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  1. #1

    raider 1100 cuts out at top speed

    So today me and my brother decided to go out into tampa bay, leaving the river i went full throttle for a fairly short period of time and no issues, got out into the bay and it was very one point we stopped at an island to take a break, talked about how great my $400 ski has been running etc etc...karma came around and slapped me in the face, went to leave the power nothing just dead...
    tinkered around with things trying to figure out what the hell just happened while battling the waves, i pulled the fuse plug out and the fuse shot out into the hull(which had some water in it)...found it dried it off reinsert, fired right up..whew!!!...

    fast forward about 15 mins we make it back to the river to hit up the bar on the river, as soon as we get past the idle area i go for a top speed run since i have a new prop/grate and as soon as i started getting it wide opened it lost power like i let off the i did and "burped" the throttle a few times still running and ran fine low to mid range but went WOT again same thing but stalled this time and took a good minute to get back started....went to the bar after getting it started, checked the fuse again and it was coming out just a smidge so tightened it back up, went back out same problem...seems to run fine every where else except WOT...ONE time it did die while cruising the same way but fired right back up and cruised back to the dock no other issues.

    since last time i took it out where i did multiple WOT runs all i have changed is the prop and the intake grate, everything else is the same...

    so what could be causing this issue?...i thought possibly CDI? but not really sure how to check it..fuel shouldn't be a problem, carbs have been rebuilt and been out since being rebuilt as well as the primer kit install

    basic list of stuff done is

    primer kit
    choke removed
    carb's rebuilt

    everything else isn't motor related?

    pro tec grate
    cut ride plate(shimmed 3 washers)
    5 degree nozzle
    solas i 13/19 prop
    disconnected visibility spout

    any help would be appreciated thanks!!!

  2. #2
    checked compression 90psi across the board, going to try to examine but i think lean seizure is what happened...need to find the cause though, been running great til now..

  3. #3
    90 across the board seems like a big coincidence. If you seized a piston you should still have decent compression in the other jugs. Try another gauge.

  4. #4
    thats what my pwc mechanic told me, but i tried the gauge on my boat and the compression was right on par, i guess it cant hurt to check with another gauge, but another thing i noticed when i went to restart it felt "sluggish" to turn over almost like a dead battery, after trying for a few moments, it would eventually fire up and ride again fine until WOT when it would do it again.

    btw my yamaha is an 86 115 v4 and is 120-123 which seems where it should be, and ive used this gauge when i bought the ski and it was 120 across the board..but like said ill borrow someones and give it a shot. thanks!

  5. #5
    Ok did some testing today, i tried fattening up the highs a bit to see if that helped, well i went out on my lake which is pretty small but enough to get a wot run for a second or two, i did probably 10-15 runs before it started acting up.. on the 3rd to last run at the end it started loosing power , like i could just feel it dwindle away...last run it started the same way but came on sooner.. The pisser is moving a nice stream so the cooling system is working..something maybe worth mentioning before i noticed this issue the day we went out, we stopped at a island and my kill switch didn't cut off right away so i was on sand for a few seconds...idk if this has something to do with it or something i need to look at, the prop and everything looked fine after riding so i dont think any issues there, but maybe if the cooling sucked some sand up??? idk i dont know that much about them so any help is appreciated, and i double checked compression with MY gauge because i haven't found a 2nd one and i was mistaken a bit, its actually 100 across the board not 90, gauge goes from 90 to 120 spoken then the dashes in between are obviously 100-110 and i didnt look close enough to realize it was actually 100...still looking for another gauge.. Thanks guys.

  6. #6
    This is tough one. Intermittent problems are the worst, its almost better if it just failed and you could troubleshoot it. lol. There's a lot of possibilities here. I wouldn't assume your cooling is ok because of the water stream out the pisser though. Its possible that you have some sand in your cylinder water jacket. Once in there, it sinks to the bottom and the water can pass over the top of it. After some WOT runs your cylinders heat up and you start to lose compression from thermal expansion. I would try feeling the motor after some hard riding. Make sure its not so hot that you cant touch it. It would probably be a good idea to check out the plugs too.

  7. #7
    thanks man and def good point, something else i noticed today when tinkering...first start it came right on, on the trailer, shut it off, lifted hood turned idle up a bit and dropped hood again , went to start...nothing no power at all...i checked fuse good(it came out one time riding yesterday) i followed the power wire to the starter i believe moved it a bit to see if it was connected (couldn't really see it just wanted to feel around)...disconnected the black/white wire to see if that allowed it to start, i could here a single click when i hit the start button but nothing else...plugged the black/white back together..still single click...wiggled the power wire at starter again...then started turning over....idk if a relay is a issue or the starter it self?? could this cause the power loss if it is a problem?? or something electrical...

    and i def agree intermittent problems are the worse, i had one on my old lexus sc300 that took a year to figure out....this stuff is irritating for sure and me not knowing much at all makes it even worse trying to figure out different things that it could possibly be..then how to test them haha

  8. #8
    Once you're ski is fired up, the starting circuit is out of the equation. The only thing you should make sure of is that you have a good solid ground connection. A bad ground can cause all sorts of issues.

  9. #9
    ok then thats out, next thing, i started going through the cooling since i pretty much beached my ski and i think i figured it out, now i cleared the hole system almost and found nothing...however one hose it kind of loops out and back into the exhaust RIGHT before the rubber exhaust hose...i pulled this and seashells came out...hose was almost entirely i took the hose connected it to the nipple above the rubber hose and put air to it and it blows the hose off, so im guessing its really clogged, the other side i blew air through and air came out but nothing else...seemed cleaned..

    so this nipple , whats it do and how can i unclog it???

    seems like i could have a heat issue which is causing a heat seizure which would explain lower compression in all cylinders?

  10. #10
    Makes total sense now. You have no water going to your waterbox, which will result in loss of power on top. If it were me I would take the pipe apart and make sure everything is cleared out of there. There's some pretty small passages in there and it will be difficult to clear them without taking it apart. You'll have to replace some gaskets, 4 total if I remember right. I know where you can get them pretty cheap though.

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