Super Jet rpm problem

alme7airbi_h · May 1, 2023

hey guys

i have superjet 701 2008 the rpm should be at 9-10k but when i rev it it only reach about 3-4k
found a video that has the same problem:

engine modes:
high comp head
msd ignition
factory b pipe

john zigler · May 1, 2023

The ski in the video is dropping a cylinder (Spark wise).

Yours may be doing the same thing. We have MANY problems with the MSD Cdi's, could also be the ignition coil, plug boots, fouled spark plug, etc. I have even had a bad voltage regulator cause this.

alme7airbi_h · May 1, 2023

john zigler said:
The ski in the video is dropping a cylinder (Spark wise).

Yours may be doing the same thing. We have MANY problems with the MSD Cdi's, could also be the ignition coil, plug boots, fouled spark plug, etc. I have even had a bad voltage regulator cause this.

thank you, i will check them

kevbo · May 1, 2023

alme7airbi_h said:
hey guys

i have superjet 701 2008 the rpm should be at 9-10k but when i rev it it only reach about 3-4k
found a video that has the same problem:

engine modes:
high comp head
msd ignition
factory b pipe

RPM 9k-10K? Why so much over rev?

alme7airbi_h · May 2, 2023

kevbo said:
RPM 9k-10K? Why so much over rev?

i bought the ski like this, how much should it be

john zigler · May 2, 2023

JC-SuperJet said:
@john zigler

Any suspicions on how the Voltage Regulator/Rectifier would cause intermittent spark?

All I know is on more than one occasion we have had Yamaha's here that are in a "limp mode" like the overheat sensor is bad, only to find it was the VR causing the rpm limit.

I will say, this is WITH a stock Cdi though.

kevbo · May 2, 2023

I would set the limit no higher than 500 rpm over what it runs on smooth water. Racers may benefit from a little more but they do a lot of bad things to their engines trying to beat the guy next to them.

bird · May 3, 2023

kevbo said:
I would set the limit no higher than 500 rpm over what it runs on smooth water. Racers may benefit from a little more but they do a lot of bad things to their engines trying to beat the guy next to them.

Bro can't even get his ski running and you're telling him how to Race and set Rev Limiters

Do the simple thing and swap spark plug wires, front to back, back to front. Does the other cylinder go bang? Does the ski still sound the same.

alme7airbi_h said:
i bought the ski like this, how much should it be

Most 701s are pulling 7000-8000 rpms.

alme7airbi_h · May 9, 2023

bird said:
Most 701s are pulling 7000-8000 rpms.

soo 8500 should be good right?