Seadoo 717 hard start

[skrillac]

Last year I had the 96 gti out on the lake. I took it over to a friend's dock, and shut it off for a few hours. Then it wouldn't start. Ended up discharging the battery trying to get it to start again. Finally was able to start it again after charging the battery up.

I rebuilt this ski a few years ago. Completely went through the fuel system. Osd Marine carb rebuild kits, new mpi grade fuel lines, new fuel selector, new check valves/relief valves for fuel system. I set carbs by the book. I believe when I measured popoff after rebuilding the carbs I got 40-42psi for each carb. I also did a top end and replaced the rotary valve and cover. Top end was from fullbore. Rotary valve and cover replacement came from sbt.

Whenever I put the ski away I fog the cylinders and either clean or replace spark plugs. Then once a year I winterize. Whenever I take the ski out it starts everytime. It may take a bit longer than my other 717, but it's not that noticeable. Now that I think about it, I do normally have to pull the choke and give a little throttle for awhile to start cold. But after it's warm, it's really hard to start after it's been shut off.

From the manuals troubleshooting section, it says to check rotary valve clearance and timing for hard starts. Today I performed the 45 degree feeler gauge test on both sides. Removed the valve cover oring, put the cover back on and torqued to 15lbft. Spec is 0.010 - 0.014in . On both sides of the cover, I am probably somewhere between 0.012 and 0.013 in. I know for certain I wasn't able to fit 0.014 in, so I don't think my clearance is bad. I'm gonna check the valve timing angle again.

Is there anything else to check that would cause this hard start when warm?

 

[skrillac]

So apparently my timing degrees were off by about +8-10 degrees. I checked twice. Manual says spec is plus or minus 5. This time I used an actual degree wheel instead of printing something out online. Also used an tdc indicator to find tdc of mag side piston. After re-setting timing, I checked 3 separate times mag side piston tdc by manually spinning the engine with the plugs out several times. Now the timing looks like +3-4 degrees off from the degree numbers given in the manual, but its inside the allowed tolerance of plus or minus 5 so I should be fine.

I haven't had a chance yet to test the ski but I will probably this weekend. To anyone who's done this timing job before, is this an acceptable "spot" to be in?

 

[skrillac]

Took the ski out today. Started fine after sitting for a year or so. Drove it around for about an hour. Brought it back to the launch and tied it off for 20 minutes. Hopped back on it and it would not start. Ski ended up beeping once and flashing the red light for low battery. I may have been able to crank the starter 2 or 3 times about 30 secs each time.

So i've verified rotary valve clearance and timing and it still hard starts like this when warm. I'm gonna go and get the battery load tested because maybe that's my issue. Before I could even put the ski in the water, I spent 2-3 hrs charging the battery up to 12.4 volts. I have the factory starter on this ski and have opened it up before to clean commutator, clean brushes etc.

Anyone have any recommendations?

 

[burtshaver2021]

It sounds like you’ve done everything that needs to be done and done it proper. Hopefully a new battery is all that’s needed. 12.4 isn’t great

 

[skrillac]

I left the trickle charger on the battery overnight, about 12 hours. Its one of those 750mA ones with "smart" functionality. Read 12v this morning. Probably battery is bad. I'll do my due diligence and check regulator and charging later by starting the ski on the trailer later. Its just crazy. Its a legend agm battery from napa. I thought it would last a bit longer than 3-4 yrs.

@burtshaver2021 do you have any recommendations on battery? i've only ever used these 325CCA legend agm batteries from napa. just curious.

 

[burtshaver2021]

I left the trickle charger on the battery overnight, about 12 hours. Its one of those 750mA ones with "smart" functionality. Read 12v this morning. Probably battery is bad. I'll do my due diligence and check regulator and charging later by starting the ski on the trailer later. Its just crazy. Its a legend agm battery from napa. I thought it would last a bit longer than 3-4 yrs.

@burtshaver2021 do you have any recommendations on battery? i've only ever used these 325CCA legend agm batteries from napa. just curious.

It’s hit and miss with batteries, one thing I will say is try to store them in a cool place which is difficult to do with a Seadoo. I think the battery is toast. I had an Interstate battery that lasted me 9 years roughly, so when I needed another battery I got another Interstate, same model battery and I don’t think I even got 2 years out of it. Bought another Interstate but this time it was model number starting with Pwc for personal water craft and again, less than 2 years. I now have 2 motomaster AGM’s, one I bought at the beginning of last winter for one of my snowmobiles and one I just bought a couple weeks ago, 186.00 after tax. All I can say is keep your receipt and don’t expect much more than 2 years.

 

[skrillac]

@burtshaver2021 would you recommend i remove the batteries from my skis and charge them in the garage or just charge them in the skis? My garage is a bit hotter than where they are sitting currently under a carport.

My skis are parked under a car port and covered with ski covers for each. I'm planning on using x2 of these chargers (one for each ski) and just leaving them plugged in throughout the year with the ski covers on.

 

[burtshaver2021]

@burtshaver2021 would you recommend i remove the batteries from my skis and charge them in the garage or just charge them in the skis? My garage is a bit hotter than where they are sitting currently under a carport.

My skis are parked under a car port and covered with ski covers for each. I'm planning on using x2 of these chargers (one for each ski) and just leaving them plugged in throughout the year with the ski covers on.

If it was me, I would disconnect t the batteries before charging. These are so finicky with voltage spikes damaging the electronics I wouldn’t take any chances. Shouldn’t be any need to charge them up during the season I wouldn’t think. In the skis will be fine but disconnected. I’m really just saying don’t leave or store your batteries anywhere that is crazy hot like a vehicle

 

[skrillac]

@burtshaver2021 i've never disconnected the battery terminals before when charging. i only ever disconnect the cable that grounds the mpem to the engine block (which then grounds to the battery negative). waaay easier to just unplug that cable there by the engine serial plate. oh ok then i'll just leave them charging during the off season. thanks.

 

[skrillac]

So i replaced the battery yesterday. Charged it up as a precaution with the "smart" charger. 13.1 volts. Took it out and wow the ski was really hard to start. Had to hold throttle wide open and it barely started after cranking cranking cranking. Took like 30 secs for the ski to reach idle too once it started. Drove it around for about an hour and brought it back. Let it sit for 20 minutes, would not start again.

After I started the ski initially, I was able to check voltage at the battery. 12.6v after all that cranking and the ski running at idle. Shut the ski off to go move the truck/trailer off the launch ramp, 12.6 volts with the engine off. Rode the ski around for an hour, came back to the dock and checked voltage with the engine running at idle again. 13.1 volts. So i think my rectifier/regulator is good.

Came back and tested compression and spark. 133psi on both pistons. This is basically the same pressure reading I got after doing the top end a few years ago. I run the green full synthetic oil in this ski. Plugs were a chocolatey brown and smelled kindof sweet. Spark was consistent in both plugs.

When I tested spark, I accidentally had the fuel selector set to off (I replaced this fuel selector years ago with the top end). Does this indicate a fuel leak through the fuel selector? I only had it running for maybe 10 seconds and then shut it off. I also did check rpm on the trailer. It seems this ski wants to run at 1500rpm on the trailer, which is wrong I believe it should be 3000rpm. I remember setting the ski to 3000rpm on the trailer years ago. I gave it some throttle and watched rpm return to around 1500-1600rpm each time. Which is weird, because I didn't notice low power while on the water doing wot.

At this point, I'm gonna go through the fuel system again and pressure/pop off test everything I can. Then go through the carbs again maybe.

 

[burtshaver2021]

You need to check the volts on the battery at rest, then at idle, then at 4500 to 5500 rpm. Yes, the idle is low, you are correct, it should be about 3000 rpm on the trailer. There may have been enough fuel in the system to run it for 10 seconds with the selector in the off position, not necessarily leaking. I’ve tested the selector valve with a a few pounds of vacuum in each position to see if they are sucking air. Your low idle could just be the idle screw not set correctly. I believe you turn it out to raise the idle. The hard starting could be a few things, possibly out of spec rotary valve cover or grooved rotary valve cover, fuel pump not sealed, dirt in the low speed circuit of the carb. You had 133 pounds of compression after doing your rebuild a few years ago and now it’s at the same compression correct? That’s good. When you did the top end rebuild did you have the cylinders bored or measured for out of round, taper? Do you know if the cylinders were in spec?

 

[burtshaver2021]

Just read through your first post again, rotary valve cover is new from SBT, new top end from Full bore, so it was a cylinder swap? 133 seems very low for a full top end rebuild. I’m really at a loss as to why you are having the hard start issues

 

[skrillac]

You need to check the volts on the battery at rest, then at idle, then at 4500 to 5500 rpm. Yes, the idle is low, you are correct, it should be about 3000 rpm on the trailer. There may have been enough fuel in the system to run it for 10 seconds with the selector in the off position, not necessarily leaking. I’ve tested the selector valve with a a few pounds of vacuum in each position to see if they are sucking air. Your low idle could just be the idle screw not set correctly. I believe you turn it out to raise the idle. The hard starting could be a few things, possibly out of spec rotary valve cover or grooved rotary valve cover, fuel pump not sealed, dirt in the low speed circuit of the carb. You had 133 pounds of compression after doing your rebuild a few years ago and now it’s at the same compression correct? That’s good. When you did the top end rebuild did you have the cylinders bored or measured for out of round, taper? Do you know if the cylinders were in spec?

The rotary valve and cover are fairly new. I bought both from SBT when i did my rebuild maybe 3 years ago. I actually just checked clearance and timing of the valve. I'd say it was somewhere between 0.013 - 0.014 in for both inlet holes. Timing is +3-4 degrees off the mark. Both of those are within spec. I did change rotary timing earlier in this thread. Originally it was +8-10 degrees off. I haven't noticed a difference in starting/running before/after changing the timing closer to the correct position. My skis I don't think have the accelerator pumps. They are operated via a pulse line from the mag side piston. Compression is roughly the same, I wanna say it was 135 after rebuild. I had cylinders bored 1mm over by fullbore before they went out of business. I never mic'd them if that's what you're asking. All fullbore did was bore my cylinders and send me wsm pistons/rings/gaskets for the rebuild. I rebuilt my own carbs with osd back to oem kits. Screws in carb were set by the book. My tach I've been using is a digital one, set to 2P1R (supposedly works with 2stroke 2 cylinders).

 

[burtshaver2021]

Just reading through the mikuni carb manual here and you turn the idle screw in to increase idle. This will open the throttle plate allowing more fuel in, could be your hard start issue. If not I’m thinking you have some dirt in the low speed outlet hole. Did you have good flow of carb cleaner out the small holes ( low speed outlet hole and bypass holes ) in the carb throat? I’m really thinking this is it, if you go through the carb again, follow @mikidymac carb thread. The low speed outlet hole is responsible for fuel at idle and the bypass holes are responsible up to 1/4 throttle and those are issues for you so…. Throttle valve is in good shape? Not bent ?

 

[burtshaver2021]

One other thing, do you have good black fuel line going to the pulse fitting on the carb?

 

[skrillac]

@burtshaver2021 i think you are right about it being the carbs.

The other day i hooked the ski up to the hose to run it and check rpm at idle again. i must have missed it last time, but water was spraying out of the exhaust pipe where it meets with the manifold. The nut on the stud had come loose. Pulled the exhaust apart cleaned out the threads on the manifold, threads on the bolts and stud. This time i got a stainless steel nut with nylon insert for the stud. Blue loctited everything down. New exhaust gasket. Hooked it up to the hose today and no leaks

I might add the ski starts easily on the trailer. Starter maybe makes 2 revolutions and the engine starts. I did have a bit of a problem setting idle rpm. When I start the engine it takes a few seconds to get to the idle rpm, faster if I rev the engine past its idle speed. When I was adjusting the idle speed while it was running I noticed that the idle speed didn't immediately increase as I turned the screw in. Infact, I turned the idle up to see at what point it would automatically jump, but it never did (or at least i stopped turning it up and revved it instead). After the rev, the speed jumped and held at 3700 rpm or so. I think you are right, I'm having problems with fuel at idle and some point with throttle. Past that point, I'm fine.

I did test the black fuel pulse line. I blew air into it after spraying it with 409 so I could see bubbles if they appeared, which they didn't. I didn't feel any restriction, probably because the piston wasn't blocking the exhaust port. But I'm fairly certain that hose is fine.

I'll re-read through that carb rebuild thread and take a look at mine. May just end up buying another osd marine back to oem kit.

 

[burtshaver2021]

Yeah, I think those exhaust bolts are known to loosen up, I put a line with paint marker on the heads of the bolts so I can easily tell if they have turned out at all. The OEM kits are expensive, being how you just put a kit in, I would be apt to take it apart, make sure you have good flow from pilot jet to the small holes in carb throat, put it back together, pressure test it and try it

 

[skrillac]

@burtshaver2021 I just now verified the pilot jets in each carb aren't blocked. Blew them out with brake cleaner before/after unscrewing them. PTO side carb popoff looked like between 35-36 psi. Mag side carb looked like between 40-42 psi. Both carbs held pressure at 20psi for 10 minutes. I stopped the test at 10 minutes. I tested popoff/leakdown according to @mikidymac thread.

I'm gonna try and send it and see where I'm at. Worst case I just redo the carbs with an osd kit.

 

[burtshaver2021]

If you haven’t already put them back together, did you verify carb cleaner was flowing through the pilot circuit into the 2 tiny holes in the carb throat? With the pilot jet out spray the carb cleaner in there and you should see it flow out those holes, if it doesn’t then the machine is not getting its fuel at idle and up to 1/4 throttle. The test for the needle is 10 pounds not 20, not sure if 20 will hurt anything, but better safe

 

[skrillac]

If you haven’t already put them back together, did you verify carb cleaner was flowing through the pilot circuit into the 2 tiny holes in the carb throat? With the pilot jet out spray the carb cleaner in there and you should see it flow out those holes, if it doesn’t then the machine is not getting its fuel at idle and up to 1/4 throttle. The test for the needle is 10 pounds not 20, not sure if 20 will hurt anything, but better safe

I just now retested that. Sprayed brake cleaner through the pilot jet on both carbs. There was a steady spray of brake cleaner through several holes. I wanna say I saw probably 3 different streams. All streams came out of holes behind the throttle plate in the throat of the carb. Now that I've stopped to take a picture of the throat it looks like there are 4 different holes there. I know for certain I saw brake cleaner come out the big one. I'm pretty sure it sprayed out of all of those smaller holes too. Both carbs.

 

[burtshaver2021]

If you screw the low speed screw in one turn, it helps the fluid through the low speed circuit. I can’t remember if there are 2 or 3 tiny holes

 

[skrillac]

If you screw the low speed screw in one turn, it helps the fluid through the low speed circuit. I can’t remember if there are 2 or 3 tiny holes

It actually turns out that I had the low speed screws turned out exactly one turn from closed. I can't remember why I did this. Went ahead and turned them back closed and backed out 1.25 turns like the manual says.

The manual says:

"Check that engine idles and runs smoothly. Make
sure engine reacts quickly to throttle lever depres-
sion. If necessary, readjust low speed screw
(±þ1/4 turn)."


It seems like I've had problems with the engine reacting quickly to throttle lever depression. Once I gave it throttle before going through the carbs again, it would slowly lag down to where the idle was set. From basic research online, this hanging rpm symptom seems to indicate a lean condition at that idle / low throttle position. I guess I've never noticed because I run the ski mostly at full or most throttle, and that gets the plugs nice and chocolatey brown. Since going through the carbs again, I've turned the low speed screws 0.25 turns out from where they were, in effect enrichening the fuel/air mixture a bit more at idle/low rpm. It follows that according the part of the manual above, I'd turn the screw out another 0.25 turns to enrichen further to help with that hanging rpm if necessary.

I'm not sure how this sort of issue presents sporadically. It seems like sometimes the jetski was very easy to start. Sometimes not, even if the battery was charged.

 

[burtshaver2021]

looking forward to hearing how it starts now, fingers crossed. Set the idle to 2800-3000 rpm out of the water then it should idle at 1500 in the water.

 

[skrillac]

looking forward to hearing how it starts now, fingers crossed. Set the idle to 2800-3000 rpm out of the water then it should idle at 1500 in the water.

Just have one more thing to address other than tuning and I'll let ya know. I decided to pressure test everything one last time with all the hoses hooked up (except the input fuel line). Found the y fitting (#46) leaking air. Took it out and plugged the hoses with some bolts. Carbs hold air at 10psi for several minutes. No leaks. Just need to replace this y fitting with something from an auto parts store. Preferably plastic. I'm not sure if it was leaking to begin with. May have been. I was testing each individual carb for leak down at first.

 

[Sea-doodle]

Any updates to this? I’ve also been having a hard start issue like you describe, although not quite as hard. Mine will eventually start with a combination of hitting the choke and then feathering some throttle. After starting I have to baby the throttle to keep it running and if I give it too much throttle it kills the engine. After I baby the throttle the engine finally clears out and I’m back to wide open ripping and the ski runs great.

I did find that my idle was set low, 1500 on trailer. Did this because I installed a new tiny tach and I had it set to the wrong setting. Seadoo 2 stroke apparently fire twice per revolution and I had it set differently giving a false rpm reading of twice of what it actually was. I haven’t had the ski out since adjusting the rpm correctly. Fingers crossed it was the cure.

I haven’t air tested my fuel system (besides my fuel tank) but I went through it last year and replaced everything, including that y fitting that was leaking on yours.

Carbs are rebuilt with osd back to oem kit.

Compression is 140 on both cylinders. I have not checked rotary valve or squish.

I’d love to know if you fix yours! Good luck.