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masonf24

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I have practically two new motors from sbt put into my boat recently. i bypassed the oil pump so i am premixing now. the boat runs great until i get to 30mph then the back right engine shuts off and won't start. still haven't been able to start it since. compression is fine on all cylinder 148psi. it is a 97 challenger 1800. really need help soon. thanks for any advice. i am thinking it is the carbs but don't want to spend the time to rebuild if its something else. and my gauges have stopped working but that was before this happened. thanks:cheers:
 
I would definatley open the carbs and rebuild if necessary. A must do after replacing engines. Did you determine what caused the first set of engines to go and fix that problem before risking damange to new?
 
yea the oil pump quit working so that is the reason the engine messed up so now they are being bypassed. Well i would say i will try tomorrow the cup in the cylinders trick but does it need to be premix?? and if it does fire up then what does this mean? thanks:cheers:
 
These 2 strokes are pretty simple, all the need to run is fuel, spark and compression. You mentioned it has correct compression, so make sure it has spark by removing a plug and hold it to a metal part of the block and while cranking see if you can see a good spark on the plug. Then put a spoon full of gas in the plug holes, replace plugs and see if it will try to start. If it does but soon stops it must not be getting fuel from the carbs. This little bit of primer gas makes no difference if it premix or straight gas.

NOTE: I would not mess with cooling water unless you get it running for more than 15 seconds or so as you will risk flooding the engine with water if it stops running.

However based on your description of it suddenly quit running I suspect something electrical, like no spark.

I would be interrested to know more about why the oil pump quit working as it is very rare they break. Oil pumps are often the blame for engine failure when in reality the cause is a plugged up fuel system causing a lean fuel/air mix which burns hot enough to destroy the pistons.
 
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I am positive the oil pump is wrong because i personally took apart the oil pump to find the pump shafts teeth were shattered. So the oil pump just quit pumping. i didn't want to risk this again so i bypassed them. i have replaced the mpem, stator, and both motors. all has been installed by a dealership. just a little background for you on this boat:ack: this has been hell and a lot of money so i am hoping for a quick fix. just let me get this staight i add fuel into the cylinders and if it dies then the carbs aren't delivering fuel to the engine but what does it mean if it keeps running? thanks you guys always come through:)
 
you can pull the return line, saee if gas in there, but more likely, dump a cup of gas in, just to see if it fires up. If it does, then dies, at least, you know its fuel system related. If it dont fire, then like seadoodude mention, a spark/electrical thing.
If when gas is dumped, and it stays run'n, then sounds like, ur good to go. Check the inline filter for debris...etc Just try'n to speculate a "reason" for it to shut off on you, and now wont fire up.:cheers:
 
another thing is that when i winterized it all i did was run antifreeze through that engine that is messing up now. i know i did the process right but are there certain steps i need to do to dewinterize the boat??? the other motor was just in my computer room so i didn't have to winterize that one lol.
 
another thing i am asking these questions for my friend that i sold the boat to. he said got it started and took it out today and about the same thing happened. the motor died and wouldn't start back. except this time the engine won't even turn over now. he says he hears a clicking noise but the engine won't turn over. i told him to try it with the spark plugs out and it still won't turn over. no clue what this could mean. just let me know what you guys think. thanks!!!!!!!
 
ok went to look at it today and used a pipe wrench to try and spin the shaft. i could almost spin it half a turn the it locks up and go back the other way a half a turn and then it locks up. it is VERY hard to turn. just seeing what you guys think could cause this and i told him to just remove it and we are sending it back to SBT because i still have the warranty on it. let me know some things to look for that might cause this since i want to get it giong for him. the oil tank is full and no hoses are pinched. he premixed with the oil pumps blocked off. i am think somehow the oil did not get to the bottom end of the engine which caused it to lock up but by no means am i pretending to know how to fix this. thanks for any wisdom!!!!!:cheers:
 
you try'n to spin it with plugs in?...try'n to understand. All you did was winterize it, then now, it wont fire, but you have 148psi in all 4 cylinders, right.
 
actually this is the rebuilt one from sbt that didn't get winterized because it was in my computer room. installed professionally and third time out it seized up. yes the plugs were out just kinda confused on how this could happen so fast. i already started the claim warranty process through sbt and the engine should be out today. just trying to find some ideas so this won't happen again. thanks.
 
ok, i get it....go thru thre carbs, again, make sure RV was set correctly, double-check, that you didnt "pinch" the oil lines that lead to the RV assy, think'n it wuz the "injection" lines...

Think, "pwcdoc" gonna jump on this thread/post.....:rofl:
 
lol....where do I even begin?

Let me begin by saying any motor installed without finding the root cause of the initial failure was not professionally installed.

When you say "bypassed the oil pumps", what did you do to bypass them?
 
Yeks...this is a nightmare! If the "professionally" installed engine is the problem, let the installer look at it to determine what he messed up. It sounds like you might need to have some one give both engines a good look over. It is almost impossible to give you advise without looking over the engines first hand. Too many people have been doing too many different things, with no idea what the heck they were doing, it sounds like.

My advise is to have someone look over the engines that have real seadoo experience with the engines. Start from the basics and go forward.

Karl
 
i agree but when i removed the engine to get it ready to ship to sbt i found the oil shaft inside the oil pump was shattered and then the results came back form SBT confirming that the engine wasn't getting any oil. so i thought to resolve this problem i should by the oil pump block off kits, which i did and i did this to both engines so i could just run premix. the other engine is still running fine. i just bought a new oil shaft again so this time i am hooking the oil pumps back up so for the first tank it is going to get way too much oiil coming from the gas tank and then the oil reservoir. i will make sure this time no hoses are pinched is there anything else i could look for?? is there anyway the impellor can lock?? what happens if the wear rings wear out??? i don't even know if my boat has these. thanks for any help
 
the beginning of the last post is the first time i removed the engine not this time..thought i should clearify that.
 
If the wear rings wear out the rps will go high and the impeller will have cavitation. The impeller shaft could lock up if the impeller looses a bearing, but I have never see it just lock up tight before. Usually it will get noisy and indicate it is going bad because the impeller is always turning it won't just Lock up fast.

Karl
 
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