rotary valve

  1. Just Luv Workin on Skis

    Puzzling Rotary Valve & Rotary Shaft Brass Gear Failure

    My 1997 Sea Doo SPX was running great for quite some time. One day after a couple of hours on the lake it just wouldn't start. There was no big noise or anything to make me believe something had gone wrong. The photos show a small nick out of the edge of the rotary gear and several teeth...
  2. Elster

    Rotary valve surface damage?

    hello guys, I would like if anyone could criticize this Rotary valve surface. Because there is missing some metal near by one of the inlet holes. Do you think this engine could run good with this damage? With kindly regards, Elster
  3. CreekerMike

    Seadoo 720 weird oil leak

    Greetings and salutations to all. I got my factory piped 720 assembled and installed this past weekend. I dont have the necessary carbs yet however so its not 100%. I fired it a few times on starting fluid to show some of my buddies. Sadly I saw oil in the hull (this was after an engine out...
  4. S

    Which Rotary Valve do I need!?

    I recently picked up a non running 94 XP with a 657X. The motor was toast, and the guy i bought it from gave me an extra engine that he was under the impression was a good engine, i went ahead and threw a new top end kit in the new engine before putting it in the ski. The original engine that...
  5. Sebastian Bluecrew

    Can't find THE answer, Rotary Valve 720

    Hey guys. New to the forum, but I have read the forum for years.. Long story short.. I have a 1997 Seadoo SP with a 720... Completely rebuilt, new everything, overbore 1.0mm, Factory Performance Pipe spec 1 with ECWI and rev limiter, Solas 16/24 Concord, AND, dual 40mm carbs... So the stock...
  6. RogerS

    Parts Beware

    DONT BUY rotary valve from “bay area motorsport” on EBAY! Just got my new valve and wont fit! I have to hammered down use a screwdriver to push the notches into place... and it is little thicker than the original... making loud noise and pressure.... i using my old one...
  7. 6

    97 XP 787 - Will a bad DESS post cause backfiring and resulting engine damage?

    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...
  8. alx401

    need help with rotary valve 94 657x

    installed rotary valve using 149 and 65 degree. Problem is the plate will not line up on both. its at least 10 degree diffrence. Should i split the diffrence and both marks be off a little or one side dead on?
  9. alx401

    94 657x rotary valve not linig up

    According to specs manual timing marks should be at 149 and 65. When i install at 149 the other side is bout 10 degree off. It lines up at bottom of valve opening at about 55 degree. Seems like 130/65 works better but this is definitly a 657x engine. Is there something i am doing wrong. Ive...
  10. B

    97 xp 787 rotary valve prob?

    I had to remove my rotary valve cover to tap stripped out carb bolt. The actual valve itself had grooves in it and a small knick on the edge (looks like it had swallowed a bolt at some time - I can see a matching knick on the pto opening on the engine block). So I replaced with a new valve...
  11. lswaffield

    oil injection lines on 787 to manifold/rotary valve

    I am going to change the two lines coming from the oil pump given the hose fitting popped out of the oil pump. It appears that I have two inline check valves on both lines from the oil pump to the rotary valve on both intakes. I don't see these on any schematics of the systems. If I replace...
  12. G

    Rotary Valve Cover Uneven Wear?

    Hello All, I have a 2002 GTI LE into which I'm swapping a new SBT 717, but I'm a bit worried about the rotary valve cover. It isn't gouged or grooved anywhere, and the surface seems relatively smooth, but it seems to be wearing unevenly. Looking at the outside edge, the surface appears worn...
  13. benstoker

    rotary valve crankcase grooves

    Hey everyone. I recently bought a 94 gtx fixer upper and have just pulled the engine on it. When I removed the carbs and rotary valve case, I noticed a chunk was missing from the rotary valve. The case looks fine (no grooves or anything) but the crankcase side is all sorts of grooved. From what...
  14. chrisdeamicis

    Thanks to the forum & a compression question that's likey already been answered.

    I was having starting problems with my 97 Gti. I haven't worked on 2 strokes much and was having a hard time figuring is out. Would run good the first run but after shutting it down, would always have a hard time getting it to start again. Would always eventually fire up and then run good but...
  15. moto17

    Rotary valve 787 Questions

    I just put in an new SBT 787 in my (1997 Challenger with one 787) jet boat and new carbs as well! Sooo the timing seems to be still off....I learned how to do it on this site and put in a new rotary valve form WSM ? hmmm it wont line up exactly right? it seems to be off just a little bit. The...
  16. U

    96 GTI Rotary Problems

    I was out on the lake and my seadoo was making a funny noise then it just died. Could never get it started again. I finally pulled the carbs to check the floats and noticed that a bolt was missing. The bolt fell and messed up the rotary plate (see picture). I was hoping I had found my...
  17. N

    Dreaded 4000rpm wait 4-8 seconds then goes Fast!

    93 Seadoo XP 657 I'll start here.. Fresh engine. New crank New pistons New Rotary Valve New Rotary shaft new impeller new wear ring Rebuilt carbs Mukini kits Black fuel lines with inline filter right before carb I lined up the Rotary valve with the mark on the...
  18. T

    98 gti 717 rotary cover???

    My rotary valve is shot and it notched out the cover. the crankcase is fine(or seems to be). where can I get the valve and cover and what are the part numbers for these parts? Ive looked through the shop manual and cant find part numbers for parts only tools. what could have caused this to happen??