Super Jet 62T Electronics driving me crazy

JT_Freeride

JT_Freeride

John Tetenes @Jtetenes
Location
Long Island
Hey guys i have been having a problem with my ski and im just looking for some help from the jetski gods.

Its a RN 701 62T
riva red pipe
Ada head 35cc domes 185 psi both cylinders
carbs specs

2.0 n/s
135 main
75 pilot
high 1.5
low 1
Pro-K F/A

Im Gonna start from the very beginning this ski has not been running up to its full potential since i put the pipe and head on. first problem i had was my carbs they where so out of whack i used WSM stuff and i will never use them again my pop off was 22 in one and 28 in the other and im sure the jets probably weren't actually the correct size. Ryan put all new mikuni stuff in and when i put the carbs on my ski it didn't quite run right so he informed me to put 130 mains back in and i did so and it ran great but no matter where i put the high speed screws it didn't seem to make a difference (plug color was actually perfect all the time). after that i went to the surf again and it was running like crap and ryan gaped my plugs real tight (i was told this was a sign of a bad stator) and this seemed to fix it and then once again the ski ran great. now like 1 month later the ski starts acting up again it would run great in the begining of the day and about 1 hour later the ski would fall on its face and as if it ran out of fuel. turns out my return line on the slave carb was clogged which makes me believe that was the reason for the 130 jets and why the high speed screws didnt matter. so i went ahead and put a new return on the carb from a slave that we had laying around ( this returns outlet is angled on a 90 and also its a bigger fitting not sure if this matters). after that i ran the ski on the trailer and it ran away so put the 135s back in and it didnt run away. i would like to add when the ski is on the trailer is revs fine and sounds fine. now thinking all is well i throw it in the water and hope for the best but of course is runs worse and now it sounds like its on 1 cylinder but will randomly take off like a bat out of hell. at idle in the water it feels great crack the throttle and it falls on its face. Now going back to the bad stator i bought a good used stator and coil and swapped them. guess what didnt fix the problem. I tested the stater and coil using the specs from the Tech FAQ and they check out i was unable to check the pulsar coil because i have a digatil meter but when i did i get 2.4 and 4 ohms which is still withing spec. But both coils tested different resistance the old coil was 4.3k which is correct and the new coil was 19k strange. its should be within 3.5k-4.7k .
The only thing i have not changed out is my CDI but im told they either work or they dont.
Any insight is greatly appreciated Brigantine is coming up and i need this thing to work lol

Thank you, John
 
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Proformance1

Proformance1

Liquid Insanity
Location
New York Crew
swap out for a complete know good ebox from a running ski of a good friend. Or keep one on hand like I always do for just such issues. that way you can rule out and move on. Stock CDI is fine for test box. Call JM and order the whole thing and be done with the chasing. I know it can be frustrating. I have done a bunch. Assuming you have stock 38s for carbs, the pop off is low IMO
 
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BruceSki

BruceSki

Formerly Motoman25
Location
Long Island
Youve got a friend indeed. I have an entire 61X set of electronics you can try if you want. Bring your ski by my house after we ride today. I'm tearing apart that XL760 tonight anyhow so I'll be out there.
 
JetManiac

JetManiac

Stoked
Site Supporter
Vendor Account
Location
orlando
Several things:

-change N&S back to oem size 1.5 and HS jet back to 135. Also 95g springs for use a/m f/a with 1.5

-slave 38 carb has a restictor in it to regulate fuel pressure, that is what got plugged. Make sure the back you used has this same sized restrictor or your fuel pressure will be off.

-dont know if you have electrical issues as well, but get carbs right first.
 
sjetrider

sjetrider

615 Freeriders are addicted to T1 madness.
Location
in the 615 (Nashville)
The MOST common issue I see in saltwater conditions ends up being in the start stop switch. Have you ever tried disconnecting the black and white plug (stop side) on your ss switch and turning idle down? These switches absolutely HATE saltwater. They have a history of doing fine then after a few minutes going to shizot.
Also, something simle but worth checking is the fuel tank preasure valve.
If your stator ohms out correctly and your coil checks consiston OHM wise (regardless of what it is as long as it doesnt change when flexed) some coils have copper and some fiber wires (fiber 760 coils are best for salt water) so they may ohm different. So if you have no issues ohming these and wiggling the wires on both stator and coils while ohming then they are fine, quit looking at them.
Try the ss switch trick next, if it runs the same move on and have a fuel tank check valve with you. Try it.
Next for me is checking the exhaust flow, sounds crazy but make sure waterbox is good, no loose parts inside and make sure no kinks in the rubber hoses. Trust me, easy check and I have chased those issues for months never imagining they were an issue.
If you have good consistant spark on both plugs then your next step should be trying another cdi. Rare but possible that they can go bad without going out and its an hr to find out.

Remember you need the following
Air flow
fuel flow
compression
exhaust flow
spark
timing

start with one, eliminate it, go to the next and be prepared to check and try all the easy things your first trip to the water after eliminating the ohm checking and compresion checking and so forth of the major components in the shop.
run it with the hood off for a while as well, sometimes things happen ony when in the water and riding that you will not see on the trailer running.

Hard to diagnose a boat on a discription in a thread but these are the things I try based on previous history of simular issues.
Its quick and easy to check most of these things.
 
JT_Freeride

JT_Freeride

John Tetenes @Jtetenes
Location
Long Island
JetManiac said:
Several things:

-change N&S back to oem size 1.5 and HS jet back to 135. Also 95g springs for use a/m f/a with 1.5

-slave 38 carb has a restictor in it to regulate fuel pressure, that is what got plugged. Make sure the back you used has this same sized restrictor or your fuel pressure will be off.

-dont know if you have electrical issues as well, but get carbs right first.
Click to expand...

Thanks i currently went back to 1.5 n/s and 95g springs pop off is a 42 for both, also im going to find another return because this one seems to be way bigger
 
JT_Freeride

JT_Freeride

John Tetenes @Jtetenes
Location
Long Island
sjetrider said:
The MOST common issue I see in saltwater conditions ends up being in the start stop switch. Have you ever tried disconnecting the black and white plug (stop side) on your ss switch and turning idle down? These switches absolutely HATE saltwater. They have a history of doing fine then after a few minutes going to shizot.
Also, something simle but worth checking is the fuel tank preasure valve.
If your stator ohms out correctly and your coil checks consiston OHM wise (regardless of what it is as long as it doesnt change when flexed) some coils have copper and some fiber wires (fiber 760 coils are best for salt water) so they may ohm different. So if you have no issues ohming these and wiggling the wires on both stator and coils while ohming then they are fine, quit looking at them.
Try the ss switch trick next, if it runs the same move on and have a fuel tank check valve with you. Try it.
Next for me is checking the exhaust flow, sounds crazy but make sure waterbox is good, no loose parts inside and make sure no kinks in the rubber hoses. Trust me, easy check and I have chased those issues for months never imagining they were an issue.
If you have good consistant spark on both plugs then your next step should be trying another cdi. Rare but possible that they can go bad without going out and its an hr to find out.

Remember you need the following
Air flow
fuel flow
compression
exhaust flow
spark
timing

start with one, eliminate it, go to the next and be prepared to check and try all the easy things your first trip to the water after eliminating the ohm checking and compresion checking and so forth of the major components in the shop.
run it with the hood off for a while as well, sometimes things happen ony when in the water and riding that you will not see on the trailer running.

Hard to diagnose a boat on a discription in a thread but these are the things I try based on previous history of simular issues.
Its quick and easy to check most of these things.
Click to expand...


Thanks Sjet i seem to have left out some of the procedures that i have eliminated.
S/S switch is a kawi style switch because all the yamaha switches i have had just go bad right away also the ski doesnt die it just falls on its face and returns to a idle speed and when i hit the throttle it chokes it out.
My tank has pressure that was the first thing i checked and i even pluged my RES line straight to the carb to eliminate Petcock and fuel filter as well as carbs have a fresh rebuild. Im gonna have to try that exhaust thing because my riva pipe seems to kink my hose. and also i good CDI
 
BruceSki

BruceSki

Formerly Motoman25
Location
Long Island
And stay away from the 760 coils. I tried one after hearing how good they were and it made my boat act up for months last year and the beginning of this. Put a wet jet coil in with long wires and I've been good since then.
 
sjetrider

sjetrider

615 Freeriders are addicted to T1 madness.
Location
in the 615 (Nashville)
WOW, that is good info. We always had issues with OEM 701 coils but ONLY in surf, changed to 760 coils and issues stopped.

I am sure fiber wires break down as well so may have just been a bad one?

I have been on TL for a while now so that was back in the day.




BruceSki said:
And stay away from the 760 coils. I tried one after hearing how good they were and it made my boat act up for months last year and the beginning of this. Put a wet jet coil in with long wires and I've been good since then.
Click to expand...
 
BruceSki

BruceSki

Formerly Motoman25
Location
Long Island
sjetrider said:
WOW, that is good info. We always had issues with OEM 701 coils but ONLY in surf, changed to 760 coils and issues stopped.

I am sure fiber wires break down as well so may have just been a bad one?

I have been on TL for a while now so that was back in the day.
Click to expand...

I very we'll might have had a bad one. It worked good for a few rides then started acting up. Would run on one cylinder, cut out then run. I changed plugs and it would go away. Then surface on a great wave day and run like crap again. One of the old gurus we ride with saw me cutting back plug wires on the beach and said "get that 760 fiber junk outta there, that's your problem". Been good ever since the swap.

I chased that demon for a while and just finally replaced the coil and it runs like a top again.

Half my problem is I am cheap and keep running 20 year old electronics off part out skis though. I am my own worst enemy with that. I should really buck up and just buy a whole brand new electronic system so that I don't end up chasing electrical gremlins.
 
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