300/440/550 550 has me stumped

[lake-skater15]

I've got a built 550 and lately it's been having a weird issue I can't quite figure out. It will start up and run great but if it dies it won't start up and when I crank it over a little bit of smoke comes out of the carb. When it starts doing that it has spark and fuel but for whatever reason it won't start and then if I leave it alone for a while it will start up and run. I can start it up a few times without any issues but after a few times it will quit wanting to start. Help!

 

[lake-skater15]

Bump. It's been doing this the last couple rides and I can't figure it out.

 

[D-Roc]

piston port or reed motor? if it is a reed motor and difficult to start when warmed up it could be the reeds. if it is a piston port, well they are slow starters and need a good strong battery and starter motor with good wires to crank the motor fast. it usually takes a few more revolutions to fire the piston port vs the reed motor. piston port also seem to flood easilly when turning over slow due to battery, starter or wires creating too much resistance. all 550 are old so these parts are usually at the end of their life and need replacing.

 

[lake-skater15]

It's a piston port motor.

 

[D-Roc]

this is the exact same thing this one 550 did that a guy i knew had. on the first few starts, no problem, he would fall off alot and then he woulld be on the starter forever and the battery would get weaker and never start. It was flooding itsellf. we put on a sbn carb, cleaned the starter, different stator, different rectifier, leak down tested and it would still do it. i suspected a bad starter and wires to it because the battery would drain so fast. fully charged batter it would start. after 15 min of falling in and stalling it, we had to pull it out of the water so it would spin fast enough to start up. how is your battery and starting system?

 

[N2 H2O]

might be crank seals. if they're bad, the engine starts fine cold, but is hard to start once it warms up.

 

[D-Roc]

this is true.

 

[lake-skater15]

Ok so try changing the wires and check the crank seals?

 

[D-Roc]

a little ether around the seals while idling will let you know if they are sucking in air. the piston ports seem to need to spin fast to fire up, in the water with a poor battery, with old wires that are coroding from age, and poor grounds and an old crusty starter and leaky seals will for sure make it hard to start. haha. let me know what you find out because to this day that ol 550 haunts me as the one i never fixed.

 

[lake-skater15]

To me the 550s aren't so bad. Parts are cheap and if you take care of them they are as reliable as any other kind of ski. I did however just finally get my first x2 and first superjet.

 

[Polish jet pilot]

Sorry to come with bad news but in my opinion your engine is done. You will need a top end rebuild + new crank seals. I had exactly same symptoms on my PP. I,s the issue of compression. If smkoe goes up the carb that means no compression. It will start fine without load but in water no chance...

 

[Polish jet pilot]

The good side is that tope end kits are cheap.

 

[Ĥölënböt]

Sorry to come with bad news but in my opinion your engine is done. You will need a top end rebuild + new crank seals. I had exactly same symptoms on my PP. I,s the issue of compression. If smkoe goes up the carb that means no compression. It will start fine without load but in water no chance...

i agree exactly the same experiance i had with a friends ski
go for the rebuild its worth it

the only other thing it could be is bad porting but im guessing rebuild is in order

 

[2XLR8]

don't skimp out on the bore job. Get the reed motor pistons because they have 2 rings and seal better.

 

[lake-skater15]

But it has 180 psi compression in both holes. I thought the same thing at first but I tested compression and it's great.

 

[D-Roc]

yeah don't waste money on a topend. that isn't the problem. check your battery, wires, and starter.

 

[lake-skater15]

Alright I'll check the wires and crank seals and check compression again just to make sure.

 

[XJCrawler]

Send you coil to Jet Ski Solutions and you wont have problems with your coil wires anymore, they are so much beefier!

 

[Polish jet pilot]

Take the top end off - its a 30 min job. You will then know the REAL truth....

 

[lake-skater15]

No leak in the crank seals but upon another test of compression I found that it's 210psi in the rear cylinder and 180 in the front. I'm taking the top end off as we speak but I have a feeling it's a head gasket.