97 gsx cuts power at w.o.t.

[agy2k2]

Hello everyone...

I just purchased a 97 gsx model. Starts up and runs good but when I go w.o.t. it cracks power nice for a second like the RAVE valves are opening up but then it immediately cuts back down to a slower speed and wont keep accelerating almost like its bogging. If I let off the gas and go w.o.t. again it pulls again nicely but then immediately cuts back down again.

Things I've done so far: compression test shows 155/160 psi. replaced all gray fuel line with new. cleaned out the fuel filter/seperator. took carbs off and inspected/partially cleaned.

water tested, still did same thing...

After that I took apart RAVE valves. there was oil on top of diaphram leading me to believe they might be ripped. cleaned every part thoroughly and re-assembled.

water tested, still does same thing... I took the RAVE caps off again after testing and found no more oil everything still clean

any suggestions? I read people talking about the WR (water regulator) can cause power issues. Is this a possibility? How do I inspect this to make sure its properly functioning? Could it be an electrical issue with ignition or what???

Thanks!!!

 

[Dr Honda]

Did you clean the internal filters in the carbs? If not... that's the issue. Also... when fixing a ski with Tempo hose issues... you can't "Partly" clean the carbs. It needs to be 100%, and everything verified.

 

[Linescreamer]

Carbs that are inspected and partially cleaned are not rebuilt. I would make sure your carbs are set to spec. and see how it runs. If still not performing maybe a carb rebuild would be in order with a new inline fuel filter. It sounds like a fuel problem not an electrical issue.

 

[agy2k2]

Did you clean the internal filters in the carbs? If not... that's the issue. Also... when fixing a ski with Tempo hose issues... you can't "Partly" clean the carbs. It needs to be 100%, and everything verified.

Where in the carbs is this "filter"? I took both side covers off the carbs and sprayed them clean but thats as far as I got because I have no experience with carbs and didnt want to damage anything...

 

[Dr Honda]

Well... you could have caused damage. There are some Mylar parts that don't like carb cleaner. They have to come apart... all the way, and EVERYTHING needs cleaned. And now... there is a good chance that you need pump parts... and the high speed check valve.

 

[agy2k2]

Well... you could have caused damage. There are some Mylar parts that don't like carb cleaner. They have to come apart... all the way, and EVERYTHING needs cleaned. And now... there is a good chance that you need pump parts... and the high speed check valve.

could you give more info on your suggestion for needing pump parts and check valve? I'm in the dark on these two subjects

 

[agy2k2]

I took apart my water regulator and found some washers in there that I believe to not be original. Other than the thick washer at the bottom there were three other washers in there looks like someone may have put them in to keep the valve open I'm not sure. Can someone tell me if these are supposed to be in there?

After taking the WR apart and inspecting (I had to throw out the rotted clamp and I zip tied like others have done), I ran the ski out of the water hooked up to the hose with the black hose coming off of the WR disconnected to monitor water flow. There was a steady stream coming out with not much pressure at idle. When reving the motor the stream would only very slightly increase in flow. Is this normal or is it not much difference because I'm not in the water and only hooked to the hose?

Also, found a crack in the exhaust with water leaking out... could this be causing my issue?

 

[Dr Honda]

could you give more info on your suggestion for needing pump parts and check valve? I'm in the dark on these two subjects

I'm not quite sure what you are asking. BUT... the mylar parts don't like carb cleaner. (you said you opened the carbs and sprayed them) If you don't know what's internal of the carbs... then you can down-load the users manual from Mikuni. (Super BN 38/40)

 

[riding high]

These are not your ordinary carbs. You need some special tools and some expertise to rebuild these carbs properly. I would suggest that you PM Dr. Honda and make arrangements with him to rebuild the carbs for you.

 

[Dr Honda]

I took apart my water regulator and found some washers in there that I believe to not be original. Other than the thick washer at the bottom there were three other washers in there looks like someone may have put them in to keep the valve open I'm not sure. Can someone tell me if these are supposed to be in there?

After taking the WR apart and inspecting (I had to throw out the rotted clamp and I zip tied like others have done), I ran the ski out of the water hooked up to the hose with the black hose coming off of the WR disconnected to monitor water flow. There was a steady stream coming out with not much pressure at idle. When reving the motor the stream would only very slightly increase in flow. Is this normal or is it not much difference because I'm not in the water and only hooked to the hose?

Also, found a crack in the exhaust with water leaking out... could this be causing my issue?

The crack will leak water, and you need to weld it up. (it's just superficial, and it's int he jacket)


The water isn't going to change pressure, because your pump is out of the water. The garden hose isn't changing pressure.

The regulator being shimmed up is bad. That diverted all the water from the inside of the pipe, and makes it run hot.


You really need to get the manual on the ski if you expect to work on it. I'm not trying to be harsh... but you really need the manual.

 

[agy2k2]

as far as i know the ski hasnt been running hot so maybe the washers were keeping the WR wide open causing too much water flow. I put it back together without the added washers and will be cleaning the fuel selector switch and having the pipe welded up. Then water test again. If still acting up I'm going to tear the carbs apart again and actually go through them more. I'll keep this updated

Dr Honda thanks for your help so far

 

[agy2k2]

I finally got to work on the ski today. I got quite a bit done.

JB Welded the small leak in the pipe. I prepped the surface well and hoping that it holds up... we shall see

Finished replacing the couple gray fuel lines that I left, they are now completely replaced with new 1/4" fuel hose. Took the fuel selector out and cleaned/inspected. To my surprise it was not clogged up at all.

I then took the carbs back off. I did much more reading this time and found out what I needed to do from the sticky threads on this forum. Take a look at my screens. The MAG side was about 75% blocked up and the PTO side was almost 100% blocked up with debris. I cleaned them and took all parts out and cleaned all needles and all passage ways.

before

after

Will be putting the ski in water tomorrow. Wish me luck!

 

[agy2k2]

Tested the ski over the weekend. WOW!!! It runs decent now after going back through the carbs and cleaning them more thoroughly (I missed the little filters the first time as I was unaware they existed).

GPS showed 49 mph

I am getting some cavitation on take off. Wear ring seems to be the cause from what I've read. How do I check this??

 

[brock1]

get a feeler guage and check in between the impellar and the ring should be no more than .040