New SBT engine broke down SD 720

[gary Surak]

I have swaped 720 SD '97 engine for a SBT. I did install the RV at 147 degrees as the book says. Switched to premix, left all the installation as if the pump was there with the oil tank 3/4 full. In the break in process I got only to 20 min idle. The engine died on me. I tried several times to restart it unsuccesfully. Towed back and called the SD mechanig who was questioning as to why there is a resistance to a rotating the shaft with removed plugs and he suspected the RV. Removed the carbs and removed RV cover to find out that the axle that rotates the RV does not rotate with the crankshaft (or has great delay) and he says it is brass gear inside. I applied pleeeenty of oil before assembling it,used SBT break in oil at even more that 40:1 ratio in premixture and this thing died on me. I called Phil at SBTand they will inspect the motor. Does anyone have a clue as to why did this happen? Bill, any thoughts? Could I have something that caused this? One more thing: I did replace the RV cover with SBT and installed new RV.

[Bill O'Neal2]

Re: New SBT engine broke down SD 720

I guess you were just one of the lucky ones :) Sometimes things just do not work right and need to be exchanged for one that does. It happens to the best of us.

[gary Surak]

Re: New SBT engine broke down SD 720

And to make the things even worse I carried the engine in my suitcase on the plane to Europe where I planned to enjoy this summer. Now I have to bring it back and ship it to Clearwater, they will inspect it and tell me their opinion, then back to Mediterranean. What a venture and it is the end of July. Also I used all the break in oil for the premixture. The inspection at the airport does noit permit oil on the plane but I managed to somehow bring it in my suitcase. What if I am not succesfull this time? Should I use some other oil for break in. There is a MOTUL brand available there. Any suggestions, just in case?

[Bill O'Neal2]

Re: New SBT engine broke down SD 720

Any two stroke oil will work.

[gary Surak]

Re: New SBT engine broke down SD 720

Phil (the inspector) at SBT asked me how much oil did I leave in the oil tank and when I responded I left about half to three quaters he said that might not have been enough since only gravity is what feeds the oil to the RV. Could that be my fault??? Can the engine start even if the RV is not installed at the exact angle?I was also told that the oil has to be SPECIAL that cost much more than just any two stroke oil.

[frankey01]

Re: New SBT engine broke down SD 720

the one good thing Gary is that you have a fault frww warranty meaning even if it was your fault they will replace it free.

[1fastski.com]

Re: New SBT engine broke down SD 720

3qts would have been plenty for the rotory gear , for break in just use the same oil you use to run the ski with . its possable it was a failure due to a defect , you also will want to see if theres any bends or groves in the rotory valve , you could have droped a washer in { many do it } and not seen it .

why cant you ship the engine back and have somone ship it back to you ?