1994 Force 120 hp won't start

[Fish Hard]

Hey guys I have a problem with my motor that has me stuck. The engine turns over fine the primer bulb is getting firm the carburator bowls are getting gas in them and the choke is working. Checked all four plugs and the are firing. Still engine will not start. The engine was just running fine a week ago and I ran it about 30 miles and had no problems. Pulled my boat out of the water and ran some fresh water through it due to it sitting in the water for 3 weeks. It ran fine then. When I went to fish the next day it just turns over and will not start. Cleaned plugs and still not starting. After trying to start there is small amounts of gas on the plugs so I think I am getting enough gas to the engine. The only thing I can think of is not enough spark. When I ground the plug to the block and turn the motor over there is a very thin blue line of fire dancing around the center of the plug is this enough fire. The plugs I am currently using are NGK WUHM. thanks in advance.

 

[JB]

Re: 1994 Force 120 hp won't start

Howdy, FH.<br /><br />Check this out: http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=36;t=000001 <br /><br />Good luck.

 

[chad0518]

Re: 1994 Force 120 hp won't start

Originally posted by Fish Hard:<br /> Hey guys I have a problem with my motor that has me stuck. The engine turns over fine the primer bulb is getting firm the carburator bowls are getting gas in them and the choke is working. Checked all four plugs and the are firing. Still engine will not start. The engine was just running fine a week ago and I ran it about 30 miles and had no problems. Pulled my boat out of the water and ran some fresh water through it due to it sitting in the water for 3 weeks. It ran fine then. When I went to fish the next day it just turns over and will not start. Cleaned plugs and still not starting. After trying to start there is small amounts of gas on the plugs so I think I am getting enough gas to the engine. The only thing I can think of is not enough spark. When I ground the plug to the block and turn the motor over there is a very thin blue line of fire dancing around the center of the plug is this enough fire. The plugs I am currently using are NGK WUHM. thanks in advance.

 

[chad0518]

Re: 1994 Force 120 hp won't start

Hey Fish Hard,<br />I know this sounds crazy, but is the "Kill Cord" still connected up by your ingnition? I've spent some time trying to start my own motor when this becomes disconnected!

 

[Fish Hard]

Re: 1994 Force 120 hp won't start

Yes everything seems to be connected. I put some new plugs in today and am getting plenty of fire but still not starting.

 

[Fish Hard]

Re: 1994 Force 120 hp won't start

thanks red sky, will try the fuel mix tomorrow.

 

[eurolarva]

Re: 1994 Force 120 hp won't start

Try pulling out the plugs and leave them out for a few days to air out the system. When you try and start it try spraying some gas oil mix into the carb without priming the bulb and see if it will at least try and start. Maybe you flooded it

 

[Fish Hard]

Re: 1994 Force 120 hp won't start

Tried the oil mix and did not even get a fire. I am going to remove the fly wheel and check out the key in the morning

 

[Fish Hard]

Re: 1994 Force 120 hp won't start

Does any one know the proper torque on the fly wheel nut for an 1994 force 120hp?

 

[funpilot]

Re: 1994 Force 120 hp won't start

My Clymer manual for my Sport Jet 120 (same powerhead I believe as your Force) says 90 ft-lbs.<br /><br />Good luck

 

[duck-n-pond]

Re: 1994 Force 120 hp won't start

Without removing the flywheel to check the key, I think you can do this by pulling the plugs, and moving the #1 cyl to TDC, and your timing indicator should be on 0 degrees. If it's not, then pull the wheel. If it's on 0 degrees, I doubt that thats the problem. Somebody may want to correct me on this procedure.....<br />I have the same problem with my peice of s$%^, and after trying everything, I am suspecting the ignition switchbox may be fried. Apparently this can happen easily. Both cylinders have spark, but no go. I had a cheap spark inline tester, and tried it on my snowblower and worked, but cannot get it to light up on that damn motor!!!!

 

[fixin]

Re: 1994 Force 120 hp won't start

Seloc man says--Flywheel-seial#093699 and later 125ft.lbs.up to serial#OE093699 90ft.lbs, for 70,75,90,120hp

 

[duck-n-pond]

Re: 1994 Force 120 hp won't start

Hey Fish Hard,<br />If you figure out your problem, can you post it here? Your solution may give me some direction to go in, though the engines may be somewhat different. Thanks.

 

[Fish Hard]

Re: 1994 Force 120 hp won't start

Still working on it. I ran into another problem, somehow I burned up my ignition switch. I noticed some corosion on the wiring and I guess it got to hot with all the attempts at starting the motor.

 

[duck-n-pond]

Re: 1994 Force 120 hp won't start

Bummer...I have a line on an oscilloscope today to look at the stator and timing coils, and to look at the output of the ignition box. For those who don't know, oscilloscope is for looking at wave patterns, since I don't have a peak to peak meter...it may not work either, because I doubt that I will get enough sync to see whats happening but you never know. Wish I had a timing light.<br />Question: If on muffs, do you see any sign of smoke exaust from the prop or do you see unburnt gas floating in the water? I see some smoke exaust from mine, so I figure it's close to starting....I hope!

 

[eurolarva]

Re: 1994 Force 120 hp won't start

Hey Duck n pond. I dont think the scope thing will work. At an idle speed of 700rpm the frequency would be 11 hz and at wot at 5500 rpm the frequency would be 91 hz. I dont think a scope will go as slow as 11 hz.<br /><br />IF you are looking for peak to peak voltage you can do this with any AC volt meter. Volt meters read what is called RMS which is about 70 percent of peak value. If you take the AC voltage reading and multiply it by 1.414 you will have the peak to peak voltage. Say you read 10 volts ac then your peak to peak voltage is 14.14 volts.

 

[duck-n-pond]

Re: 1994 Force 120 hp won't start

Nope, I have tried two digital rms and one analog rms meter, expecting to do the same math, but , as a technician and to my suprise, they do not show anything, perhaps because of the pulse rate you mentioned above. I have two fluke digitals, with min/max memories hoping to save the max sample but no way. On a scope, I am hoping to see the amplitude of what I expect to look like noise more so than a nice wave pattern but I suspect you may be right.

 

[eurolarva]

Re: 1994 Force 120 hp won't start

Sorry fish hard. Didnt mean to hijack your thread. I will add this and leave<br /><br />If the scope has digital storage you should be able to set it so it will test a sweep for 10 seconds. The time frame on an idle motor will be 85 milli seconds. If the scope goes as slow as 10 milliseconds per division it will take the whole screen to show one wavelength..

 

[Fish Hard]

Re: 1994 Force 120 hp won't start

No problem eurolarva???? thats what this sight is all about. Duck n pond yes there is a slight sighn of smoke coming from the exhaust. Before the igniction switch burned up it actually tried to run for a few seconds. I am suspecting I have trash in the carbs or lines somewhere but did not totaly break them down. Afraid to I guess. Besides everytime I get a chance to work on it My five year old son is right there with me. Definetly don't want to discourage him from learning.

 

[eurolarva]

Re: 1994 Force 120 hp won't start

If you do the carbs do them one at a time. The carbs are pretty easy. Only a couple of parts to replace. I recommend rebuild kits 18-7037. Napa sells them for 15 bucks a kit. The fuel pump kit is 18-7806 and cost 9 bucks. Try and get into as many small openings as you can with carb cleaner and thin wire then blow them out with compressed air under30 psi. Only use the spray type carb cleaner. These carbs are not suppose to be submerged in old fashioned carb cleaner. It will take the finish off them and ruin the carb. The spray type is pretty weak and works good. Make sure you take all the rubber off before you use the carb cleaner. If you do the fuel pump start with only the diaphram and the gasket. Dont mess with the fuel valves unless you intend on replacing them. Do not use any liquid gasket. Just use the provided gaskets and it should not leak. On the floats. The instructions that come with the rebuild kit is says to adjust float 1/2 inch when it is upside down. I recommend this over the manuals spec of 13/32 inch. You get a better seal on the needle valve.<br />Good Luck