Hello: I'll state my problem first: Engine starts up instantly. It runs great for just a couple of minutes. Good idle, good midrange and super good punch when WOT. But within 1-2 minutes it has power loss and can only be ran 1/2 throttle or engine bogs. It starts and idles fine, but continues to have more power loss till it won't get up on plane without stalling. Engine feels warm but I can still keep my foot in pisser water. Seems like a fuel delivery problem. Or ignition problem when hot...
Now I will give you the background info. so you can best point me in the right direction. I will paypal one person $25 for the solution that fix's my problem. I am desperate to get this fixed before the 4th of July weekend.
I installed a new SBT premium engine package for my 1993 Kawasaki 750ss, and installed the injector block off plate. Mixed the SBT break in oil with amoco ultimage gas. I rebuilt the single kehein carb with SBT carb kit, and installed new pump diaphrams after buying special non removable star bolt screwdriver...etc...
New engine started within a minute. It appears to idle a bit rougher or have more vibration than last motor. Icreasing the engine idle rpm did smooth this out a bunch, but still appears to idle with more vibration than before. PTO to driveshaft alignment appears very straight.
I rode 1/2 tank of fuel at 1/2 throttle on first outing. The next day out, I rode 1/2 to 3/4 throttle for the remainder of the fuel tank. No bog issues what so ever.
3rd day out now using 40:1 mixture of amoco ultimate and yamaha semi synthetic premix. (I will switch to fully synthetic after 20 hours and rings have seated).
When full throttle was applied ski didn't have the punch it used to. I adjusted the hi needle richer and bingo, the ski had more punch. It had a hesitation between low and hi so i played with the lo needle till I made it to rich and it bogged a bit down low... I screwed it back in until it ran good both down low and up high. I rode for a good 5 minutes and everything felt GREAT. That's when the bogging started.
It started to bog and have trouble getting into higher speeds. I adjusted the jets in / out but could not overcome bog. After sitting for 5-10 minutes the jet ski initially pulls strong, but quickly bogs at 1/2 throttle or above.
I brought it home and started from the gas tank to the sediment bowl, to the valve, to the fuel intake of carb. All lines free and clear. I removed and inspected the fuel pulse line. Pulled return line off and started engine.. fuel is returning to tank. I did find some sediment in the fuel pickup line on the ON unit, which I removed with air pressure. Jet ski bogs whether on ON or RES fuel selector. I also blew out the pickup unit on RES line. Both pickup units were plastic and about 2 inches long. Neither had screens on them. Both lines are made of steel and flow freely... Air blown into them comes out strong at the other end.
Question... My sediment bowl is empty. Bone dry. Is this a problem? I also inspected check valve on top of gas tank to the upper vent line. no blockage, and when blowing and sucking, the check valve lets air in toward the tank, but not out or towards to the top vent... is this correct?
I added an inline filter during engine swap between gas valve and carb intake. I can see fuel immediately fill up when engine starts. When I blip the throttle, I see a few bubbles in the clear filter, but filter remains full of gas. I use this same type and brand of filter on all my motorcycles with no problems. Do Jet skiis have a problem with fuel filters effecting flow? I could remove and splice line together with 1/4 " fitting...
I have pulled plugs and they read a bit lean. I replaced and still engine bog. I have checked compression and have 150 and 148. I checked spark with a spark tool and both will throw spark a solid 1/2 inch...
I removed carb and fully disassembled agian. Everything looks perfect, clean, all passages perfect. I am using longest or lightest spring on pop off valve and have adjusted the correct amout of gap. I do not have vacum tool to test pop off pressure. Could this be my problem? Why does it run fine till hot, then bog.
The ski starts the second you touch the start button. It runs fine, and revs smoothly on trailer with water line hooked up. At the lake, it starts and idles fine in water. After a 1 minute warm up, it takes off with full power! Runs great. No hesitation. Smoothe transition low to high. Then I let off gas and turn around a couple hundred yards out... it has trouble getting back up to WOT... but runs good at 1/2 throttle... I get back to boat ramp... It is now bogging alot anytime over quarter throttle. If I give it WOT it dies. Starts and idles fine. Fuel starvation???
Please help. How do I test further. How to I test coil, stator etc...
Should I remove carb and intake and inspect reeds. They are original but had no gaps upon reinstall to new engine.
Thanks a million for reading this long post. I am trying to give you all the info. to get the best advice. I have planned a huge 4th of July weekend at the lake and need the ski.
Call or email me directly or post here if you can to help me out. I will Pay $25 bucks to the one who solves my problem!!!
Tom Wirth
319-551-3540
wirth315@aol.com
More info.
Nothing is stuck in my impeller. I can remove the plugs and freely spin the pump shaft with my hand. Out of water I can blip the throttle and send water shooting out 10 feet.
Could temp sensor be the culprit and can I bypass it for a lake test?
One more note: When is driveway with water hose... engine runs, easily feels like it revs good with minimal throttle. Engine exhaust manifold never gets hot. I can keep my hand on it... In the water at the lake... this is very hot. I can keep my hand on it but it is hot.
That's everything I can think of. Is this electrical or fuel??? Please help.
Thanks
Now I will give you the background info. so you can best point me in the right direction. I will paypal one person $25 for the solution that fix's my problem. I am desperate to get this fixed before the 4th of July weekend.
I installed a new SBT premium engine package for my 1993 Kawasaki 750ss, and installed the injector block off plate. Mixed the SBT break in oil with amoco ultimage gas. I rebuilt the single kehein carb with SBT carb kit, and installed new pump diaphrams after buying special non removable star bolt screwdriver...etc...
New engine started within a minute. It appears to idle a bit rougher or have more vibration than last motor. Icreasing the engine idle rpm did smooth this out a bunch, but still appears to idle with more vibration than before. PTO to driveshaft alignment appears very straight.
I rode 1/2 tank of fuel at 1/2 throttle on first outing. The next day out, I rode 1/2 to 3/4 throttle for the remainder of the fuel tank. No bog issues what so ever.
3rd day out now using 40:1 mixture of amoco ultimate and yamaha semi synthetic premix. (I will switch to fully synthetic after 20 hours and rings have seated).
When full throttle was applied ski didn't have the punch it used to. I adjusted the hi needle richer and bingo, the ski had more punch. It had a hesitation between low and hi so i played with the lo needle till I made it to rich and it bogged a bit down low... I screwed it back in until it ran good both down low and up high. I rode for a good 5 minutes and everything felt GREAT. That's when the bogging started.
It started to bog and have trouble getting into higher speeds. I adjusted the jets in / out but could not overcome bog. After sitting for 5-10 minutes the jet ski initially pulls strong, but quickly bogs at 1/2 throttle or above.
I brought it home and started from the gas tank to the sediment bowl, to the valve, to the fuel intake of carb. All lines free and clear. I removed and inspected the fuel pulse line. Pulled return line off and started engine.. fuel is returning to tank. I did find some sediment in the fuel pickup line on the ON unit, which I removed with air pressure. Jet ski bogs whether on ON or RES fuel selector. I also blew out the pickup unit on RES line. Both pickup units were plastic and about 2 inches long. Neither had screens on them. Both lines are made of steel and flow freely... Air blown into them comes out strong at the other end.
Question... My sediment bowl is empty. Bone dry. Is this a problem? I also inspected check valve on top of gas tank to the upper vent line. no blockage, and when blowing and sucking, the check valve lets air in toward the tank, but not out or towards to the top vent... is this correct?
I added an inline filter during engine swap between gas valve and carb intake. I can see fuel immediately fill up when engine starts. When I blip the throttle, I see a few bubbles in the clear filter, but filter remains full of gas. I use this same type and brand of filter on all my motorcycles with no problems. Do Jet skiis have a problem with fuel filters effecting flow? I could remove and splice line together with 1/4 " fitting...
I have pulled plugs and they read a bit lean. I replaced and still engine bog. I have checked compression and have 150 and 148. I checked spark with a spark tool and both will throw spark a solid 1/2 inch...
I removed carb and fully disassembled agian. Everything looks perfect, clean, all passages perfect. I am using longest or lightest spring on pop off valve and have adjusted the correct amout of gap. I do not have vacum tool to test pop off pressure. Could this be my problem? Why does it run fine till hot, then bog.
The ski starts the second you touch the start button. It runs fine, and revs smoothly on trailer with water line hooked up. At the lake, it starts and idles fine in water. After a 1 minute warm up, it takes off with full power! Runs great. No hesitation. Smoothe transition low to high. Then I let off gas and turn around a couple hundred yards out... it has trouble getting back up to WOT... but runs good at 1/2 throttle... I get back to boat ramp... It is now bogging alot anytime over quarter throttle. If I give it WOT it dies. Starts and idles fine. Fuel starvation???
Please help. How do I test further. How to I test coil, stator etc...
Should I remove carb and intake and inspect reeds. They are original but had no gaps upon reinstall to new engine.
Thanks a million for reading this long post. I am trying to give you all the info. to get the best advice. I have planned a huge 4th of July weekend at the lake and need the ski.
Call or email me directly or post here if you can to help me out. I will Pay $25 bucks to the one who solves my problem!!!
Tom Wirth
319-551-3540
wirth315@aol.com
More info.
Nothing is stuck in my impeller. I can remove the plugs and freely spin the pump shaft with my hand. Out of water I can blip the throttle and send water shooting out 10 feet.
Could temp sensor be the culprit and can I bypass it for a lake test?
One more note: When is driveway with water hose... engine runs, easily feels like it revs good with minimal throttle. Engine exhaust manifold never gets hot. I can keep my hand on it... In the water at the lake... this is very hot. I can keep my hand on it but it is hot.
That's everything I can think of. Is this electrical or fuel??? Please help.
Thanks
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