TxAg15
Member
Hello all,
I've been reading and researching a ton so I thought I'd make a project thread and see if I can get some insight from all the geniuses on here. I know it's a bit of a novel, but I thought it better to roll it all into one post for continuity.
I have a 2002 GTX RFI with ~130 hrs (located in Pensacola, FL) that I bought last year off of a guy who knew nothing about it. Was running fine at the time and I ran it for a couple months. Then it began to run rough and go into limp home mode. All I would do is replace the mag side plug and it would be fine again for maybe another hour or two (obviously should have fixed the issue first, but was just trying to make it through the end of the season). Then I finally got time to work on it this spring and found a completely shot battery (wouldn't even charge) so it sounds like I may have a bad rectifier? But I replaced the battery, it started right up and I took it out for a bit. Was still fouling mag side plug and not idling unless I kept a bit on the throttle. I decided to clean the rave valves and found one that was seized and another that barely moved. Disassembled, cleaned, replaced bad O rings, and they feel fine now. Pistons and cylinders looked fine (I should have checked compression and done a top end at this point, but I didn't). I checked resistance values on all the sensors in block 4 at the MPEM and all in spec. Put it all back together, ran fine on the trailer, so I ran it for maybe 1.5 hours then it was having major trouble. Opened it back up and found mag piston that looked like pics 1 and 2 with some minor cylinder scoring and pic 3 shows cylinder head damage, pic 4 shows marks on pto piston. Knew I was really screwed at this point. (A friend said it looks like it may have been detonation damage. Any thoughts?) I sent the fuel injectors off to fuelinjectorman.com thinking that may have contributed to the fouled mag plugs (and potential detonation) but haven't gotten the report back from Dale yet. I bought a WSM .25mm overbore top end and an ebay used cylinder head. And I'm having the cylinders bored by a local machine shop. Pulled the engine and opened the crank (without removing PTO flywheel) to inspect for debris and found a destroyed mag side rod bearing, tons of metal debris/shavings in the case (I'm assuming from the destroyed mag piston), and a small shaving from the brass rotary valve gear.
Few questions: any idea what caused the piston to self destruct? Would obviously like to confirm root cause before toasting another engine.
2nd: Best place or way to have the crank rebuilt? I know there's rebuild kits out there but I don't have the machine shop capabilities to check runout, etc and rebuild myself. Or should I just buy a new WSM crank?
Or even just buy an ebay refurbished engine? (don't like this one since it involves alot of trust to someone I don't know at all)
Lastly, anything else that I'm missing? Anything else to check?
I know I'll need the alignment tool to check alignment when re installing the engine, loctite 5910 (or something similar) to seal case halves, and I've read about removing the PTO flywheel and I know it'll suck if I have to.
Any help is greatly appreciated!
I've been reading and researching a ton so I thought I'd make a project thread and see if I can get some insight from all the geniuses on here. I know it's a bit of a novel, but I thought it better to roll it all into one post for continuity.
I have a 2002 GTX RFI with ~130 hrs (located in Pensacola, FL) that I bought last year off of a guy who knew nothing about it. Was running fine at the time and I ran it for a couple months. Then it began to run rough and go into limp home mode. All I would do is replace the mag side plug and it would be fine again for maybe another hour or two (obviously should have fixed the issue first, but was just trying to make it through the end of the season). Then I finally got time to work on it this spring and found a completely shot battery (wouldn't even charge) so it sounds like I may have a bad rectifier? But I replaced the battery, it started right up and I took it out for a bit. Was still fouling mag side plug and not idling unless I kept a bit on the throttle. I decided to clean the rave valves and found one that was seized and another that barely moved. Disassembled, cleaned, replaced bad O rings, and they feel fine now. Pistons and cylinders looked fine (I should have checked compression and done a top end at this point, but I didn't). I checked resistance values on all the sensors in block 4 at the MPEM and all in spec. Put it all back together, ran fine on the trailer, so I ran it for maybe 1.5 hours then it was having major trouble. Opened it back up and found mag piston that looked like pics 1 and 2 with some minor cylinder scoring and pic 3 shows cylinder head damage, pic 4 shows marks on pto piston. Knew I was really screwed at this point. (A friend said it looks like it may have been detonation damage. Any thoughts?) I sent the fuel injectors off to fuelinjectorman.com thinking that may have contributed to the fouled mag plugs (and potential detonation) but haven't gotten the report back from Dale yet. I bought a WSM .25mm overbore top end and an ebay used cylinder head. And I'm having the cylinders bored by a local machine shop. Pulled the engine and opened the crank (without removing PTO flywheel) to inspect for debris and found a destroyed mag side rod bearing, tons of metal debris/shavings in the case (I'm assuming from the destroyed mag piston), and a small shaving from the brass rotary valve gear.
Few questions: any idea what caused the piston to self destruct? Would obviously like to confirm root cause before toasting another engine.
2nd: Best place or way to have the crank rebuilt? I know there's rebuild kits out there but I don't have the machine shop capabilities to check runout, etc and rebuild myself. Or should I just buy a new WSM crank?
Or even just buy an ebay refurbished engine? (don't like this one since it involves alot of trust to someone I don't know at all)
Lastly, anything else that I'm missing? Anything else to check?
I know I'll need the alignment tool to check alignment when re installing the engine, loctite 5910 (or something similar) to seal case halves, and I've read about removing the PTO flywheel and I know it'll suck if I have to.
Any help is greatly appreciated!
