Power then bogging?

[Brettbeckman]

Bought a 92 750sx have been having a ton of trouble with everything originally was in limp mode so I disconnected the temp sensor by going into the Ebox and disconnecting the leads and bypassed the water flow entirely straight from the stinger to the pisser.... gave me full rpm so that’s fixed (I think) then it was getting really hot and not pissing much out so I did all new gaskets and new rings cylinders/head/pistons look good so that’s fixed (I think)

Current problem... when I first get it started and into the water it’ll have decent power for 5 seconds or so then it just dogs out to a crawl if I pull it out of water and give it some rev’s and put it in I get power for a few more seconds then it’s gone again I rebuilt the carb and cleaned the jets changed plugs and that hasn’t helped me I also noticed the hose going from the water box to the exhaust hole seems to have melted? My dad seems to think it’s supposed to be like that but I think it could be a part of the problem maybe causing too much back pressure? I’ve been reading online non stop trying to find a solution but no luck quite yet

 

[Brettbeckman]

Also, tell us what the compression readings are in each Cylinder.

130 in each I don’t think the rings have fully set yet as I only rode for about 3 minutes before giving up for the day. Also have the carb set at what it says in the oem manual and have stock jets in it

 

[CARBONX2]

Pessure test cooling system, good chance you are leaking water into cylinder

 

[Brettbeckman]

That Hose has cancer. Replace it asap.

Or is it oily sludge? If the Hose feels dried out, crunchy and is not pliable when you squeeze it, then it's definitely bad.

Also, the Waterbox may be clogged up. Inspect and clean it. Check the entire Exhaust System all the way to the Outlet too.

Make sure all the Cooling Lines are clear. Check starting from the Pump Tap to the Exhaust Manifold plus all the other associated Cooling Hoses.

There may be Mud Daubers, Rats Nests, God knows what packed in there...

I’ll give the exhaust a good look again today and see if that could be the culprit the hose felt alright except for a few soft spots but I would assume all those *tumors* growing in it wouldn’t be from the factory so I’m gonna replace it either way I’m just seeing where I can find one other than a used one on eBay. Would taking a video of it on the river help diagnose a problem like this maybe someone would hear something I’m not?

 

[Brettbeckman]

Replaced the hose and that seemed to make a difference now if I can get it to plane usually by holding the throttle Wide open until it does (like In the video) it’ll pickup power and if I keep it above let’s say 1/3rd throttle it’ll keep me out of the water but nowhere the power it should have but on the top speed side i can hang with a square nose superjet just never really pulls hard... weird though sometimes it actually pulls decently hard and gets me out of the water quickly other times it just drags me for a full minute then decides to get moving