possibility

 

[FletchersMarine]

Re: rebuilt 1987 50hp johnson wont run,Help

Re: rebuilt 1987 50hp johnson wont run,Help

now how could I take that the wrong way?<br />Im sure there in right BUT a good mechanic will listen more than talk, so, just for fun, Im gonna pull the head to see...<br /> Thanks Iceman

 

[jee70611]

Re: rebuilt 1987 50hp johnson wont run,Help

Re: rebuilt 1987 50hp johnson wont run,Help

Did you replace the top and bottom crankshaft seals? If not, check them out. Two stokes require a good seal to keep their rythmic pressure changes correct. If the seals are leaking then there may not be enough vacuum in the engine to pull enough fuel in without choking it. GOOD LUCK! <br /><br />James<br /><br />PS: Any leak can cause this. Whether it be a bad sealing gasket or seal.

 

[FletchersMarine]

Re: rebuilt 1987 50hp johnson wont run,Help

Re: rebuilt 1987 50hp johnson wont run,Help

Thats exactly what im thinking, not enough vacuum, checked everything but those seals, thanks

 

[Walker]

Re: rebuilt 1987 50hp johnson wont run,Help

Re: rebuilt 1987 50hp johnson wont run,Help

Squirt some pre-mix into the carb throats while you crank it. It should start up even if you have a crankcase leak. That will at least tell you whether you have an electrical problem or not.