How do I know if I need a new engine?

[tommy1976]

I'm new to this board and jet driven boats in general so hopefully I don't offend anyone.

I just aquired a Seadoo challenger 1800 with twin 787/800 engines and previous owner said "both engines need replacing" - although he didn't know why or specifics of it.

So far I've determined that the right engine starts but runs very roughly (sputters, misfires, can't get RPM up) and the left engine is completely locked.

Wondering if I can get some suggestions for:

Left Engine
- will be checking compression tomorow - asides from compression what are indicators if an engine requires replacement? What additional tests can be done before removing the engine?

Right Engine
- I understand that lock-up can come from a variety of things (bad starter, hydrlic loc, seized jet drive, etc.). How do i diagnose it to be a locked engine before actually removing this?


Can someone give me some idea how many hours it will take for an average person to remove the engine from a Challenger 1800? Trying to gaguge if this is a job I should start myself or get some help with.

Many thanks!!

 

[timmyboy76]

xcellent boat, tommy.....work'n on one, right now, that been submerged in salts, for last 2-months...pulled plugs, shot everything out, pulled carbs, went thru them(especially the xcellerator pump on each pto carb), dowsed entire bottom end in 2-stroke oil..etc, only because, owner felt, if there gonna go, might as well, use them til they do.

Your situation, the left motor not throttling/backfiring, more likely do to bad plugs, fuel and carbs need gone thru, and the brass fitting protruding into carbs, are for the xcellerator pump. If you think you can do the job, then it shows you aint intimidated by it, and therefore, can do the job..just a little time.

Other motr, go ahead and undo the cables at the pumps and the 4-17mm nuts at the seized motor side, and pull that pump off, only take 10min, then see if the motor then is stuck..(remove grey shield from motor, and turn pto), if no turn, then get some trans oil or pb-blaster and let soak into cylinders for a day or 2, then afterward, put pipe wrench on pto and turn/rock, see if it breaks loose, if not, pull the head off.

A motor, on good day, undo everything, and should be about 1-2 hrs tops, since you got all the room in da world in there, and besides, need to pull jet-pump/driveshaft anyway, to make easier.

So, give those few ideas a shot, then halla back.