Uggghhhh...do i need a new motor? please help

[blauther]

I bought this ski running very poorly...
i cleaned out the carbs and adjusted them, making sure that i didn't run into a lean condition.
(if anything...it may have been running slightly rich at low speeds or idle)

The ski was used for about 3 days without any issues (occasional bog while trying to accelerate after idling for 20min)

4th day...someone other than me was using the ski...broke down and came in with SeaTow(best $125 bucks ever spent)

Here is the story:
-first they ran out of gas
-seatow brought 5gallons out to them
-Ski started and they got to gas station and filled up
-Ski stopped again after running for a while
-from what they described...motor seized up ...they said that they hit starter, but acted as though it was a dead battery.
-Seatow brought ski back to the dock


I looked at ski when i got it home...it would crank but wouldnt run...i pulled the plugs and they were very wet
I pulled the fuel filter and found dirt in the bottom and the mesh insert had come free from its mount allowing dirt to be able to get to the carbs.

left both plugs out and cranked motor...seemed as though mag carb was dumping fuel into motor

I turned fuel valve off and eventually got the motor to fire (i think this happened once the carbs stopped dumping fuel into motor)

Checked compression for the heck of it (i had never checked compression on this machine before)
got 100 on the pto cylinder
got 135 on mag cylinder

NOW WHAT...that seems pretty bad...not sure if this is always what the compression was...ski did about 40mph after the carbs were cleaned out.

I can clean the carbs again, but what do i do about the compression? I am scared that i need a motor.

Any help would be greatly appreciated...you guys have been great so far.




95 Seadoo explorer
2 stroke
Dual carbs
657


Lou...i didnt stay in a Holiday Inn Express last night...thats why i need your help

 

[RutlandRacing]

That compression isnt bad, i run one of my skis with 100 125.

 

[blauther]

That compression isnt bad, i run one of my skis with 100 125.

Thats good to know...i was getting really worried...i kept reading about compression tests in the 150psi range

 

[RutlandRacing]

150.. yeah lol a new engine... but yea the more compressesion the more power.. it will still go 40.

 

[CReynoldsMIZ]

engines where they compression is more than 10% are going to need a rebuild eventually. You can keep running it like this, but eventually you are going to have a problem down the road. If it was me i would take of cylinders, hone them out, put a new set of rings on and hopefully this will get you by for a few years.

 

[El Toro 33809]

The compression really should be higher than what yours reads. Do you have access to a different gauge? Sometimes the gauges will show different readings.

You could pull the cylinders and see what the ring gap is. If new rings would help, you might be good for a while longer. If it needs more than rings, it may be best to replace the engine. It wouldn't be any fun to redo the top end, only to have a tired crank go out on you.

 

[blauther]

The compression really should be higher than what yours reads. Do you have access to a different gauge? Sometimes the gauges will show different readings.

You could pull the cylinders and see what the ring gap is. If new rings would help, you might be good for a while longer. If it needs more than rings, it may be best to replace the engine. It wouldn't be any fun to redo the top end, only to have a tired crank go out on you.

I am going to try to get a hold of a different guage from a buddy of mine, but i am pretty sure this guage is accurate to within 5-7lbs.

If i pull the cylinders...do i need to purchase a gasket set? where would i find the spec for the rings?

Thank you for your help

 

[blauther]

OK...i have a new piece of information that doesn't make me happy...

While i was poking around when i got home from work today...

I found that the cable that actuates the oiler had come out of the keeper. Essentially the motor was not getting oil.

how resilient are these motors after they have been seized?

if i can get it to run, is there a chance that it will be ok?

I think i feel sick to my stomach

 

[El Toro 33809]

My understanding is that if the cable on the oiler isn't connected it goes to full on. It would not be lacking oil. Do you remember if it was still smoking?

With the compression you are dealing with, it needs attention even if it didn't seize. Pull the heads and see if the cylinders are scored.

 

[Rotor13B]

OK...i have a new piece of information that doesn't make me happy...

While i was poking around when i got home from work today...

I found that the cable that actuates the oiler had come out of the keeper. Essentially the motor was not getting oil.

how resilient are these motors after they have been seized?

if i can get it to run, is there a chance that it will be ok?

I think i feel sick to my stomach

Hmm...

The oil pump should default to wide open in event of a cable failure. If anything it's getting too much oil at idle, This could possibly explain the bog you described after stints of long idling. If it were me I would recheck compression with a different gauge. If that jives with what you got earlier i would gap and replace the spark plugs with some new ones. You probably should pull the oil pump and make sure that is working properly for piece of mind. Check the oil lines for oil and make sure it doesn't have air bubbles in it preventing oil from traveling to the motor. Like what was said earlier a hone and re-ring might buy you a couple more years but if the motor has never been rebuilt you're probably on borrowed time.

 

[LouDoo]

Sorry I didn't see this post until this morning, last night I was working on my ski. I think that El Toro hit the mark in post no. 9.

Compression of 100 and 135 is simply not acceptable, 135 is marginal but 100 is not acceptable. We need to find out why the compression is so low, and not only is it low but it's more than 10% difference than the other cylinder, this troubles me because even if the gauge is off there's still going to be more than 10%. I think it's time to pull the head and have a look.

The oil pump shouldn't be a problem, the pump is designed to go full open in case of a cable failure.

I did see that Sea Tow pulled your boat back to the dock, did anyone think to pinch of the water supply line from the pump to the motor. If not you could have water in the motor, this is another reason to pull the head.

Lou

 

[blauther]

The oil pump shouldn't be a problem, the pump is designed to go full open in case of a cable failure.

I hope this is the case...i wasn't on the boat, so i don't know if it was smoking or not...the cable was still attached but the end came out of its retainer, so it was still partially held by the cable...hopfully it had enough play to swing clockwise into a full open position.

I did see that Sea Tow pulled your boat back to the dock, did anyone think to pinch off the water supply line from the pump to the motor. If not you could have water in the motor, this is another reason to pull the head.

Lou

I am positive that no one pinched the water supply hose...this would make sense...when i pulled the plugs, both plugs were wet, but i did notice that the front plug had beads of liquid on it (i thought it was gas at the time, but now based on what you are telling me it probably had water on it beading up on an oil/gasoline soaked plug)

before i pull the head, i would like to try to get the ski running...if it runs...i will use it for the next 2 months and then work on the top end in the fall...if it doesn't run then I will pull the head and inspect the cylinder walls. Does anyone see any reason that i shouldn't just try to do it this way? (i understand that it may not be the "By the Book" method, but i only have 2 months of summer left for the family and i am doing the repairs myself and tend to work pretty slowly)

If there is water in the motor...what is the correct method to get it out? Can these motors get hydro-locked?

I also want to thank you guys for all your help...without this forum, i would have resorted to getting a kayak instead! (just doesn't have the same acceleration)

 

[brock1]

running it this way will just create more problems but its your ski so do with it what you will....the pump will always resort to FULL OPEN in the evnt that the cable comes off or breaks....as far as getting the water out...YES it can hydrolock and the only way to get it out is to remove the plugs and crank the ski till no water shoots out the holes then go out and run it like you have never run it before...

 

[spx800]

That compression isnt bad, i run one of my skis with 100 125.

This is a joke right?

 

[blauther]

ok...checked compression again this morning...seems that the rear cylinder is getting worse (is that possible?).

Front cylinder had a consistent 130-135
Back cylinder was at about 85...then dropped down into the 45-50 range
I put some oil into the rear cylinder and it came up to 60psi

As you guys suggested...i pulled the head off and looked inside.
Rear cylinder is not smooth to the touch like the front one.

I will post pictures here tonight.

 

[El Toro 33809]

It would be odd to see a drop like that without running the engine.

 

[spx800]

150.. yeah lol a new engine... but yea the more compressesion the more power.. it will still go 40.

A new engine might be higher. My 800 which is original and 14 years old was still at 150/151 when i checked at the beginning of the season. You really never want to see more than 5 psi between cylinders.

 

[blauther]

Oiler Fail safe is not safe enough for Murphy....Murphys Law in Full effect!!!!!

Well...i learned that the Seadoo oiler has a fail safe mode in case of a broken cable...unfortunately for me i found out that if the cable comes out of the top keeper, the oiler arm is held in the idle position no matter what the throttle position.

Here is a picture of the throttle wide open with the cable out of the top keeper.

:banghead::banghead::banghead:

 

[blauther]

Here are the pictures of the cylinder. Can you guys give me some pointers on taking the cylinders off? any tips or tricks?

I will bring them to a machine shop tomorrow if i can get them off tonight.

How far can these be bored?

Thanks in advance for all your help guys!

 

[RutlandRacing]

This is a joke right?

Nah, it ran for like another 5 weeks then it went out... Ran good no joke lol