Thread: Low end bog problem modded gsx
08-17-2009, 04:53 PM #1
- Join Date
- Mar 2009
- Ballston Lake
Low end bog problem modded gsx
I have a 97 GSX 787 with a low end bog problem. I have a FP spec 2 and msd water injection with stock carbs. Grey lines replaced and carbs are rebuilt with filters cleaned. The ski doesnt wanna go past 3500rpms and just bogs down the entire time. Occasionally I can get it past 3500 rmps and it will get up and go but it seems like it only gets goin when the water injection kicks on fully. Also when I switch the fuel selector to off for about 3 seconds the back to on it kicks up to speed again. Once i am passed 3500 it will say running good. Ski still needs some tuning for the setup but this problem has stopped progress. Im gonna pull selector valve this week but figured I would get some opinions. Thanks guys.
08-17-2009, 05:29 PM #2
are you running a hard jetted waterbox? have you talked to Wayne lately?
08-18-2009, 10:51 AM #3
- Join Date
- May 2007
One of my skis is very similar, GSX +porting, Novi carbs, etc.
I've had similar issues on my 787 motors, what I found;
1. Clogged filter screens inside the carbs, this has happened a few times over the years. Unless you replace EVERYTHING, that goo from the gray lines hangs around for a while
2. A bad rectifier can cause some of those symptoms
3. Burned PTO piston, it would rev up but no have enough to get out of the water.
08-18-2009, 02:39 PM #4
Dude let me tell ya from experience a spec 2 will eat that rear piston if you don't have those carbs dialed in perfect... Also clean that selector switch real good. On a spec 2 i always run on reserve and nothing else. I run one line from the tank reserve stem to my fuel pump and the return line back to the tank and a vent line that's it. No fuel bowl up front or a selector switch. I took out the chance for an air leak.
Pull the fuse for the ecwi solenoid and see if your boat runs better.
Also what hard jetting are you using in that boat. The spec 2 has thread to except mikuni jetting in the ecwi,mid pipe spray bar and if you have a stinger. I would get rid of the water regulator if you still have that on your waterbox and hard jet that with a jet works valve inline to spray at about 4200.
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