Sport jet 120 help

[kscooby28]

start by saying it is a 95 sugar sand mirage. i bought the boat needing a starter. got the starter and it fired up. took it to the water and after bout 30 min of starting and stalling i manuallly held the throttle till i got it in gear and we were off. rode for about an hour no problems. com back to the dock and it stalls a million times again. get it home clean the carbs, find out that the vent tubes for the carb were clogged, get it back out. awesome. ride for a while then i shut it off to anchor and do some swimming.... doesnt wanna start. 30min...1 hour.... 1 1/2 hour... finally starts again. get home decide not to use untill im ready to figure that out. after letting it sit about a month, now it wont start at all. when i turn it over gas just starts pouring out of the carbs. what is a safe way to check spark, and what was up with it not wanting to start hot!?!?!?! and now not starting at all. PLease help

 

[kend301]

Re: Sport jet 120 help

If you have fuel pouring out of the center jet in the carb the floats aer stuck down either due to
1 a bad float
2 stuck needle for the float
3 still have restriction in the vents

To check spark buy a spark tester at an auto store or pull one plug move it as far away from the plug hole as you can , hook the wire up and ground the threads , crank the engine and look for spark while cranking.

 

[kscooby28]

Re: Sport jet 120 help

i forgot to mention that while cranking, fuel is flowing through and out of the vent line. they are def unrestricted from the bowl chamber

 

[kend301]

Re: Sport jet 120 help

If you have fuel running out of the vents then
1 Floats are out of adjustment
2 Floats are sinking in the gas
3 Stuck needle and seat
4 Bad needle and seat

Pull the carbs and rebuild them with new floats, needles and seats and your problem will be fixed.

 

[kscooby28]

Re: Sport jet 120 help

ok got that done. doesnt seems to flow out anymore. when i went to go start it it had enourmous compression. upon closer inspection i had water in botton 2 cylinders. ( got it all out, is there anything i can spray in there that will help prevent corrosion from the water?) ok now shes spins fine, has about 150psi on all 4 cylinders... but no spark. i checked for voltage at the black and yellow(kill) and there was no voltage. i have the manual for this motor but it kinda sux. where do i start on this. i have the red strator.

 

[kend301]

Re: Sport jet 120 help

OK gotta start somewhere on this one
Water in the motor
1 Did you have a flush kit hooked up to it when you were troubleshooting the carbs?
2 If so was the hose wide open as this will flood the motor
3 If not then you need to put a head gasket and a exhaust manifold gasket on
No Spark
Do the tests in the first thread posted in this section "Sport Jet Info and Basics" post results .

 

[kscooby28]

Re: Sport jet 120 help

yeah i had the flush hooked up but the pressure was low. i think it may be because i have inconsistant water pressure it will surge sometimes even on low pressure. ok im gonna check that forum now thank you very much for helping me by the way

 

[kscooby28]

Re: Sport jet 120 help

my trigger is ok the ohms were all about 800. the strator is confusing cause my clymer manual shows it to have completely different color wires than it does. out of my strator its got 4 wires, 2 yellow, a wht/grn and a tan/green. the 2 latter plug into what looks like a small battery pack also the wire colors change in the input. my tan/grn plug into a wht/grn and my grn/ wht plug into a grn/ wht. out of the battery pack i have a black ground, blue and blu/wht whick plug into corrosponding color wires that go to the cpu.


also i tried unplugging the yellow wires... no spark, and the blk/yel again no spark.

UPDATE- hold on i found the readings from your post
http://forums.iboats.com/showthread.php?t=391134
i will try this and update again

 

[kscooby28]

Re: Sport jet 120 help

ok the resistance between the wht/grn and grn/wht is approx 700-715 ohms. i figured out all of the difference from your other post. now what? lol still no spark

 

[kend301]

Re: Sport jet 120 help

Re Ohm the trigger and post up individual readings for each test , 800 is BAD .

 

[kscooby28]

Re: Sport jet 120 help

i hate to ask but do you think its my cdi. i have read that if you try and spin it over with the plug cables unplugged that you can easily fry the cdi. i did just that when i found out that my engine had water inside, i took the cables off just kinda letting them dangle and i spun it over and over and over untill there wasnt much water coming out. is there any definitive test that i can perform to determine whether i need a new cdi. i found one on ebay for like 200 does that sound about right. seems cheap

 

[kscooby28]

Re: Sport jet 120 help

yeah my clymer manual says that they should be between 700 to 1000 ohms. the exact ohms are as followed between violet and white- 876 ohms . between brown and white/black- 878 ohms.


*** the 90hp should be between 1100 to 1400 ohms***** i have a 120

 

[kend301]

Re: Sport jet 120 help

Sorry , i was in 90 hp mode , Trigger is good , run the switchbox bias test on P. 47 of the manual .

 

[kscooby28]

Re: Sport jet 120 help

now im really confused the voltage hovered around 3 volts which is good im gonna go check again but you know i just dont know anymore dude. got any ideas??

UPDATE: actually it was about .3 to .6 volts. my bad so i guess thats bad. well let me just verify that i did this correctly. i grounded the red prong( out of my multimeter) , and ( i have a type 2 motor (bullet connectors)) disconnected the wht/blk bullet connector coming out of the cdi that goes to the trigger, plugged my black prong from my multimeter to the wht/blk wire coming from the cdi and spun the motor over. i got a .35 and voltage remained for about 10 sec after i shut the key off, slowly going down untill there wasn't any voltage. HMPH!!!!!

 

[kend301]

Re: Sport jet 120 help

Your test was done correctly , Yes you do have a bad switchbox .

 

[kscooby28]

Re: Sport jet 120 help

got a new switchbox cdi. plugged it in... awesome!!! works. took it out the last three days in a row. Performed perfect no hiccups nothing at all. used a hell of alota gas. 6gph at 4500 does that sound about right?? but other than that did some swimming and cruisin. was perfect thanks so much

 

[kend301]

Re: Sport jet 120 help

6 gph is in the middle of the road for one of these , as you tune the carbs and motor you may get it down to 5 gph but that is it at wot . I just run about 22 mph to get to my play zone then crank it up to save fuel !