2000 Speedster w/ Merc 240EFI - won't start after warmed up

[TurboDawg]

Hey kids,

I've combed the forums, and incorporated as much as I could find before posting, so that I wouldn't waste anybody's time. I'm going to include everything I think may be relevant, so please bear with me.

First, a quick disclaimer...I just bought this boat, so I don't have a lot of experience with it, and it's my first jet boat. I am fairly mechanically inclined with cars and such, but new to the Merc.

OK, so...sitting in the driveway or in the water when first launched, the boat fires right up and runs fine. Does smoke a bit, but being new to the boat I'm not sure if that is to be expected. In the water the engine runs great - nice and smooth, and an almost intimidating amount of power. At idle, it still does seem to smoke a bit more than I would have expected, but again...not familiar with the engine.

Here's the problem: Once the boat has been run for 20 or 30 minutes, if you turn it off it won't re-start. It turns over, but generally only briefly. As soon as it kicks (a cylinder fires) the starter disengages. (I presume this is normal, as you'd want it to when the engine starts). Occasionally you can get it to turn over for as much as a couple of seconds, but it does not start. I can tow the boat home, let it sit for an hour and it will still not start. The next morning, however - starts like a champ. (We're talking 50° weather here, so the engine certainly should have cooled in 30-60 minutes)

I read numerous posts that sounded exactly like my problem, the majority of which pointed to the temp sensor, so I replaced the (port-side) temperature sensor. This was particularly encouraging because when I inspected the old sensor, I found that one of the previous owners had inserted a 220 ohm resistor inline in one of the brown/black wires...making me think there must have been a problem with the sensor. (For the record, I used part number 13536A14) I did *not* leave the additional resistor inline when I put in the new sensor)

Next time I took the boat out, we stopped after about 15 minutes, and the boat stopped and re-started twice - I was psyched! But then I couldn't get it to start when loading onto the trailer, and again when I got home to rinse her out...so it seems not to have fixed the problem.

One member posted that replacing the sensor did not fix his problem, but then he switched the two brown/black wires, and it did. I have not tried this, (found the post after returning home from the coast) but it makes little sense to me since the directions did not specify any difference between those wires, and I *thought* that they were just the two sides of the resistor circuit, so it shouldn't matter. I can try this though, when I am at the coast this weekend, if you think it should make a difference.

The only other thing I can think of is that I was careful not to over-tighten the sensor clip during installation, since it looks like the body is plastic. Is it possible that it is not making proper contact?

Any help here would be awesome. She runs so well and is so much fun, and starts SO easily when cold, it just doesn't seem like this should be hard to figure out...but I can't safely take her anyplace if I can't count on her starting.

Thanks SO much in advance.

PS: I have a picture of the old sensor with resistor attached, if that would help, or be of any interest.

Thanks!!

 

[Tim75]

Bad new$

Hey kids,

I've combed the forums, and incorporated as much as I could find before posting, so that I wouldn't waste anybody's time. I'm going to include everything I think may be relevant, so please bear with me.

First, a quick disclaimer...I just bought this boat, so I don't have a lot of experience with it, and it's my first jet boat. I am fairly mechanically inclined with cars and such, but new to the Merc.

OK, so...sitting in the driveway or in the water when first launched, the boat fires right up and runs fine. Does smoke a bit, but being new to the boat I'm not sure if that is to be expected. In the water the engine runs great - nice and smooth, and an almost intimidating amount of power. At idle, it still does seem to smoke a bit more than I would have expected, but again...not familiar with the engine.

Here's the problem: Once the boat has been run for 20 or 30 minutes, if you turn it off it won't re-start. It turns over, but generally only briefly. As soon as it kicks (a cylinder fires) the starter disengages. (I presume this is normal, as you'd want it to when the engine starts). Occasionally you can get it to turn over for as much as a couple of seconds, but it does not start. I can tow the boat home, let it sit for an hour and it will still not start. The next morning, however - starts like a champ. (We're talking 50° weather here, so the engine certainly should have cooled in 30-60 minutes)

I read numerous posts that sounded exactly like my problem, the majority of which pointed to the temp sensor, so I replaced the (port-side) temperature sensor. This was particularly encouraging because when I inspected the old sensor, I found that one of the previous owners had inserted a 220 ohm resistor inline in one of the brown/black wires...making me think there must have been a problem with the sensor. (For the record, I used part number 13536A14) I did *not* leave the additional resistor inline when I put in the new sensor)

Next time I took the boat out, we stopped after about 15 minutes, and the boat stopped and re-started twice - I was psyched! But then I couldn't get it to start when loading onto the trailer, and again when I got home to rinse her out...so it seems not to have fixed the problem.

One member posted that replacing the sensor did not fix his problem, but then he switched the two brown/black wires, and it did. I have not tried this, (found the post after returning home from the coast) but it makes little sense to me since the directions did not specify any difference between those wires, and I *thought* that they were just the two sides of the resistor circuit, so it shouldn't matter. I can try this though, when I am at the coast this weekend, if you think it should make a difference.

The only other thing I can think of is that I was careful not to over-tighten the sensor clip during installation, since it looks like the body is plastic. Is it possible that it is not making proper contact?

Any help here would be awesome. She runs so well and is so much fun, and starts SO easily when cold, it just doesn't seem like this should be hard to figure out...but I can't safely take her anyplace if I can't count on her starting.

Thanks SO much in advance.

PS: I have a picture of the old sensor with resistor attached, if that would help, or be of any interest.

Thanks!!

I have had exactly the same problem (except in 75º water) as have many others here. Sounds like the dreaded TPS throttle position sensor. Dreaded because if it is bad, it is STUPID expensive. Highest price I found for any car TPS was about $100. Merc is $500! There are threads here on how to check it. You need an ohm meter- analog preferred and a couple of small alligator jumper cables. 10 minutes to check, 10 more to change, hours of work to pay it off.

Doc Honda is the expert here-- he will ask for engine serial number and engine compression. Have you checked the spark plugs?

 

[Coastiejoe]

Common issue with Seadoo boat restarts is, lack of quality air.

Run the blower for at least 4 minutes and see if the problem goes away. For whatever reason, after they warm up and the you sit with them off for a bit there simply is not enough "burnable" air inside the engine compartment area. Without good air they will not run.

This problem is self correcting when moving do to the design of the vents. When sitting there is no way for the bad air to get out and good air to get in without running the blower.

 

[TurboDawg]

Yikes! I had really, really hoped that wouldn't be the problem. I'll look forward to the Good Dr. chiming in, but in the mean time I'll find the posts on testing the tps. Unfortunately the boat is not nearby so I'll have to wait to do the actual test and to get the engine number. (Feeling stupid now that I didn't think to get the number and write in the front of the shop manual).

I guess the resistor on the old head temp sensor was a red herring; maybe the former owner tried it rather than pay for the tps.

I didn't check the spark plugs (against my own better judgement) because people were telling me that if it were the plugs, it would start hard and run rough cold. Also, the former owner claimed to have changed them at the start of last season. I'll check them as well...good to see if they're black or oily from running rich.

Oh, and my Engine Serial # is 0E376027 (found it written in the repair manual - yay former owner!).

Don't suppose there's any chance it's the throttle guardian (he says wishfully ;o)

 

[TurboDawg]

Common issue with Seadoo boat restarts is, lack of quality air.

Run the blower for at least 4 minutes and see if the problem goes away. For whatever reason, after they warm up and the you sit with them off for a bit there simply is not enough "burnable" air inside the engine compartment area. Without good air they will not run.

This problem is self correcting when moving do to the design of the vents. When sitting there is no way for the bad air to get out and good air to get in without running the blower.

I kind of doubt that's the problem, as I've tried to get it started for quite a while with the hatch open and the engine cover removed...should have been a ton of clean air...but I appreciate the suggestion and it's easy enough to try! Thanks!

 

[Dr Honda]

There are a few COMMON things that will keep a Merc from re-starting.

1) Bad Port side temp sender

2) Bad TPS

3) Bad air


Along with that list... there can be a bunch of other things that could make a restart hard.

4) Dirty sparkplugs/weak spark.

5) leaking fuel. (flooding the engine while it sits)

6) bad Throttle guardian

7) other electrical.

8) other Fuel.


OK... That's a huge an generic list. BUT... the common (first 3) are normally where the problems are. THe Merc engine will smoke, but if it seems excessive, and doesn't clear up when off idle... then i'm 90% sure it's one of the first 3. Basically, if the TPS or the temp sender is bad... the ECU will default to "Full" fueling for safety. (lean 2-stroke = melted engine)

Since you have them manual... it lists the tests for both the TPS and the temp sender. Grab a meter and check them.

With that all said... my Islandia will have a hard time re-starting if I don't use the blower to draw in fresh air. It will crank, pop, and kick off the starter. (sound familiar?) When it finally does catch... it will die as soon as I give it any throttle. But, if I simply kick on the blower... and give it a minute or so... it's perfect. The reason I figured that one out, was because I had a faulty switch, and the blower wasn't always coming on. (it's not easy to hear on my big boat)



With your symptoms, I would say it's a very small chance that it's a guardian. they normally cause popping, and random issues. BUT, personally, I think it's a hunk of crap, and needs pulled from any Merc. It's also the same of the spark plugs. if it's running and starts cold... they are probably OK. But, it can't hurt to put in a fresh set. If you are dealing with a light flooding issue... a clean/bright spark will help fire it off.


If you check the first 3... and are still having issues... I will help you figure it out.

 

[TurboDawg]

There are a few COMMON things that will keep a Merc from re-starting.

1) Bad Port side temp sender

2) Bad TPS

3) Bad air


Along with that list... there can be a bunch of other things that could make a restart hard.

4) Dirty sparkplugs/weak spark.

5) leaking fuel. (flooding the engine while it sits)

6) bad Throttle guardian

7) other electrical.

8) other Fuel.


OK... That's a huge an generic list. BUT... the common (first 3) are normally where the problems are. THe Merc engine will smoke, but if it seems excessive, and doesn't clear up when off idle... then i'm 90% sure it's one of the first 3. Basically, if the TPS or the temp sender is bad... the ECU will default to "Full" fueling for safety. (lean 2-stroke = melted engine)

Since you have them manual... it lists the tests for both the TPS and the temp sender. Grab a meter and check them.

With that all said... my Islandia will have a hard time re-starting if I don't use the blower to draw in fresh air. It will crank, pop, and kick off the starter. (sound familiar?) When it finally does catch... it will die as soon as I give it any throttle. But, if I simply kick on the blower... and give it a minute or so... it's perfect. The reason I figured that one out, was because I had a faulty switch, and the blower wasn't always coming on. (it's not easy to hear on my big boat)



With your symptoms, I would say it's a very small chance that it's a guardian. they normally cause popping, and random issues. BUT, personally, I think it's a hunk of crap, and needs pulled from any Merc. It's also the same of the spark plugs. if it's running and starts cold... they are probably OK. But, it can't hurt to put in a fresh set. If you are dealing with a light flooding issue... a clean/bright spark will help fire it off.


If you check the first 3... and are still having issues... I will help you figure it out.

Thanks, Doc - this is awesome. It's killing me that I'm not going to be able to test this until the weekend after next, but I *really* appreciate the feedback! I will definitely do the plugs and try the fan - both are cheap, easy fixes. I'll likely yank the guardian too, since it seems to introduce more potential problems than it does safety.

The temp sender is brand new (replaced it, convinced that it was the problem). I will test the TPS and pray that it's not the problem, since I priced it at $483 yesterday. Just out of curiosity, if it tests out within range, is there an adjustment to it, and could that be the problem? Also, is failure usually due to breakdown, or do you think spraying some electronics cleaner in there could clean up the resistor coil and improve the situation?

Oh, and the guy who switched the two brown/black wires on the sensor and it fixed the problem...that's got to be a fluke, or the wires weren't well connected the first time, right?

Sorry for the additional questions that I can probably figure out on my own with the boat in front of me, but without it my mind has latched onto this and won't seem to let go.

Y'all are great and I really appreciate the help. Assuming this doesn't turn into a black hole that convinces me to get rid of the boat, I see a premium membership in my future )

Thanks again!

 

[Dr Honda]

Swapping the temp sender wires was a fluke. As you already said... a resistor circuit isn't polar. That's why the wires are the same color, and have the same plug. If they needed to be polar, they would be different colors, and have opposite plugs. Most likely, he had a bad connection, and simply pulling them apart, and putting back together made it better.

**EDIT**

Did you clean the head, and put a small amount of thermal grease in the pocket of the temp sender? If it's not touching, and have good clean contact... it could be reading as if it's a cold engine, and give you too much fuel on start up.

**END***

Just an FYI... a resistor in the temp sender system is an old automotive trick. Basically, when you have a CAR/TRUCK that is emission controlled... they run slightly lean. This is the best point to lesson the pollution out the tail pipe. SO... if you put in a resistor, you make the ECU think it's cold, and it will give you a little more fuel, and in turn... you make a little more power. It works... but we are talking about 5 hp in the upper RPMS, and when it's pushing a +3000 Lb car... you will never see a difference.

In our Merc engines... they didn't have to meet any kind of pollution standard, and since they are 2-strokes... they don't run lean. So... basically... I think the last owner had just enough info to be dangerous. (just wasted fuel)

Yes... you can adjust the TPS, and reflection on the thoughts above (and assuming the last owner didn't really know what he was doing) there is a chance that he just cranked the TPS over, to give max fuel. SO... you may find yourself lucky, and it's just improperly adjusted.

The TPS is sealed... so you can't clean the internal parts. Also... the few I've opened up... the traces were just warn out.

On the spark plugs... I put in a fresh set every season. They aren't as cheap as regular pugs... but for $30... I would rather know, that they are up to the job. Also... if they have been overheated, the internal resistor can burn, and give a weak spark.

 

[TurboDawg]

You are the man - thanks!

I did not put thermal grease in the socket - didn't know it existed...any particular or resistance rating you recommend? I will do that first thing, along with plugs.

I will also check out the manual for details on TPS adjustment. I would love to find that is the problem.

I will report back after the next cycle of tests!


Thanks also for the resistor education - very cool to know what that was *supposed* to be doing.

 

[Dr Honda]

There isn't any specs on the thermal grease. It just helps transfer the heat to the sender. Ive even used regular synthetic grease. You just need a little blob on the end of the sender.

 

[Crazyhorse3469]

I have a 2000 challenger 2000 iv checked spark made sure I was getting fuel and have yet to get it to start. I went and looked at the boat last Saturday it started up fine bought it Thursday and have yet to get it to start,will turn over fine but will not start?


Sent from my iPhone using Tapatalk

 

[Coastiejoe]

I have a 2000 challenger 2000 iv checked spark made sure I was getting fuel and have yet to get it to start. I went and looked at the boat last Saturday it started up fine bought it Thursday and have yet to get it to start,will turn over fine but will not start?


Sent from my iPhone using Tapatalk

Do a compression test to see where you are. It might be better to start your own thread if your issue gets to be a more in depth item. It helps to keep things straight.

If you are getting fuel spark an have good compression it should run. That said, any if those can be off a bit an cause a no start situation. How did you test to see if you are getting fuel? And spark?

 

[TurboDawg]

OK....

I've replaced all of the spark plugs and put thermal grease on the head temp sensor. The old plugs - which are supposedly only a season old - look pretty black to me. I've included links to the pics of the plugs...couldn't seem to get it to insert them directly. I'd love to know what you think; I'm not as familiar with 2-cycle engines. (Doc - could the resistor I mentioned in the head temp sensor make it run richer and cause this? Any other suggestions?)

Up next is to find/adjust the TPS, and find/adjust the oil mixture mark. Thought I'd have gotten to these by now, but when I got in there I found that the low-speed throttle cable from the helm was disconnected, and I got side-tracked trying to connect and adjust that.

Here are links to the pics of the plugs:
All six plugs
Single plug close-up(worst one of the bunch)

Thanks for any help!

===

Update:

I was able to test the TPS and the values were very much in line with the specs... .204 at idle and increasing pretty smoothly up to just under 7v at max. Hopefully this means that I've just saved $500.

Weather kept me out of the water this weekend, but I started her in the driveway and ran her very briefly. Though it's far from a quantitative analysis, I have to say there was clearly less smoke than usual. I'm hopeful, though the proof, as they say, will be in the pudding. The new plugs may be helping but I'm still concerned about why they were as fouled as they were.

Thoughts?

 

[TurboDawg]

Well, I got her out on the water finally this past weekend. Ran like a top; no issues at all. Ran her for a good 30 minutes or so, brought her back to the dock, and shut her down. She started right up again, and again a few minutes later. Seems like she's fixed!

Not sure what he the final culprit was. I'm guessing the plugs made the big difference, so I'll just have to wait and see if the new ones foul, and if we have the same problem later in the season.

Thanks, Doc Honda and everyone else - looking forward to a fun season on the water. I'll do my best to touch base mid-season and let you know the status (or sooner, if there's still a problem ;o)

Thanks again!
:cheers:

 

[cdoo97]

Hi, just wanted to add my experience...have a 2002 Speedster 240 and have had 2 similar hard start occurances. 2 years ago, ran the boat for several hours of cruising, playing, tubing...etc. Did several shut offs and sit...restarted fine. Then, after running a bit, shutting off...it would not start. Cranked over fine, just wouldnt fire. Very rich fuel smell from the engine compartment. Finally, hooked it to tow behind a pontoon, dragged it maybe a few hundred feet in the water...and bam! Started right up...drove great the rest of the day. Over that winter, I installed the port side temp sensor, thinking that was the issue. Took it out last year, and ran great all week..then 1 day...in the EXACT same location on the lake as the previous year...same no start issue. Same result, rich fuel smell, cranked, no start...towed a few hundred feet maybe...and started right back up!! Ran great the next few days. I never did run the blower...so just wondering if that would help my issue. Makes sense, with the excessive fuel smell...just wondering if pulling it a few hundred feet forced some fresh air into the engine compartment making it easier to start. This boat runs like new...extremely easy to start cold, very minimal smoke, no odd noises...nothing unusual. Extremely happy with my boat, except when this no start thing happens! Plugs were checked and in top shape! Next trip out, I will for sure run the blower and see if that helps. Sorry for the long post, just wanted to share my similar experience.