superjet 701 rev issue

L

lysygda

Location
poland
Hello everyone!
I have SJ 701 motor and have no idea what's going on. It's won't rev at all, on a trailer or in water, strats great and idle perfectly. I replace: sparks, stator with coils, ignition coil, cdi module, checked compression, clean and replace carb's kits, checked ignition settings. I don't have any more ideas what i can do to fix the problem. Can anyone help me?
 
smoofers

smoofers

Rockin' the SQUARE!!!!
Site Supporter
Location
Granbury, TX
Did you check your pop-off pressure when you rebuilt the carburetors? Are you running the stock flame arrestor(s) or aftermarket? If your pop-off is excessively high you'll never rev past idle.
 
SuperJet-Dave

SuperJet-Dave

Location
Rochester, NY
lysygda said:
Hello everyone!
I have SJ 701 motor and have no idea what's going on. It's won't rev at all, on a trailer or in water, strats great and idle perfectly. I replace: sparks, stator with coils, ignition coil, cdi module, checked compression, clean and replace carb's kits, checked ignition settings. I don't have any more ideas what i can do to fix the problem. Can anyone help me?
Click to expand...

Could also be a bad/clogged fuel filter. Try removing the in-line fuel filter near the fuel tank, and see if it rev’s.
Less likely, but could check the pulse line to see if if has any small cracks, and is secured tightly on both ends.
Good luck.
 
L

lysygda

Location
poland
Hello, thanks for answers! I checked everything what You say. I have stock flame arestor, it os matter? I have gold spring for 1.5 needle so Maybe it is to high? It’s open aabout 40psi .
 
E350

E350

Site Supporter
Location
Sacramento Delta
1. Is your fuel tank check valve functioning properly to prevent a vacuum from occurring in the fuel tank?
2. As stated are your in-carb fuel filters clean?
Note: On the 1994 SN SJ, the oem fuel return line was deteriorating leaving fuzzy black debris in the filter both in the carb and in the tank.
Both of these caused similar symptoms in one of our single carb 701.
 
Last edited:
DylanS

DylanS

Gorilla Smasher
Location
Lebanon Pa
Have you tried putting fuel right down your carbs and opening the throttle to see if it will rev? Then you’ll at least know if it’s a fuel delivery issue or ignition issue.
 
E350

E350

Site Supporter
Location
Sacramento Delta
DylanS said:
Have you tried putting fuel right down your carbs and opening the throttle to see if it will rev? Then you’ll at least know if it’s a fuel delivery issue or ignition issue.
Click to expand...
That is exactly how I determined I had a fuel delivery problem. The ski wouldn't rev up when I pulled the throttle, but when running when I would add gas using the primer plunger, the ski would rev up - thereby indicating that the engine was suffering from a lack of adequate fuel delivery.
 
L

lysygda

Location
poland
Hi! thanks for all answers! I tell You what's going on.

I get superjet 701 I guess. There is factory b-pipe and tuned head(mx100). I get it with broken stator coils, starter and it's gear. I replace them. I put coils exactly like old (timing). Checked carbs (dual 38), replace spring and pop off valves and repair sets. replace sparks, igniiton coil, cdi module. Check engine leakage, copression test. everything is ok. I have no idea what's going on but when it start it do not rev at all. I set timing by 1 degree in both side. I cut fuel lines and get it from bottle with no filters etc. There is one thing i do not touch. Its high and low carbs screws. But if it working before i guess it ok. Maybe i should adjus them?
 
Daytona Nick

Daytona Nick

Location
Daytona Beach, FL
lysygda said:
Hi! thanks for all answers! I tell You what's going on.

I get superjet 701 I guess. There is factory b-pipe and tuned head(mx100). I get it with broken stator coils, starter and it's gear. I replace them. I put coils exactly like old (timing). Checked carbs (dual 38), replace spring and pop off valves and repair sets. replace sparks, igniiton coil, cdi module. Check engine leakage, copression test. everything is ok. I have no idea what's going on but when it start it do not rev at all. I set timing by 1 degree in both side. I cut fuel lines and get it from bottle with no filters etc. There is one thing i do not touch. Its high and low carbs screws. But if it working before i guess it ok. Maybe i should adjus them?
Click to expand...
Take your fuel pump off on back side of carb and check flaps and make sure your pulse line is in the right spot
 
L

lysygda

Location
poland
Take your fuel pump off on back side of carb and check flaps and make sure your pulse line is in the right spot
Click to expand...
I checked pulse and pump in carbs and its ok.
I think i checked everything. Maybe someone can tell me how to adjust high and low screws. Maybe it’s a clue ;)
 
DylanS

DylanS

Gorilla Smasher
Location
Lebanon Pa
lysygda said:
I checked pulse and pump in carbs and its ok.
I think i checked everything. Maybe someone can tell me how to adjust high and low screws. Maybe it’s a clue ;)
Click to expand...
Low speed adjustment screw is used to set idle and high speed is for Full throttle. Neither of them will stop your ski entirely from revving up, and if you’re putting fuel into the motor with a spray bottle and it STILL won’t rev up you have a electrical issue. Fuel, compression… that leaves ignition. Have you tried a known working Cdi? Pink wire not grounded out in ebox??
 
Daytona Nick

Daytona Nick

Location
Daytona Beach, FL
It's should be fear low speed jet should be about one and a half out near high speed jet should be about two turns out from closed near low on your low speed jet you want to adjust turn in until it starts to almost sound like it's running away then turn back out a 1/4 turn high set is trial and error into your plugs look good after a couple with pulls should snap right off of idle and rev up or you more then likely have cdi problem
 
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