Seadoo RX DI Strange problem

[kashov]

HI Guys I recently bought Jetski Seadoo RX DI, me and friends of main have been having a lot of fun for past few months. Most of the time we were pulling us on a wakeboard. One day I forgot to check the oil and while we was riding the jetski suddenly stopped...ok the oil tank was empty and we went out of the water (by telescopic paddle, I wear such a think because we ride on big a river).... got the jetski back home.Bought the oil on the next day and filled it into the oil tank then tried to start it ....it started without any problem.. everything was fine and we rode it few weeks.

Few weeks after that when I was riding the jetski, it started to lose a power then I immediately switched it off...but when I tried to start it again , it did not start. Went out of the water again and tried to start it for sereral hours but without any luck. What I understood here from the guys with the same jetski most of the problems on this engine are cased by the fuel pump but that is only what I saw here in the forum.

What we made today while were trying to fix it was: We screwed out the spark plugs and test them one by one if they made a spark, the result was that they made a very good spark..ok probably that was not the problem. Next thing we made was to check the fuel filter if the fuel is able to went through it ...the filter was ok (or I think so because I was able to blow through it.. ). Then we test the fuel pump if it worked ...ok it worked and pumped a fuel. I don't know if that pressure was enough to work well ,probably I have to find a way to measure it...

The strange thing was that the engine started 2-3 times today while we were trying to start it but when we released the accelerator the jetski switched off immediately I mean there were idle rpm's it just stopped. I think it looks like there is not enough fuel pressure to the injection which cause no fuel injected but I am not sure because I am not able to measure the pressure also there are bunch of things in this engine which might be broken...

I will be very thankful for any advice ....

P.S. I forgot to mention that I suspect the lanyard cap, sometimes I had to push it hard to start the engine otherwise it did not start, but that was rarely.

Thanks
Pavel

 

[adamsbj123]

Before you go any farther you should do a compression test. Ideally both cylinders will have around 150 psi. You may have scored the pistons when you ran out of oil. I wouldn't troubleshoot anything unless I know there is good compression.

 

[kashov]

I will do that tomorrow but is it possible as I have rode it without any problem for a month since then?

Thanks

 

[adamsbj123]

Stranger things have happened. Considering you have good spark at the plugs that eliminates alot of things electrically. You may well have a fuel delivery problem but like I said earlier I personally would not troubleshoot any further unless I know the compression is good.

 

[kashov]

OK I just tested the cylinders and think I found the problem. First cylinder has about 140 psi but the second has just 26 psi. Tomorrow we are going to open the head to see what was happened , I can take pictures if it is interesting for somebody.... But I can't understand what is the reason for that, because we have been riding the jestksi almost a month since we ran out of oil without any problems.

 

[Spimothy Leary]

OK I just tested the cylinders and think I found the problem. First cylinder has about 140 psi but the second has just 26 psi. Tomorrow we are going to open the head to see what was happened , I can take pictures if it is interesting for somebody.... But I can't understand what is the reason for that, because we have been riding the jestksi almost a month since we ran out of oil without any problems.

i think this statement is incorrect.... barring sheer coincidence, i'm guessing that running it out of oil might be the reason you have 26 psi. so.. yes,,, there were problems, you just weren't aware of them

 

[kashov]

HI Guys, let's see some pictures of my opened jetsky engine... to see what was happened...you won't believe what small thing caused that to happen but the problem is not because I have ran out of oil the a month ago...

 

[adamsbj123]

The top of the piston looks OK so I would rule out detonation/lean run. The piston skirt is badly scored. This is typical of overheating and lack of lubrication. Why do you think running out of oil is not the cause of this damage? Have you taken a good look at the other piston and the bottom end? Just curious are you planning on a new top end or complete rebuild?

 

[kashov]

Yes , I just ordered complete rebuild kit.. We found the reason for this problem by chance, as we play with the acceleration cable to see how is it works we found out that there was a cable for the oil pump too, so once you press the acceleration, the oil pump cable works as well and what we saw is that it had broken end of the oil pump cable which had to connect the end of cable to the pump and pull it which movement should inject oil in the engine but in that case as ever you accelerate the pump only inject oil for idle RPM's even on maximum RPM's!. So that small thing cost me rebuilding.. but however we will do it our self the engine is very sample compared to some 4 stroke engine.....

Thanks for the help!

 

[Dennis]

That damage appears to be from lack of lubrication. Whether it happened a month ago or a week ago doesn't really matter. :cheers:

 

[Tsef]

A seadoo oil pump when cable is not hooked to pump is made to default to wide open as to over oil the ski to not cause engine failure. Face it, it ran out of oil. Pump was not at fault because of broken cable pump actually used more oil by not being connected by cable.

 

[kashov]

hmm....you might be really right...