1998 GSX Limited....Mid throttle problems

[Tailgate4jc]

First off thanks for all you help to come.

I have this GSX now for 3 years. I have changed the gray fuel lines to true black fuel lines. I have removed the small filters in the carbs and cleaned and rekitted the carbs. I have an inline filter along with the factory water separator/screen. Ok so what is my problem. When I put this thing in the water man it runs great for about 20-25 mins then looses mid throttle. It idles fine and a little throttle is fine. Up till about 3000 rpms. Then more throttle makes it really bog down. If you hold it wide open sometimes it will take off. Like wide open runs. Seems to run fine at fill throttle. It likes to go fast.

Ok on a side note Im not sure if the lines to the tank are plumbed correctly. When I fill it up with fuel it will start leaking fuel out the side port. I thought since it did that the vents might not be correct. When it starts this bogging down I tried opening the cap to let air to no help. I have the manuals but its not real clear on the plumbing of the fuel lines.

Any help on either of these problem and I hope they are connected is great appreciated. I love all the information on here and so much of it has helped. I am so glad there are so many comments of the gray fuel lines. My were nasty and the screens where plugged.

 

[Dr Honda]

I would double check the bypass ports in the carb... and make sure the settings (pop-off, high/low needles) are to spec.


But... since it will run for a while, and then start to give issue... I'm almost thinking it's either electrical, or it's overheating, and getting tight.

If you pull in the throttle, and it's bogging........ if you pop the choke... will it come to life, or does it get worse??

 

[Tailgate4jc]

Hey thanks for you help.

Now when its doing its bogging trick I do pull the choke out and it does get worse. I don't think that its a heat problem, I have taken the seat off when its doing this so I can "watch" inside. It does not see to be any hotter than normal. You can touch it and yes its warm but not like extremely hot.

So what part of the electrical do you think it might be? I have new plugs in it. I have not changed the wires but I could with my other machine. Just to see if there is a difference.

 

[bhatch21]

Could the RAVE valves being stuck closed cause this condition? Don't they open around 4000rpm? Just and idea.

 

[Tailgate4jc]

I have checked both of the rave valves and they are free and movable. Not sure how they operate on pressure but I do know they move.

Today as my son was driving it and complained that smoke was coming from the hood. when I popped the seat off the hull was full of smoke. I did smell it and it was exhaust thank goodness. So the exhaust clamp was very loose. then nut had back off and there was a space between the collector and the pipe. So with a wrench and full of hope I tightened it. The hope didn't help as much as the wrench did. It still bogs down. Its just aggravating to want to ride and it wont run like you want.

Thanks for you help and an opinions are welcome.

 

[SabrToothSqrl]

Step 1 is a compression test. An engine is just an air pump. If you don't have compression, you don't have an engine.

 

[Tailgate4jc]

So I guess what need to do is compare cold compression to hot. I know its not a air pump to start with because it runs great to start with...for the most part. Also I runs at top speed when it gets there. So for an air pump man its great.

So yes maybe a compression test would be nice but I would bet I need one during the problem time.

Thanks and Ill think more about this as well.

 

[RebuiltSeadooBaffles]

You dont compression test a hot motor, compression test the motor cold, both plugs out and holdiing throttle wide open

 

[SabrToothSqrl]

It would still be a valid test.

He is attempting to compare the compression hot and cold. not compare it with another ski.

If, say hot, the compression is substantially less in one cylinder, it would still indicate an issue.

 

[mikelly]

I am having the same problem with both of my GTX LTDs, new motors, lines etc. no mid range, either slow or "throw you off the seat" fast cleaned the rave valves ,runs fine for 30 mins, then it starts to bog and have no mid range, everything is clean

 

[Tailgate4jc]

Maybe we can get a two for one fix. I really hope someone can come up with idea for us to try. Im listening to anything that someone has to offer. I haven't checked the compression yet but with you having new engines in it I would guess its not a compression problem either.

I know when I throttle it hard it does smoke and it smells like its running rich. I cant help but think its a carb problem. So please if anyone has a suggestion let me / us know.

 

[SabrToothSqrl]

All of this sounds like fuel issues. However, again, check the compression. Then I'd move on to the fuel lines and carbs.