im trying to get this thing out the door for a customer but i can't get it to run right it will idle fine then when u punch the throttle it will hessitate then run fine then fall on its face at top end??????? it is jetted to what my spec book says...160 mains and 80 pilots........and the high speed screws at 1.25 turns out and the lows 0 for mag and .25 for pto i tried backing out the lows and it seemed to help but not enough...what should the low and high speed screws be set at? the only mods are aftermarket flame arrestors......
-
This site contains eBay affiliate links for which Sea-Doo Forum may be compensated.
gsx limited running problem
- Thread starter xprider02
- Start date
- Status
robin savell lloyd
Active Member
Sounds like screws are bacwards low should be about 1 1/2 and high 0.
:agree: Robin is correct. The Highspeed screw should be at "0" The lowspeed screw (it has a pin through it) Should be set at 1 1/2 as a starting point. Both carbs should be set the same, Mag and PTO. Let us know how you make out.
Karl
Karl
sorry I meant to say I have the low speed screws at 1.25 turns out and the highs set at 0 for mag and .25 for pto now both of the highs are at 0 but anyway now the thing hesitates and lacks power when u punch the throttle then it will take off and do fine kinda like it is cavitating but it also feels like the engine hesitates when you corner. I thought it was maybe a driveline issue but the jet pump is all put together correctly...would a problem with the rave valves possibly cause this? there is only one spring in each rave valve on this 951 correct? i am new to the 951 engines so any advice or comments would be greatly appreciated
It could be the RAVE valves. Yes, only 1 spring is in them. Here is a good explaination.
The RAVE, (Rotax Adjustable Variable Exhaust) valves are located above the exhaust valve. There are 2 of them per engine. They are round with a red adjustment screw in the middle. It has a clip that holds it together. How they work is that they open the exhaust port larger as the engine rpm's increase. When the rpm's drop down so do the RAVE valves. They work on the principle of the pressure of the exhaust system. Rpm's increase, pressure increases and the valve opens, rpm's drop pressure drops, Valve closes. They should be de-carbonized annual. To disassemble the rave valves, remove the spring clip on top, remove the black cover. There is a spring under the cover. Remove the piston by turning it with a metric socket. On the bottom of the piston is the rubber "Bellows" be careful with the small retaining spring that hold the bellows on the piston. Remove the 2 allen screws that hold the base on the cylinder. Remove the base and gasket. The long valve won't fall in the cylinder just pull it out. There is an o ring under the base, on the shaft of the guillotine valve. Be careful to see how it came apart as it has to go back together that same way again. On the base, notice the notch that it is facing down. Clean all the carbon off the guillotine valve. I use carb cleaner and 400 grit paper. Check the bellows for any small pin holes. If so replace it. If not, reassemble it on the clean guillotine valve, and install it back on the engine the same way it came apart. The guillotine valve only fits one way. The one closest to the exhaust pipe will come off differently then the other one. You will have to remove the allen screws and turn the base so it clears the exhaust pipe. I would do one at a time in case you forget how it goes back together again. This way you can look at the other one and copy it. Do both engines 2 per engine. Take your time and if you have questions give us a shout. We'll be here to help you out.
If the RAVE valves are dirty it will not rev up correctly and could be causing your problem.
Keep me posted on you progress.
Karl
The RAVE, (Rotax Adjustable Variable Exhaust) valves are located above the exhaust valve. There are 2 of them per engine. They are round with a red adjustment screw in the middle. It has a clip that holds it together. How they work is that they open the exhaust port larger as the engine rpm's increase. When the rpm's drop down so do the RAVE valves. They work on the principle of the pressure of the exhaust system. Rpm's increase, pressure increases and the valve opens, rpm's drop pressure drops, Valve closes. They should be de-carbonized annual. To disassemble the rave valves, remove the spring clip on top, remove the black cover. There is a spring under the cover. Remove the piston by turning it with a metric socket. On the bottom of the piston is the rubber "Bellows" be careful with the small retaining spring that hold the bellows on the piston. Remove the 2 allen screws that hold the base on the cylinder. Remove the base and gasket. The long valve won't fall in the cylinder just pull it out. There is an o ring under the base, on the shaft of the guillotine valve. Be careful to see how it came apart as it has to go back together that same way again. On the base, notice the notch that it is facing down. Clean all the carbon off the guillotine valve. I use carb cleaner and 400 grit paper. Check the bellows for any small pin holes. If so replace it. If not, reassemble it on the clean guillotine valve, and install it back on the engine the same way it came apart. The guillotine valve only fits one way. The one closest to the exhaust pipe will come off differently then the other one. You will have to remove the allen screws and turn the base so it clears the exhaust pipe. I would do one at a time in case you forget how it goes back together again. This way you can look at the other one and copy it. Do both engines 2 per engine. Take your time and if you have questions give us a shout. We'll be here to help you out.
If the RAVE valves are dirty it will not rev up correctly and could be causing your problem.
Keep me posted on you progress.
Karl
no the rave valves are clean i already cleaned them....I did file down them b/c i put over sized pistons in it hopefully i didn't file them too much i don't think i did though b/c i only took off maybe a half of a millimeter....the thing runs great out of the water it is only when there is a load on it
I would check the wire connections and be sure it has a good ground- and a good positive+ connection first. Make sure the battery is charging. Use a multi meter on the battery when it isn't running( should be like 12.4 volts. Than start it up and see if the voltage goes up to like 14.3 or close to that. If it doesn't budge than it isn't charging. The fuse that controls it is in the MPEM box. It is a 15 amp fuse off the wire from the solenoid to the MPEM that also connects to the + of the battery.
Karl
Karl
I checked the charging and it is running at about 13.5vdc and goes up to 14.35vdc or so when you rev it up so obviously the stator is good and the battery...I also checked out the rave valves and noticed that on the mag side one the rubber boot was worn out and not letting it move up and down properly....is there a test for the solinoid that tells the rave valve to open or close? also what should the compression be on this engine? thanks for all your help I know I have a lot of questions haha
Ok first the clearance of the gap between the impeller and the wear ring is .040" (about 1/16" visual). It sounds like it doesn't have a charging problem...The Bellows, (rubber boot)needs to be replaced if it is worn. The compression should ideally be 150 psi. per cylinder. If they are close to each other than thats ok, like 120 psi each. They need to wear at the same rate. If they are 130 psi and 90 psi... then you need to refresh the top end. I'll look into the solenoid test of the RAVE valve.
Karl
Karl
seadoolover
New Member
hoses to RAVES?
Hey Karl... does this 98 gsx have hoses to the raves or are they mechanically operated? If it has hoses.. check all hoses to RAVES for blockages.
Hey Karl... does this 98 gsx have hoses to the raves or are they mechanically operated? If it has hoses.. check all hoses to RAVES for blockages.
- Status
