Super Jet Help please Fast!!!!!!!!!!!

[lcgordon]

Im supposed to go riding tomorrow and i have a 94 superjet 701 with a wamaltons girdled high comp head on it. Its supposed to be set at 185 comp but one cyl has 160 and the other has under 50. But it runs fine, it starts fine it does not seem to have any problems. I just was board and thought i would check it for fun. Is something wrong would a ski with a cyl with only 50 psi in it seem to run ok or is it my comp tester. thanks for the help.

 

[TITAN]

If it runs fine I would assume it would be the tester. Check another motor with it.....

 

[lcgordon]

Ok well it seems to run fine in the garage and it rode ok the last time i had it on the lake. It would almost not go if it was like 40 psi right.

 

[btmboards]

the big thing is that it rode fine last time you had it out. my buddy acually had a similar issue with a different two stroke last weekend. started up, reved great, and took off but was slow as could possably be with absolutly no power whats so ever once a load was put on it. kinda killed the day a bit. After getting it back to the house, he checked compression and it was somewhere between 40 and 50psi. Granit that was with a single cylinder motor but the affects would be similar just not quite a drastic do to you have another cylinder to try to carry the extra load. So when you drop it in the water, if it isnt as peppy as normal, Id say you have an issue. If it is, Id say recheck and if same compare with another ski.

 

[lcgordon]

well my scupper leaked last time i rode it and sunk my ski but i rode it the next day after getting all the water out and it seemed to ride fine

 

[lcgordon]

then it died in the middle of the lake but then the battary was dead i think i ran it so low the day before getting all the water out then my bildge pumps were running alot when i rode it that my battary went dead i dont think its cuz of the engine. But now it sound and starts up great.

 

[RoscoeJ]

spray some wd40 in cylinder ,and crank with no plug ,could be a stuck or sticking ring...make sure your compression tester is the right one ,meaning the same length threads as your plug ,if your tests are consistant its a stickingor stuck ring or your o-ring head leaking...oh I didnt see... you have a sinker..salt or fresh sinker?

 

[lcgordon]

ok if i run the ski will it hurt it

 

[RoscoeJ]

No It wont ..Just spray a shot in there and crank with the plugs out ,let it sit in there 15-30 mins before you try to crank it ,then crank it with the plugs out for 10 secs, then recheck compression.

 

[Rickster]

Take the head off and have a look inside... I would say you have more happening than a "stuck" ring...

 

[RoscoeJ]

Do you ride in fresh or salt water?

 

[lcgordon]

fresh water

 

[RoscoeJ]

Thats good ,are you going to try to fix it now? or tommrow. If tommrow I'll check post for update.

 

[lcgordon]

tomorrow its too late tonight im supposed to ride tomorrow at like 5 so i got a little bit of time and thanks so much for the help i know some stuff about motors but im not a mechanic so im learning as i go and you guys help alot with different tricks

 

[NVJAY775]

Take the head off and have a look inside... I would say you have more happening than a "stuck" ring...

X2 From the difference in psi I would guess oring in the head / head gasket. Pray that's it. I baked a cyl over memorial day and had almost the same readings on comp. But so did my son with a blown head gasket. Hope for the best. Plan for the worst.

 

[RoscoeJ]

I will check back tommrow ,I'm replacing a 701 61x from my blaster with a 760 62t dual carb, just finished the carbon fiber work , and installing the thru hull exhaust ,cant wait to ride it! but I'll be back on tommrow,be patient..

 

[lcgordon]

Thanks man ill update tommorro and one thing i have a stock head could i put that on i have 62t cylinders bored a lil bit and its a stock blaster head i think is made for a 61x cyl

 

[RoscoeJ]

Thanks man ill update tommorro and one thing i have a stock head could i put that on i have 62t cylinders bored a lil bit and its a stock blaster head i think is made for a 61x cyl

61x head has a single water inlet ,are you running dual coling lines now for your setup?
It all depends on your current setup ,if its a stock enging with just a larger bore ,it should be fine , When was the last time you changed the O-rings in your head ?

 

[lcgordon]

i have had the ski for a little over a week so i have not touched anything but the guy i bought it from said he rebuilt it last year

 

[RoscoeJ]

i have had the ski for a little over a week so i have not touched anything but the guy i bought it from said he rebuilt it last year

Let me know if compression is the same after the Shot of wd.