300/440/550 New to me js550

[Crossman16]

New to the forum and gaining a lot of new knowledge. I recently inherited a 1989 js 550 that has been sitting since 1995. Any advice on getting the jet ski going again? Today I cleaned out the fuel tank and all fuel lines along with the fuel filter. Today I picked up new spark plugs and a new battery. I found an owners manual online and will run through that. Just looking for any advice from the experts. Are there any good websites to order new parts from? I would like to get a new air filter and maybe a new carburetor. Any recommendations? Thanks!

 

[OldSkoot]

MY newbieness says to run some Seafoam through that carb unless you are rebuilding it. Other than that, i'd say grease your fittings, check your impeller clearance, borrow or buy a compression tester and for peace of mind (as well as future wrenching) see where the current compresson is BEFORE hitting the water, And little things i'd check would be..... only put enough fuel in the tank to run on reserve and see if the reserve is working, then fill up and switch the selector and check it, Lube your throttle and steering lines/linkages, run the ski with the hood off and see if you have ANY hint of a exhaust leak(they will strand you on the water if you do). That'd be my checklist.

 

[fastgtfairlane]

if you decide to replace the carb, get a mikuni sbn 44, it is a much more reliable carb than the bn 44 that is on it now... the sbn is a direct fit and can be tuned should you change the pipe, compression etc... doing all of what you listed should get the ski running again... if you get it running and take it to the water and it wont run right as in no power when you put it in the water then you probably need crank seals


good luck with your new ski, you will have lots of fun! post some pics of it! also there is more of a vintage ski following on pwctoday.com for future reference

 

[hillbilly550]

To bring a sleeping ski back to life.
Spray some fogging oil on the pistons though the spark plug holes
Remove all old fuel from gas tank and replace with new.
Install a new or fresh charged battery.
While you have the battery and spark plugs out roll the crankshaft over to feel any drag. If it dosent roll over Easy then there are other issues that need addressed.
Check the impeller for damage, with a flashlight through the intake grate and through the rear outlet you can see the prop. You are looking for bent and damaged blades on the edges of the prop. Often times the impeller is worn out and it makes them ride like a turd (not just because they are a 550)
install the new spark plugs in the wire boots and rest them against the head to ground them out. Crank it over and look for spark on both plugs if there is spark you are close
If you can, use a compression tester to check your cylinder compression. They should read around 130-140 psi if i remember correctly. If it is less than 110psi you are beating a dead horse. The compression between cylinders should be even (within 5 psi is acceptable)
At this point install the battery and plugs. I pour some premix (an ounce or so) down the carb to prime it and crank it over. see what happens. If it doesn't fire I usually add more fuel. You may start to see some smoke come from the exhaust and that's a good thing.
You need fuel, air (compressed) and spark to make an engine run. If you are missing 1 it doesnt work.
Once you get it running in the garage you need to hook it up to a water source to keep it cool.
If you get it running on it's own I like to put it on the ramp still strapped to the trailer to load test and check for leaks with the hood off.

Good luck. Don't buy any parts for it until you can at least verify good compression and spark.

If you need parts I do have some, you can pm me. I have some nice sbn carbs, good cranks and some performance items.
There is a local MX shop here that has a ton of parts for the vintage skis too.

Have a nice night

 

[Crossman16]

Thank you for all the great information! Hopefully I will get a chance to work on the ski this weekend. I would like to get a new carb and air filter. The air filter on the ski now doesn't seem right. It is like a hard foam. Is that usual? I will be checking out the other forum mentioned. Thanks again!

 

[hillbilly550]

Thank you for all the great information! Hopefully I will get a chance to work on the ski this weekend. I would like to get a new carb and air filter. The air filter on the ski now doesn't seem right. It is like a hard foam. Is that usual? I will be checking out the other forum mentioned. Thanks again!

thats the factory style flame arrestor...... check compression and spark before buying any parts.

 

[_evan]

I would take the carb apart spray everything down with carb cleaner re assemble and run fresh gas.

 

[Quinc]

To bring a sleeping ski back to life.
Spray some fogging oil on the pistons though the spark plug holes
Remove all old fuel from gas tank and replace with new.
Install a new or fresh charged battery.
While you have the battery and spark plugs out roll the crankshaft over to feel any drag. If it dosent roll over Easy then there are other issues that need addressed.
Check the impeller for damage, with a flashlight through the intake grate and through the rear outlet you can see the prop. You are looking for bent and damaged blades on the edges of the prop. Often times the impeller is worn out and it makes them ride like a turd (not just because they are a 550)
install the new spark plugs in the wire boots and rest them against the head to ground them out. Crank it over and look for spark on both plugs if there is spark you are close
If you can, use a compression tester to check your cylinder compression. They should read around 130-140 psi if i remember correctly. If it is less than 110psi you are beating a dead horse. The compression between cylinders should be even (within 5 psi is acceptable)
At this point install the battery and plugs. I pour some premix (an ounce or so) down the carb to prime it and crank it over. see what happens. If it doesn't fire I usually add more fuel. You may start to see some smoke come from the exhaust and that's a good thing.
You need fuel, air (compressed) and spark to make an engine run. If you are missing 1 it doesnt work.
Once you get it running in the garage you need to hook it up to a water source to keep it cool.
If you get it running on it's own I like to put it on the ramp still strapped to the trailer to load test and check for leaks with the hood off.

Good luck. Don't buy any parts for it until you can at least verify good compression and spark.

If you need parts I do have some, you can pm me. I have some nice sbn carbs, good cranks and some performance items.
There is a local MX shop here that has a ton of parts for the vintage skis too.

Have a nice night

How do you roll the crank over by hand? Do you just turn the prop or can you do it from inside the engine bay?

 

[danimal365]

you should be able to turn it over by hand from the engine bay... there is a plastic cover over the driveshaft couplers on the back of the engine. make sure the plugs are out... it will make it much easier

 

[burton148]

Grab the coupler that is on the back of the engine to the firewall/ bulkhead.