ATS_Aaron
X-
- Location
- Shady Shores, TX
WTF!! I am furious.
My crank let go back in October and I didn't miss a beat getting parts shipped to "capable" shops to get it repaired. I should have just sent the whole thing to Chucky at X-Scream, but I tried to save a buck and sub-contract the stuff out myself.
I ordered Wiseco pistons and sent the cylinder, crank, crank bearings, and new Wiseco's to Pro-Tec. They sat on it for nearly 2 months before telling me they were unable to disassemble the crank. They also said my bore didn't clean up enough for the 85mm Wisecos to work. So they sold me a set of 85.5mm Pro-X cast pistons.
They sent my cylinder and crank back. I sent the crankshaft to Crankworks. They did a good job; they promised it in 3 weeks and finished it in 4 weeks. Not too bad. I got the whole thing cleaned up, assembled and running by the end of February.
I took it out on it's first run for <30 minutes on March 5th. Everything went fine except for a plug wire I forgot to firmly click down.
The next outing was ~March 12th. The water was still cold so we got in less than 1.5 hours of riding. We were jumping the wake behind my new Toyota Epic boat. Not too much wide open throttle, mostly just playing around. Ski ran fantastic with no problems at all.
I wanted to go again around the end of March, but the rest of the gang couldn't get their crap together. I did go out and start my ski for a few seconds to make sure it was ready to go. It fired up after some priming and settled to a nice idle. I blipped it and I thought the throttle stuck. It revved up, but sounded for lack of a better term FLAT. The kill switch wouldn't stop it. I held the kill switch and pumped the primer until it died. Classic lean condition/air leak, right?
I fired it up again and it revved fine, no overrev/stock throttle/flat sound. It started , revved, idled, and died no problem. My guess at the time was that it started on the primer gas, but the carbs didn't fill up with fuel for a few seconds and it was revving on a lean condition caused by empty carbs, and that once they filled up it wouldn't happen again.
So we had some great weather today and decided to hit the lake. I went out to check on my ski and make sure the battery was charged. It took some priming, but it started. I blipped it a second and it stuck. Same flat lean sound. I held the kill switch and went WOT it and it died.
BTW it doesn't rev up to redline, kind of a mid-high rpm, but not max rpm stick. If you pull the throttle it will rev higher, but it won't fall back to a nice idle.
I thought it would stop like it did before, but no luck.
I tried to narrow it down to one cylinder, so I removed the plug wire from the front cylinder and ran it, same with the back. It runs fine on one cylinder and will not over-rev.
We grabbed the air compressor and decided to do a leak test on the engine. I capped off the exhaust and carbs and we filled the hull with water up to about the shafts of the carbs. I put 8 psi on the fuel pump pulse line to the crankcase.
NO BUBBLES
We'll almost no bubbles. After a few seconds I saw a tiny one pop out of the rear crank seal, so where near enough to cause this problem.
I am telling this story out of order a little, but apparently my gas tank vent check valve may have also failed. I noticed that when I pulled the return line the tank released some pressure.
At this point I started to wonder if I lost a cylinder head o-ring. So we pulled the head. O-rings look fine, but that is when I realized that my cylinder with < 2 hours on it looks like total %^$#@! It is scored up like a seizure victim. WTF? Was it about to seize each time it did it's air-leak over rev? But there was no air leak? Could it have been caused by excessive pressure in the gas tank? How was the gas tank building up pressure (I'd say 1-2 psi) in less than 10 seconds of running?
Both cylinders are scored, the rear one is worse and the dome of the rear one is dark grey like METAL residue.
So THANKS if you have read this far.
My best guess is that something has failed on my back carb's fuel pump and it is somehow using the pulse signal from the crankcase to pressurize my fuel tank. My tank is set up as dual feed (one off the ON, and one off the RESERVE) and I noticed one of the filters was not filling up as quickly as the other.
Not knowing is the worst.
Aaron
My crank let go back in October and I didn't miss a beat getting parts shipped to "capable" shops to get it repaired. I should have just sent the whole thing to Chucky at X-Scream, but I tried to save a buck and sub-contract the stuff out myself.
I ordered Wiseco pistons and sent the cylinder, crank, crank bearings, and new Wiseco's to Pro-Tec. They sat on it for nearly 2 months before telling me they were unable to disassemble the crank. They also said my bore didn't clean up enough for the 85mm Wisecos to work. So they sold me a set of 85.5mm Pro-X cast pistons.
They sent my cylinder and crank back. I sent the crankshaft to Crankworks. They did a good job; they promised it in 3 weeks and finished it in 4 weeks. Not too bad. I got the whole thing cleaned up, assembled and running by the end of February.
I took it out on it's first run for <30 minutes on March 5th. Everything went fine except for a plug wire I forgot to firmly click down.
The next outing was ~March 12th. The water was still cold so we got in less than 1.5 hours of riding. We were jumping the wake behind my new Toyota Epic boat. Not too much wide open throttle, mostly just playing around. Ski ran fantastic with no problems at all.
I wanted to go again around the end of March, but the rest of the gang couldn't get their crap together. I did go out and start my ski for a few seconds to make sure it was ready to go. It fired up after some priming and settled to a nice idle. I blipped it and I thought the throttle stuck. It revved up, but sounded for lack of a better term FLAT. The kill switch wouldn't stop it. I held the kill switch and pumped the primer until it died. Classic lean condition/air leak, right?
I fired it up again and it revved fine, no overrev/stock throttle/flat sound. It started , revved, idled, and died no problem. My guess at the time was that it started on the primer gas, but the carbs didn't fill up with fuel for a few seconds and it was revving on a lean condition caused by empty carbs, and that once they filled up it wouldn't happen again.
So we had some great weather today and decided to hit the lake. I went out to check on my ski and make sure the battery was charged. It took some priming, but it started. I blipped it a second and it stuck. Same flat lean sound. I held the kill switch and went WOT it and it died.
BTW it doesn't rev up to redline, kind of a mid-high rpm, but not max rpm stick. If you pull the throttle it will rev higher, but it won't fall back to a nice idle.
I thought it would stop like it did before, but no luck.
I tried to narrow it down to one cylinder, so I removed the plug wire from the front cylinder and ran it, same with the back. It runs fine on one cylinder and will not over-rev.
We grabbed the air compressor and decided to do a leak test on the engine. I capped off the exhaust and carbs and we filled the hull with water up to about the shafts of the carbs. I put 8 psi on the fuel pump pulse line to the crankcase.
NO BUBBLES
We'll almost no bubbles. After a few seconds I saw a tiny one pop out of the rear crank seal, so where near enough to cause this problem.
I am telling this story out of order a little, but apparently my gas tank vent check valve may have also failed. I noticed that when I pulled the return line the tank released some pressure.
At this point I started to wonder if I lost a cylinder head o-ring. So we pulled the head. O-rings look fine, but that is when I realized that my cylinder with < 2 hours on it looks like total %^$#@! It is scored up like a seizure victim. WTF? Was it about to seize each time it did it's air-leak over rev? But there was no air leak? Could it have been caused by excessive pressure in the gas tank? How was the gas tank building up pressure (I'd say 1-2 psi) in less than 10 seconds of running?
Both cylinders are scored, the rear one is worse and the dome of the rear one is dark grey like METAL residue.
So THANKS if you have read this far.
My best guess is that something has failed on my back carb's fuel pump and it is somehow using the pulse signal from the crankcase to pressurize my fuel tank. My tank is set up as dual feed (one off the ON, and one off the RESERVE) and I noticed one of the filters was not filling up as quickly as the other.
Not knowing is the worst.
Aaron
