90 sport jet power loss

Joined
Jul 4, 2010
Messages
24
I have a 93 Baja Blast that ran great two weeks ago however today when tring to go to wot it would rev up then act like it was starving for fuel. It will run at about 3/4 throttle anymore and it lugs and if you turn to the right it cuts out like a lack of fuel. Had fuel pump rebuilt a about a month ago. It has cdi
 

kend301

Lieutenant Junior Grade
Joined
Jul 4, 2009
Messages
1,005
Re: 90 sport jet power loss

Check fuel flow from the pump , take the feed line off the cars tree at the bottom and put it in a glass jar an watch flow , It should be steady , not pulse . Pull the air box and be sure the carbs are not flooding , if they are first check the vent tubes on the side of the carbs with lines coming out of them , they must be unobstructed ! If you can not blow through the vent tubes the carbs can not vent and will vapor lock running you out of gas . If all that looks good , take the boat out run it until it cuts off and pull the plugs and see if they are wet with fuel or dry
 
Joined
Jul 4, 2010
Messages
24
Re: 90 sport jet power loss

Ok I have replaced fuel lines and added a elactric fuel pump for testing flow.It was worse after that so I pulled out the meter and got the following
Black stator:(:(
Blue to Blue/white 588
red to red/white 31
rev lim
Yellow to yellow 1861
Trigger wite/blk as ground
to brown 984
to purple 987
to white 985
I also have two coils with broke mags
I don't know if this is worth fixing or not what would I need as parts go. I do still have spark on all three plugs
 

kend301

Lieutenant Junior Grade
Joined
Jul 4, 2009
Messages
1,005
Re: 90 sport jet power loss

Proper stator testing for the Black stator on a 90 HP is as follows ?

2 yellow wires on the stator side of the harness .. .06 to 1.1 ohms is spec
Ohm between red and blue ... 3600 to 4200 is spec
Ohm between red and ground , spec is 90 -140 ohms.

BUT the wire colors you are posting says one of two things
1 you have a 120 HP 4 cylinder, Not a 90 HP 3 cylinder
2 You have a 120 hp stator on a 90 hp motor

If you do indeed have a 120 ignore the above tests and post up so I can give you the proper test for a 120 .
If you have a 120 stator on a 90 I think we have found your problem .
 
Joined
Jul 4, 2010
Messages
24
Re: 90 sport jet power loss

Sorry for the long wait but I have been busy and just began working on this boat again. I have replaced all three coils and checked fuel flow. I used a ohm meter to check the trigger and stator I have no spark on the bottom cyl. I have unhooked the two yellow from rev limiter and still no fire. I got the following readings from white/blk to brown 994 to purple 998. To white 994. Blue to blue striped 592 and whit to red 31.3 I have now pulled the flywheel and found a broke mag. I know the colors are off but I have CD I p/n 174-8778k1 and p/n 134-7029-3 I need help trying to figure out what I need
 

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Joined
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Re: 90 sport jet power loss

And a few more because we all like pics
 

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moonbuggy

Cadet
Joined
Feb 25, 2011
Messages
16
Re: 90 sport jet power loss

:confused:Not sure if this helps but, the two yellow wires are coming out of your Regulator/Rectifier. Your Rev Limiter is located on the front of the motor, below and to the left of the carbs and has: brown, purple and black w/yellow striped wires coming out of it;).
 
Joined
Jul 4, 2010
Messages
24
Re: 90 sport jet power loss

Yes I am trying to figure out the stator I know kend301 runs cdi I think either my stator or trigger is the cause of no fire on #3
 

kend301

Lieutenant Junior Grade
Joined
Jul 4, 2009
Messages
1,005
Re: 90 sport jet power loss

stator is a 174-8778-k1 cdi , go to www.cdielectronics.com and find that stator and click on installation instructions or trouble shooting . and ohm specs will be there .. Btw you have the OLD voltage regulator , time to upgrade .
 
Joined
Jul 4, 2010
Messages
24
Re: 90 sport jet power loss

Update it is back running strong. I tested eveerytthing and all showed good so l decided to take some emery cloth and clean on the stator very little sandding and they were back bright white reassemabled and good spark on all cyl. I put it in the lake came up on plane with no trouble. Thanks for everyone's help.
 

philly5eagle

Seaman Apprentice
Joined
Jun 5, 2010
Messages
47
Re: 90 sport jet power loss

Question for you, what did you do about the broken magnet on the flywheel? Did you just epoxy it back together or did you replace the flywheel?
 

philly5eagle

Seaman Apprentice
Joined
Jun 5, 2010
Messages
47
Re: 90 sport jet power loss

I just used epoxy and let it set up for a couple of days
Just the answer I was looking for. I have another thread on here about my motor, I'm working on boring one of the cylinders etc and one of my other problems was a piece of one of the magnets that broke off. I was hoping to just epoxy the magnet back together and was wondering if it would work. Hearing that yours is now running like a champ is great news (for you and me!) Thanks for the reply!
 
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