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yamaha 1200 engine failure

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  • yamaha 1200 engine failure

    Well, i finally got my Yamaha 1200 put back together and may have a problem. I rebuilt the top end and carbs. The engine fires right up and sounds good, however i noticed that the power valves are not moving. Here's my question. Should the power valves be moving at idle or only when under a load? This may be a dumb question but i just don't know much about these valves. Any help will be greatly appreciated.
    Thanks, Angus


  • #2
    Re: yamaha 1200 engine failure

    I believe they open in the mid 3000 rpm range
    I once thought having a 6 figure income would be great,, now I have a 6 figure income TAX , wats up with that!!

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    • #3
      Re: yamaha 1200 engine failure

      Thanks for your reply Jeff. The shop manual says to hook a 12 volt lead to the red and black leads on the motor and then momentarily jumper a wire from the black to grey leads. I did this and nothing moved, is my motor shot?
      Thanks, Angus

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      • #4
        Re: yamaha 1200 engine failure

        you totally lost me with that why would a motor be shot if the power valves are not opening ??? power valves can cause engine trouble but you said you rebuilt the engine
        I once thought having a 6 figure income would be great,, now I have a 6 figure income TAX , wats up with that!!

        Comment



        • #5
          Re: yamaha 1200 engine failure

          Sorry about that Jeff. What i was trying to say is i did the test on the power valve servo motor and got no response.
          Thanks,
          Angus

          Comment



          • #6
            Re: yamaha 1200 engine failure

            I don't know anything about power valves, but if they're only involving exhaust and the engine is running fine then I would be out on it with the seat off hauling and seeing if they move.

            Just putting in my 2 cents

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            • #7
              Re: yamaha 1200 engine failure

              Seems like i've finally resolved all the issues i've had with this project. This thing runs like a rocket! I just want to once again say thanks to all you guys for your help with this. I started rebuilding this waverunner without any experience at all with these machines. I've had a ball doing this and it was a great winter project. Once again, thanks. Now it's time to turn this thing over to my grandson.......
              Angus

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              • #8
                Re: yamaha 1200 engine failure

                Glad you fixed your problem. Powervalves only open up at higher RPMs. When you turn your engine off they should also cycle through once or twice.
                2012 Yamaha 242 Limited S
                97 Monterey Montura 186 3.0L Volvo Penta SX (sold)

                Comment



                • #9
                  Re: yamaha 1200 engine failure

                  What model do you have? GPR, XLT, or XLL? There are some things you must know about those specific hulls. I wrote up a review posted on pwctoday.com:

                  http://www.pwctoday.com/f14/gpr-xlt-...ps-112129.html

                  I'll copy and paste it here for you as well:

                  There's a few things you should know about an GPR, XLT, or XLL before you purchase one as they have a few issues that need to be addressed.

                  1) Powervalves- If you own any Yamaha 800cc ski, any XLT, or an 00 to 04 GPR, then you have a powervalve engine. It's not uncommon for these skis to drop a powervalve pin into a cylinder. If this occurs, you'll most likely destroy the engine. The most common and practical precaution is to purchase a set of Waveeater powervalve clips and couplers. Another, more costly, option is to buy gas powervalves.

                  You can purchase Waveeater powervalve clips and couplers from this link below. Installation directions are also on this site:
                  http://www.waveeaters.com

                  2) Pump- These skis cavitate in stock form. Cavitation is when the prop spins without hooking up, similar to the tires spinning out on a car. This can occur from an excess of air in the pump. You need to purchase a pump seal kit from Riva to fill in the stock voids in the pump shoe. Those voids create air pockets in the pump causing the cavitation. You also you need to fill in all the voids around the pump with 3m 4200 quick cure sealant to reduce cavitation. Along with better acceleration, you may even notice a slight increase in top end.

                  The Pump Seal Kit can be purchased from Riva here:
                  http://www.rivayamaha.com/RivaStore/...%20Seal%20Kits

                  Directions for installing the pump seal kit and sealing the pump are here:
                  http://www.cajundude.com/pumpshoe.htm

                  If you plan on adding an aftermarket prop, this is a great time to do it since your pump will be removed!

                  3) Catalytic Converters- These skis have catalytic converters in them to lower emissions and they're no good! It's not uncommon for them to fail anywhere from 50 to 100 hours. The 00 to 02 GPRs and XLTs were notorious for this to happen. The 03 and up models weren't as common due to a redesign. When they fail, the catalytic screen will typically break up into pieces and go into the exhaust. RPMs will be reduced at wide open throttle and pieces of your cat will be found in your exhaust. This won't damage your ski when it happens, but 99% of the people who own these skis opt to take the cat out before it fails and put in an R&D D plate and a chip sensor. That'll run you around $90 for both. Putting in a D plate reduces back pressure, decreases the heat, and you may even see a slight increase in bottom end. It will also let you run synthetic oil. With the stock cat in you must run catalytic converter compliant oils.

                  Due to the decrease in back pressure, you will also need to install a temperature sensor bypass to prevent the warning beep from driving you crazy. *note- this doesn't work on the 05 up GPRs. I'm not sure if they need it or not.

                  You can purchase the R&D D plate and temperature sensor here:
                  http://www.rd-performance.com/catalo...TEGORY=Exhaust

                  Directions for removing the Stinger exhaust can be found at this link below. This will take a while to do the first time. A second set of hands comes in extremely handy due to the size of the exhaust. It's very difficult to pull out of the hull. Once the exhaust is out of the hull, remove the bolts at the front of the stinger and the two bolts underneath it holding it together. Your catalytic converter is between the two pieces. Remember to align the tabs before putting it back together.
                  http://www.cajundude.com/stingerremoval.htm

                  4) Hull Inserts- The ride plate, pump shoe, and the rear intake grate bolts screw into hull inserts. BE VERY CAREFUL with these! If you attempt to unscrew one of the bolts they'll often snap the hull insert loose and then you'll have the hull insert freely spinning since they weren't glued properly from the start. From the factory, Yamaha places what looks like a small soda can cylinder on the inside of the hull for the bolts to screw into. To secure these, they just placed a glob of epoxy over them to keep them in place. Since the bolts have loctite on them, the hull insert will often break loose on the inside of the epoxy which causes the entire bolt to just turn with the insert.

                  To take these bolts out, heat them first with a torch and then use an impact wrench. If you don't have one, just make sure you heat them up good first to loosen the loctite on the bolts. A kitchen torch is plenty of heat for these. Just heat them up for about 45 seconds each and then slowly see if they'll unscrew.

                  If you do break a hull insert, it's not the end of the world! It's just the end of your weekend plans! For a GPR you'll need to take out everything behind the battery tray to get to the inserts. An XLT or XLL is much easier since there is a lot of room behind the transom wall. You'll notice the globs of epoxy where the bolts should be. Get a mallet and a chisel and get to work! You'll need to get as much of this up as you can. Once the epoxy is removed, then place a set of vice grips over the hull inserts and then unscrew the bolts from underneath. Since you've gone through all this trouble, DO NOT epoxy the stock hull inserts back in! You can purchase an aftermarket bracket that won't require you to do any extra work to remove the bolts in the future. You can epoxy the new brackets to the hull or use JB weld.

                  You can purchase the brackets here:
                  http://www.rd-performance.com/catalo...s/Girdle%20Kit

                  5) Stock Intake Grate- Whenever you put any aftermarket parts on a GPR, XLT, or XLL you should replace the stock intake grate. Any added top end speed can cause the oem intake grate to be insufficient. What can occur is a high speed, shark, dog leg turn that will throw the rider off at full throttle. This can cause very serious injuries. I recommend an R&D acquavine intake grate to prevent this from happening. It will also improve hook up and handling.

                  You can purchase an intake grate here:
                  http://www.rd-performance.com/catalo...Scoop%20Grates


                  Here are some handy links for your journeys:

                  Service manuals for your skis can be found here:
                  http://greenhulk.net/forums/showthread.php?t=9546

                  CajunDude's "Do it yourself" instructions for many typical repairs:
                  http://www.cajundude.com/techpagehome.htm

                  Atlantic Jet Sports- This is a great company located right here in NJ that usually has everything in stock at great prices.
                  http://www.atlanticjetsports.com/

                  Island Racing- Carl is one of the forefathers that developed a lot of the technology and information out there for GPRs and XLTs. He is always more than willing to help you out on the phone and knows a LOT about aftermarket performance parts and the affects to the ski. His prices are also extremely good and his customer support is the best. He comes highly recommended from me. His prop work is also top notch.
                  http://www.islandracing.net
                  2012 Yamaha 242 Limited S
                  97 Monterey Montura 186 3.0L Volvo Penta SX (sold)

                  Comment



                  • #10
                    Re: yamaha 1200 engine failure

                    Can someone tell me with certainty if I need to re-jet the carbs on my 1999 1200XL limited w/powervalves when replacing the cat con with d-plate and chip? I can't stand the idea of having to go into the bank of carbs again and doing some trial and error horse****. One of the internet stores that sell the d-plate kit say that you may have to do this but offer no other information. I am also wondering why if "everyone" replaces the cat con with the d-plate why there are absolutely NO used cat cons for the waverunner on ebay. Something don't smell right here...need an honest assessment please.

                    Comment



                    • #11
                      Re: yamaha 1200 engine failure

                      No you do not need to rejet. If you need a cat con let me know. I might have one in my basement laying around if I didn't chuck it.

                      There are none for sale on ebay probably for two reasons... #1 nobody wants to buy one since if you're going to spend money you might as well get a D plate and chip and #2 the newer models don't use them.
                      2012 Yamaha 242 Limited S
                      97 Monterey Montura 186 3.0L Volvo Penta SX (sold)

                      Comment



                      • #12
                        Re: yamaha 1200 engine failure

                        skysurfer, thanks for your quick reply. If you get a chance can you check to see if you have one for the 1999 1200xl limited waverunner. I haven't removed the stinger yet to check if the cat con is bad but I suspect it is. The exhaust indicator is beeping to beat the band and the ski only gets up to 36mph at WOT. I just got back from hitting some big waves in Panama City Beach and suspect I finished off the combs...thx again!

                        Comment



                        • #13
                          Re: yamaha 1200 engine failure

                          I just checked and I must have either thrown it out or given it away. There are a lot of popular pwc forums you should check out (if you're unaware PM me) and that engine was used in the XL1200 limited, XLT1200, and the GP1200R. You can also use the cat from the GP800r and the GP1300R as well. In fact, the later cats were slightly better and more reliable than the older ones so if you can find one from a GP1300R you'll be in slightly better shape. My point... you should be able to easily find someone willing to ship it out to you for probably just the price of shipping. If not free, probably really cheap since nobody wants them.

                          My question... do you realize how much of a PITA it is to remove the stinger? And you do realize the newer cat will most likely fail again? Why not just spend the extra money and put in the D plate? After you realize how much work it is to take the stinger out (get's easier, but it's still not fun at all) you might regret not spending the extra cash. Plus it's better for the engine since it allows it to breath easier.
                          2012 Yamaha 242 Limited S
                          97 Monterey Montura 186 3.0L Volvo Penta SX (sold)

                          Comment



                          • #14
                            Re: yamaha 1200 engine failure

                            skysurfer, you make alot of sense. I took out the stinger a couple months ago to get to the carb banks and you are right,,,big PITA!! I just hope to goodness I don't have to re-jet anything taking out the cat con. check out what Riva says about it on their website in the link below...

                            http://www.rivayamaha.com/RivaStore/...al%20D%20Plate

                            "NOTE: Installation requires additional fuel be supplied to motor to prevent lean conditions. Carbureted models may require replacing jets"

                            My question is replacing jets with which ones? No additional information. Why do they say this?

                            Thx....

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                            • #15
                              Sign up today
                              Re: yamaha 1200 engine failure

                              I know of many people who ran without doing a rejet for carbed models or adding an EFI for the fuel injected models. On my 1300 (fuel injected) I already had an EFI due to other mods while on my XLT1200 (carbed.... samed engine as your XLL) I only had the D plate as far as engine mods done. The XLT ran perfectly fine without a rejet.

                              If you want an expert's opinion feel free to give Carl at Island Racing a call. You can google his shop for his number or PM me. He taught me a lot back from 2000 on and he's an amazing guy. He's always willing to talk to someone on the phone about a technical question. His prices are great, too... but his customer service is what makes him stand apart from the rest.

                              I'm no expert and am just going by my experiences (been dealing with those engines since 03) and what I've seen from others as well. So by all means contact a pro for their advice. If it were me, I wouldn't do a rejet.
                              2012 Yamaha 242 Limited S
                              97 Monterey Montura 186 3.0L Volvo Penta SX (sold)

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