Bad starter or not enough battery/amps to turn rebuilt engine?

[mini4mw]

Hey all. I've rebuilt a 2005 RXT 1503 4tec. (new rods, pistons, rings, bearings, heads machines, cylinders honed, valves lapped, spark and other misc parts) I've rebuilt a few SxS engines, but first SeaDoo. Pistons were a little tight, but I could still rotate the crank with a breaker bar and thought I'd be all good. I've got everything back together, however, if the spark plugs are in I get less than a full rotation when I try to start. Hit start and I get a 1/3 rotation and stop. Take the spark plugs out and she turns over fine 5+ seconds until I let go of the start button. The compression stroke blows a towel up on spark plug hole when they are not in. I pulled jet pump (it was rebuilt as well with new bearing/prop/ring and is a little hard to turn as well) and pulled the hose for the SC to reduce compression. Same issue. Hooked up battery jump and separately tried jumping off my truck, same issue. Put some oil down the spark hole and it turned over a little easier, sometimes 2/3 rotation instead of 1/3 (with sparks in). I tried one spark plug and it still only made it 1/3 a turn. Sometimes after a failed start the dash resets like it had no juice and was then plugged in to a battery. I'm pretty sure if I could get it turning it will start.

I'm going to charge the jump pack, perhaps use a car battery use jumper cables to terminal leads on the RXT in a few days ( I don't have it at the house). That should at least eliminate the battery issue. If it still won't turn over, do you think replacing the starter will fix? It appears to be the original starter (bought RXT used) Man, I hate to think of tearing this thing up again to get at that starter.. it was such a pain removing and installing the engine, electrical and hoses.. Too much compression may be causing need for extra power for turning over, but there's not much I can do about that...

So I suppose the question is, if I double up on battery (jump pack and car battery to get her going, parallel for high amps at 12v) and it still wont turn over with spark plugs in, do you think its just a worn out starter? Before I got it, it did turn over but wouldn't start; rings had rusted in piston and coolant was in the oil, 20 psi on each cylinder. It had gouges from piston ring impact on the head and had been rebuilt. Guessing the head was not machined and caused the leak as the intercooler and oil cooler are not leaking and head gasket looked ok to the eye, it just may not have been sitting flat enough due to previous damage.

Any other ideas besides rebuilding starter/buying a new one? If the compression is high, is it possible an old starter doesn't have the juice? It had 230hrs on it if I remember correctly. I also rebuilt the SC and its in good shape.

thanks-

 

[mini4mw]

ok, tried out a new battery and it turned over fine today. Didn't start, but turned over with sparks in.

Old (new) battery was 20ah, ~300cca. New one is 30ah, 385cca. The jump pack itself worked fine this time after charging up as well. Not sure why the jump didn't work unless I needed to leave it on the jetski battery to charge. Perhaps it just didn't have enough cca.

New battery is Diehard from Advanced Auto Parts:
DHPWO Battery: TX30L Group Size, 385 CCA, 30 Amp Hour Capacity, For Off-Road Use
Part # TX30LA

As for the not starting, fuel pump is not kicking in. Tracked it down to wires inside the tank to the fuel pump motor itself or the fuel pump motor. Strange one I'm still working on figuring out.

 

[skiasylum]

FYI, the electrical circuits on your year ski can be somewhat temperamental, one of the few skis with both a mpem and ECM and the fuel pump is connected to both. Jumping the ski with your truck or a battery pack with a bad battery is risky to say the least and the service manual considers it a no no. Hopefully you didn’t fry the ECM or mpem and your fuel pump is the issue.

 

[mini4mw]

Not sure why jumping would cause the issue, but I have read that it is a no-no. Power comes from the battery and is only limited by what is requested. I could definitely see a short, incorrect connection or misuse cause an issue, but just adding amperage should not, which is all you do when you add a jump pack or connect another battery in parallel. I think there's just a higher than normal possibility of touching something and causing a short which can cause serious damage is why they say don't do it.. you are putting to high amp leads down deep in a chassis. No electrician here tho, just rebuild stuff.

After digging through tests I found that the fuel pump is not kicking on. Hindsight, not sure I've ever heard it turn on (before I rebuilt it would turn over, but not start and I don't recall hearing the pump when the key was put on) Pulled pump out and checked out the wiring. pin 1 and 4 are +/- for the motor. 2|3 are fuel gauge. If I check 1|4, I have 12.5v with key on and the pump motor disconnected. plug in the motor and its 0v. Seems like motor is grounding out, but strangely if I bond 3|4 where 3 is the neg for the gauge the pump turns on. Also not sure how I'm grounding out between 1|4 (0v) if the motor works fine when I bond 3|4 (-) and plug in the motor. So the motor works, just not on its own pins. Checked pins, bypassed some connections and same issue. Fuel pump motor is aftermarket so its been swapped before. I bought a new one of Amazon and we'll see what it does. Same behavior and there has to be a bad connection somewhere, or it works like its supposed to and motor was bad.

Thanks for the input.

 

[skiasylum]

I agree with you completely on your jump charge feedback, also I am not sure from the fuel pump explanation if your aware that the ECM is supposed to be switching the fuel pump on and off by providing its ground, so are you getting it to run by providing its ground from the fuel gauge ground. If that is the case the ECM is kaput which how they normally fail.

 

[mini4mw]

Thanks, didn't know that piece. And that would suck if it is as I've already put so much into this thing already.

I could see the ECM cutting ground fast enough where as soon as I plug in the motor it cuts it. That is what I'm seeing
12.5v with no motor connected on +/- leads, connect motor and 0v. Bridge fuel gauge ground and motor turns on.

I'm going to try the new motor this afternoon and see if the same result is found.

If it is the ECM, any recommendations on where to get a new one? Ebay, Amazon, etc? I guess I'll need a new key or the post reprogramed as well? I don't have the bip or bits software (forget offhand the brp software name) so there's an additional cost too.

Thanks

 

[mini4mw]

FYI, most of the stuff I buy from partzilla. Get a good discount and OEM.

 

[mini4mw]

Ok so the mpem is on the sidewall with the starter solenoid and the ECU is on top of the engine.

When you say 'thats how they normally fail' can you elaborate? You mean it's common for the fuel ground to be the one that stops?

Thanks

 

[skiasylum]

They fail by not providing the ground to components they are suppose to control, that’s what I meant by common. The mpem and ECM are both available on EBay. Westside Power Sports in Wayzata, MN program and sell mpems and ECMS. I would definitely give them a call if it’s not the pump.

 

[mini4mw]

Yea, so tried again, same result. Key on, 12.5v to pump pins. Plug in new pump, 0v. Bridge neg from fuel gauge to fuel pump, pump turns on.

 

[skiasylum]

Keep us updated on your progress

 

[mini4mw]

Will do. Right now I've sent ECM and mpem to the MN shop for testing.

 

[mini4mw]

Nick @ Westside plugged them in today and the fuel pump was turned off (assume in ECM and not MPEM). He had mentioned this happens when people go in there and fiddle around. The previous owner had lost the keys and had someone make one for him. They also tried to fix the non-starting issue (compression test would have shown why, it was less then 20psi on each cylinder, rings rusted tight on pistons). I'm guessing they turned if off by mistake. Hopefully I plug it in and it starts up pretty quick. I'll shoot an update next week when the parts come in.

 

[skiasylum]

Nick @ Westside plugged them in today and the fuel pump was turned off (assume in ECM and not MPEM). He had mentioned this happens when people go in there and fiddle around. The previous owner had lost the keys and had someone make one for him. They also tried to fix the non-starting issue (compression test would have shown why, it was less then 20psi on each cylinder, rings rusted tight on pistons). I'm guessing they turned if off by mistake. Hopefully I plug it in and it starts up pretty quick. I'll shoot an update next week when the parts come in.

I just read about that last week on a Facebook forum happening to guys with CanDoo Pros, they mess around with the fuel pump on/off function and it gets locked in the off position and won’t run again unless you input a unlock code. Crazy.

 

[mini4mw]

Got the ECM and MPEM back in and tested the fuel pump and its working like it should. As soon as I pop on the key it runs for a few seconds to prime. After putting it all back together, or the fuel pump anyway, I tried starting it up. It almost started 2-3x but the battery just isn't producing enough amps. If I add the jump pack it will turn over for 3-4 seconds 2-3 times and that is when it almost started. After that, its only 1-2 compression cycles.

I'm planning on checking it out tomorrow. I think its a bad connection somewhere so I'm not getting enough amps to the starter. I connected up a fully charged car battery with jumper cables to the positive and negative leads (internal battery disconnected) and it wouldn't even try to turn over, just solenoid click. So I'll just start peeling away, testing half way to the starter until I can find the culprit. I had cleaned all the connections with a wire brush.

One thing that is funny is that the dash cluster works, but sometimes only the RPM gauge goes to max and then back. The speedo doesn't move.

There's 4 small gauge grounds and 1 large. The one large goes to the 3rd hole on the end of the starter. The other two have screws that hold the starter to the chassis. Wondering if that ground to the starter, which is main, is in the wrong place. I know its clear of paint, but still may be a bad connection.

 

[mini4mw]

Ok, fixed the ground wiring as told by the service manual.
Rectifier -> battery
Battery ground -> engine
MPEM ground -> battery
ECM ground -> engine
There is one more ground, but the MPEM has two ground clips out of the same harness so I put both on the Neg of the battery.

Unfortunately same issue. Barely a cylinder rotation. Soooo

I took the starter out. With patience, string and a crowbar it came out. Screws are relatively easy with 1/4" ratchet. I had to tie a string through the 3rd hole on the starter, make a loop and then somewhat gently use a crowbar on the string against the head. I tried for 10-15 with my hand with no movement. It took another 10m ad breaks to get it out this way.

So I hooked the starter up to a 12v battery, seems fine. Took voltage and amp measurements while running:

10.4v
58 amps max, 28amp steady

Under no load, it should be the below per service manual
11.4 V
23 A max.
8600 RPM (can't test this, maybe slowmo on a phone?)

So under voltage and over amps. Searches and forums say if its not the ground, its the starter, so I guess I'm buying a new one.

I did open the starter up and bushings are worn, but not obviously bad. brush plate seems fine, good cooper look on most of it.

Anyone have any other ideas?

 

[mini4mw]

Put the new OEM starter in today. Before I did, I tested both old and new on a workbench. Car battery I was using was at 12.6v

under no load
old new Spec
volt 10.7 10.7 11.4
amps 27 23 -
max amps 60 50 23

Service manual says max amps in 23, but I wonder if that incudes the spike at start, which mine includes, or not. It seems to line up with the running amps more. Not much difference between the old and new, but still hopeful.

I put a new starter solenoid in as well as the starter. Tried turning it over, same issue, very slow turn over, 3 cycles first, then subsequent tries are less and less. I did put the voltmeter on to grab max amps during starting but I didn't do it the first time. Second time it went over 60amp limit, 3rd time (changed to 600amp) it reset grabbing max when I changed to 600 (didn't grab max) and 4th time battery wasn't turning over more than a cylinder rotation again; Needs to be charged up again.

I checked resistance from starter to neg battery - 0; battery to engine ground - 0; I'm thinking of putting a jumper on starter nut, one on battery neg and connecting to car battery to see what happens. When I connect the jumpers from car battery to onboard battery it doesn't seem like its connecting or able to pass enough amps. Same as when I just try turning it over from the start button. Positive and negative cables look fine, but thinking about at least swapping solenoid to starter and battery neg to engine case.

I had put everything back together so I pulled jet pump. I will be pulling turbo and drive shaft, but I had to stop for now. I'll just cover the turbo and drive with some duct tape for now. I'll see if I can start from there, if not, I guess I'm pulling the engine.

 

[mini4mw]

Removed jet pump, exhaust, turbo and drive shaft.

Tried firing up and i did get her to fire up 2-3x but only for a second. After several tries battery was dead again so we are done for the day.

I checked sparks for a gas smell and it did smell like it and they appeared a little wet, or at least 2 did. I'm still sick from a sinus/flu so hard to tell for sure. I also checked for spark again and found one coil cracked at the top near the connector and its no longer firing. I ordered up 3 new OEM coils and we'll start again. After it charges up I'll pull injectors and try to start and verify flow. The fuel was a little dirty and the fuel sock/filter was put in wrong last time the fuel pump was replaced so they could be clogged as well.

 

[mini4mw]

oh, the tests in patience...

Ordered coils and figured I should go ahead and test the injectors to make sure they are working right. When I fixed the fuel pump (or really tore it down and was testing) I noticed the sock was in the wrong place and dirt that was present in the tank could have bypassed and got some dirt in the lines.

When I quit yesterday, when trying to start the starter would spin but not engage the flywheel. Figured the battery was low as it was having a hard time turning over more than one revolution. Put it on a charger and let it be for the day. When I went back this morning, same issue. Try to turn it over and starter just spins. I can't hear the 1-way clutch engage, but I can hear it release/retract. When I let go of the start button, I can hear a light thunk of it retracting. Tried several times as perhaps its not lined up right.. nope. Just spinning and a thunk of it retracting.

Looks like I'm pulling the engine. It could be stripped gears from starter, which I could fix without pulling, but I'd need to get all the teeth out of the case. Anything with the one way clutch requires the engine to be pulled. I don't hear any flywheel engagement so I don't think its teeth. Sounds like the clutch is gone.

 

[skiasylum]

I am just going to check here, and to make sure that when you rebuilt the motor, did you spin the motor with the head off and make sure it turned easily. You mentioned earlier that the pistons were a little tight. If the motor was sunk and then hydro locked it could have bent rods. Valve stems bent? Crank and rod bearing clearances? Piston clearances? Again just checking. If you stripped some teeth something seems off.

 

[mini4mw]

New rods/pistons/rings. Machined head, cylinders honed. Original valves/springs but lapped. New oil seals on valves. Orig crank/balance, new bearings. New oil pumps front and rear.

I could spin it with a breaker bar, but it was tighter than others I've put together.

Right now the bendix isn't catching the flywheel for some reason. It's extending as I can hear it retract, but it just spins. Right before this it started up for a second twice. That's when I checked spark again and found a coil cracked and not sparking.

Unfortunately I don't see a way to get to the bendix without pulling the engine.

 

[mini4mw]

Pulled engine and the spring clip that held the gear on the start came off, along with the gear. So starter was spinning but there was no gear to engage the bendix. Couldn't find spring clip, which was new with starter, so I used the original. Putting everything back together..

Used a magnet to try and find the spring clip to no avail.

 

[mini4mw]

Sweet, found it (spring clip) lying on the ground below where I pulled the magneto cover off.
Not damaged or broken. When I initially put it on (when I put in the new starter) I thought it was a little loose, but being new I ignored it. Just the way it is right?? I should have gone with my gut and tightened it up a little.

 

[mini4mw]

Got the engine back in today and all connected up. Left injectors out and turned over the engine. Injectors spit gas but they did all fire at the same time which is strange. Put inectors in and hooked up new coils with plugs, leaving them out to test for spark. Turned over and no spark. Put old coils on, same. Before I pulled engine 2 of 3 coils fired. Just have to go through electrical and fuses and see what I can find.

 

[mini4mw]

Getting too busy to mess with much.. and getting too cold..

I had the plugs in the new coils and the coils sitting pointing in the air so I could watch for spark. Still none. For fun I put the coils and plugs back in and turned it over and it fired once and then the battery couldn't turn it over fast enough again.

Why would it fire with the plugs in? I know without coils the plug has to ground to generate a spark, but I didn't think that was necessary for individual coil packs. After all I did this before and I saw sparks on 2 of 3 which is how I determined one was bad (not to mention the plug was at 70 degree angle and not 90).