If you don't want to read my long winded story below then please just answer the following question: Can a bad DESS post cause the engine to backfire while riding in the upper RPM range, push out and bend the rotary valve, scrape up the RV cover, and then cause the engine to quit?
If you want to read on below is my long story below!
I bought a 97 XP last year cheap and as expected (with cheap) it has been a project with numerous problems. When I bought it, it would start fine on the trailer but was almost impossible to start in the water. I changed fuel lines, cleaned out the tank and put in new gas and took the carbs apart and cleaned them but it didn't make a difference. I got lucky and it started once in the water and to run pretty good but I only ran it around the boat landing for 5 minutes and then put it away for the winter. The previous owner told me about the hard starting on water and also said he would get it out on the lake and it would quit and not start again for the rest of the day but would then start again the next day. It didn't quite on me but I only road it for a brief time.
Fast forward to this year, I took the carbs apart again and this time replaced the diaphragms, filters, and some O-rings, checked the pop off, and put the carbs back to together. I also took the RV cover off and found out it had been gouged up before and then cleaned up and put back together. It was in really bad shape with lots of clearance where the cleaned up the gouges. After a new RV and cover I put it together and the first time out on the lake it started up like a champ! Unfortunately, about 1/2 a mile down the lake it started cutting out and then quit. I never could get it to start or even fire that day no matter what I tried including dumping a bit of gas in the cylinders. The next time I worked on it I found some pieces of rubber in the bottom of the fuel bowl which I had cleaned before running it. I figured the shut off valve may have come apart insider and possibly plugged itself up since I know it would only turn with pliers. I bypassed it w/o ever fully removing and testing it and it started up (but probably would have anyway). I got it running and took it to the lake and it would not start in the water. I put some new plugs in and then it started and ran fair but didn't see 100%. I started running it down the lake and it sounded like it may have backfired out the carbs a couple times. I thought it was gonna 'clear up and run better but instead...it quit and wouldn't start. I also noticed that sometimes it would turn over when I hit the starter button and other times it would 'catch' and not spin. I took the carbs and RV cover off and found a bend in the leading edge of the RV and another gouged up cover. I then took the head off and found a banged up piston top and head but it does not appear to have seized like I expected. Is it possible the backfire bent the RV and the RV would then catch sometimes when I tried to start it? Also, if the backfire could not bend the RV then did something get spit out of the engine? I would like to know why it quit the first day even though it started and ran awesome briefly. Also, what caused the back fires? I only question the DESS because it seems like sometimes I would here the two beeps when I put un the DESS cap and other times I would not. Here are the pics. I think the cylinders will be fine with a hone and the RV will probably be Ok if I address the small bend spot. I may also flip it so that is the trailing edge. I just don't know if I can get away with cleaning up the case where the RV rides and the RV cover or if it will not run good with them. I also don't know if the head was clean or dinged up some before since it had been removed before and the RV, case, and cover had been damaged and cleaned up before. I do plan to take the bottom end apart to see how much wear the crank, balance, and RV shafts have on them. I think this ski has a lot of hours on it and it has probably had a top end rebuild before but not a bottom end. Compression was 120 in both cylinders before I ran it this year and 115 in one side and 60ish in the other after the 2nd outing when it backfired and quit. What do you all think and what would you do. I will add another post with pics. Thanks
If you want to read on below is my long story below!
I bought a 97 XP last year cheap and as expected (with cheap) it has been a project with numerous problems. When I bought it, it would start fine on the trailer but was almost impossible to start in the water. I changed fuel lines, cleaned out the tank and put in new gas and took the carbs apart and cleaned them but it didn't make a difference. I got lucky and it started once in the water and to run pretty good but I only ran it around the boat landing for 5 minutes and then put it away for the winter. The previous owner told me about the hard starting on water and also said he would get it out on the lake and it would quit and not start again for the rest of the day but would then start again the next day. It didn't quite on me but I only road it for a brief time.
Fast forward to this year, I took the carbs apart again and this time replaced the diaphragms, filters, and some O-rings, checked the pop off, and put the carbs back to together. I also took the RV cover off and found out it had been gouged up before and then cleaned up and put back together. It was in really bad shape with lots of clearance where the cleaned up the gouges. After a new RV and cover I put it together and the first time out on the lake it started up like a champ! Unfortunately, about 1/2 a mile down the lake it started cutting out and then quit. I never could get it to start or even fire that day no matter what I tried including dumping a bit of gas in the cylinders. The next time I worked on it I found some pieces of rubber in the bottom of the fuel bowl which I had cleaned before running it. I figured the shut off valve may have come apart insider and possibly plugged itself up since I know it would only turn with pliers. I bypassed it w/o ever fully removing and testing it and it started up (but probably would have anyway). I got it running and took it to the lake and it would not start in the water. I put some new plugs in and then it started and ran fair but didn't see 100%. I started running it down the lake and it sounded like it may have backfired out the carbs a couple times. I thought it was gonna 'clear up and run better but instead...it quit and wouldn't start. I also noticed that sometimes it would turn over when I hit the starter button and other times it would 'catch' and not spin. I took the carbs and RV cover off and found a bend in the leading edge of the RV and another gouged up cover. I then took the head off and found a banged up piston top and head but it does not appear to have seized like I expected. Is it possible the backfire bent the RV and the RV would then catch sometimes when I tried to start it? Also, if the backfire could not bend the RV then did something get spit out of the engine? I would like to know why it quit the first day even though it started and ran awesome briefly. Also, what caused the back fires? I only question the DESS because it seems like sometimes I would here the two beeps when I put un the DESS cap and other times I would not. Here are the pics. I think the cylinders will be fine with a hone and the RV will probably be Ok if I address the small bend spot. I may also flip it so that is the trailing edge. I just don't know if I can get away with cleaning up the case where the RV rides and the RV cover or if it will not run good with them. I also don't know if the head was clean or dinged up some before since it had been removed before and the RV, case, and cover had been damaged and cleaned up before. I do plan to take the bottom end apart to see how much wear the crank, balance, and RV shafts have on them. I think this ski has a lot of hours on it and it has probably had a top end rebuild before but not a bottom end. Compression was 120 in both cylinders before I ran it this year and 115 in one side and 60ish in the other after the 2nd outing when it backfired and quit. What do you all think and what would you do. I will add another post with pics. Thanks
