98 GTX Limited - A few issues

[CdnSeadooer]

Good day all, I have a 1998 Limited, 951 dual carb and I have a few issues I need help with.

1. When I bought my seadoo in 2015 everything worked except the speedometer. I now have a 12v low alert that beeps every 20 seconds and is very loud and annoying. My gas gauge also stopped working however my multi function gauge works just fine. I do not care about the gauges working but I would love to get rid of that beeping. The seadoo fires up first try, runs perfect and has a new battery. After a weekend of on and off use (and multiple starts) I pulled and tested the battery and it was at 100% charge. I am not certain why its giving me a 12v alert warning if the charging system is working properly.

2. When I run the seadoo with a water hose on the trailer my RPMs spike as though the water is not attached. I am afraid to do work on the seadoo outside of the lake because after 5 seconds of running my RPMs shoot up to 4-5000K. In addition, I heard the idle rpm should be 700rpm, I have played with the carb adjuster and the seadoo runs better under load when the idle is closer to 900rpm. Any thoughts?

3. When I pulled my plugs last fall one was clean and other a little more black. Is it normal for one to be a little darker or do I have a carb issue?

4. I'm replacing all my grey tempo lines next week. Any tips would be appreciated.

 

[Triorieel]

1) normal for 12v low when seadoo isn't running. Shouldn't be saying it when it is. Maybe stator or voltage regulator is on the weaker side.

2) in water your manual says rpm should be 1500rpm. Some engines will runaway at that setting on the trailer so it is advisable to set to 1400rpm in water. I like to keep mine a little bit lower at roughly 1200rpm.
When the seadoo is on the trailer, there is no resistance from the water against the impeller (impeller is always turning as long as the engine is running). This usually doubles the rpm on the trailer.

3) black like oil coated or black like soot. your carbs may need adjusted/cleaned.

4) Don't forget you have 2 different hose sizes. 1 size for fuel, one size for return/vent. make sure you clean everything including the fuel selector.
I remove all the lines, get the length of the 2 sizes and just go into local auto pars supplier MAP, NAPA, BERKLY, etc... and get automotive fuel lines and clamps.

Stainless steel clamps. I use the more expensive ones that look like the one in the picture. But that is personal preference.

 

[jjsinaz]

1) 12v Low is probably a bad rectifier and the battery is not being charged
Gas gauge is probably the F1 fuse blown or a bad float (magnets missing or full of fuel and sunk) Do a search for the F1 fuse fix

2) Idle speed should be 3000 on the trailer/1400 in the water. The 951 engine has a tendency to run away like you are describing when it is not loaded (out of the water) Air leaks around the base of the carbs can also cause that. Since you will be replacing the gray fuel lines, you also want to rebuild the carbs and you can replace the base gaskets during that process.

3) Spark plugs should both be about the same color. The cleaner one is probably running lean on that cylinder, again another reason to be doing the carb/fuel line thing. Replace the fuel selector valve too, as they tend to suck air as they age and the rubber insert inside goes bad.

Before anything else, do a compression test and see that the compression is about 130 on each hole with no less that 5 psi variance.

 

[CdnSeadooer]

1) normal for 12v low when seadoo isn't running. Shouldn't be saying it when it is. Maybe stator or voltage regulator is on the weaker side.

2) in water your manual says rpm should be 1500rpm. Some engines will runaway at that setting on the trailer so it is advisable to set to 1400rpm in water. I like to keep mine a little bit lower at roughly 1200rpm.
When the seadoo is on the trailer, there is no resistance from the water against the impeller (impeller is always turning as long as the engine is running). This usually doubles the rpm on the trailer.

3) black like oil coated or black like soot. your carbs may need adjusted/cleaned.

4) Don't forget you have 2 different hose sizes. 1 size for fuel, one size for return/vent. make sure you clean everything including the fuel selector.
I remove all the lines, get the length of the 2 sizes and just go into local auto pars supplier MAP, NAPA, BERKLY, etc... and get automotive fuel lines and clamps.

Stainless steel clamps. I use the more expensive ones that look like the one in the picture. But that is personal preference.
View attachment 40551

Thanks Triorieel for the quick reply.

1. It displays and beeps when I plug in the key. It continues when the seadoo is running and the beeping is a long 5 second beep every 20 seconds or so. Very annoying and embarrassing. Can I unplug the beeper for now and how to do that? I was curious if the low voltage came from the fuel float reading?

2. Okay great. I will bump the idle rpm back up to the 1200rpm range and see how it runs. And good to know that rpm is higher on the water hose.

3. Not oil and not dry soot.. wet soot?

4. Yes I remembered about the different sizes but almost forgot about stainless clamps!

 

[Triorieel]

If your gas is reporting empty, that causes what feels like a 10 second beep every minute.

If you have a soldering iron, it would be a perfect time to fix the fuel sending unit when you replace the grey fuel lines. It's a fuse inside that goes bad. I usually remove and jumper the internal fuse then add an external fuse. If it blows again, I only have to reach in and change the fuse.

 

[Triorieel]

The 12v thing:
I would hook up the multimeter and get the voltage with the seadoo off.
I would then start the seadoo and get the voltage with it running.

Make sure your seadoo doesn't take an excursion without you when you are doing the second part.

 

[CdnSeadooer]

Thank you both for all of the info. I will do some testing/work and post back with the results in a week or two.

 

[CdnSeadooer]

Quick update.

I replaced the Tempo lines (except for the two under the motor) and they all looked perfect. I will replace the other two in the spring. I pulled their ends to inspect and they also looked fine. To be safe I inspected a carb line I could actually reach and it too was perfect so no issues yet with gumming in my lines. It's August and I still haven't had it on the water yet so I don't want anymore downtime removing more components.

I'm going to finish the tune up and oil change this evening and have in on the water within the week!

To note, I heard that ethanol destroys the Tempo lines and I run ethanol free fuel in my PWC. My lines were in great shape.

 

[CdnSeadooer]

Now my GTX is not starting. It is cranking but not firing up. I have a full tank of gas, new plugs, etc. Could there be air in the new lines?

 

[Triorieel]

Now my GTX is not starting. It is cranking but not firing up. I have a full tank of gas, new plugs, etc. Could there be air in the new lines?

When you say it is not starting, do you mean since you did the fuel line replacement?

If so, I find the first start can take up to a minute for the fuel to be sucked to the engine. I like to look at the fuel filter to see if gas was sucked into it yet as this would be it's first step into the journey to the engine.

Some common faults I have found some people to make:
-The fuel selector is set to off.
-getting fuel return backwards with fuel supply on the carb assembly.
-forgetting to secure a clamp or hose at one of the connections.


Does the fuel reserve selector do the same thing?

 

[dean.mohr]

ALso, make sure you reconnected your spark plugs. I've done that more than once. I also forgot to fully secure my pulse line and that will keep it from starting as well.

As far as your run-away issue, I did the same thing on my 951. Found that my throttle cable was just a hair too tight and was holding the throttle open ever so slightly, causing it to immediately run to 4-5k. Double-check that, you should have a very slight amount of slack in the throttle cable @ the carbs.

If one plug looks different, definitely a carb rebuild. Also make sure your carbs are fully synced.

 

[CdnSeadooer]

Thanks for the replies. I apologize for the length but I'm trying to give some context.

The last time it ran was October 2016. I've never had an issue with it starting.. first press of a button every time even with the low 12V alert. Over the winter it was stored outdoors but I did winter prep with antifreeze, fogging oil, fuel stabilizer, etc. and brought the battery inside the house to keep warm but did NOT use a trickle charger.

Fast forward to August 17'. I replaced most of the fuel and vent lines one line at a time so I couldn't screw up the order. I did not replace the two longest lines going under the motor yet, just to the selector and one side of the filter. I changed the jet pump oil, topped up oil and gas and added new gapped plugs. I tested the battery and it read 12V+ so I put everything back together and brought it to the lake thinking it would work just fine.

It cranked a bunch but didn't kick over. Like last year it was still displaying the low 12V alert. After a bit of cranking we got hiccups and it sounded like it wanted to start and finally saw exhaust out the back. Tried for a bit more but still the same result. Cranking became sporadic and would only crank for a second then stop.. finally to the point where the battery was dead from all the cranking. We had the fuel selector on the for the main tank.

Any help would be great. Still hoping to salvage this season if possible lol.

 

[Triorieel]

When you say gapped, you gapped them or are you relying on them being gapped from the store? The gap is tight with these 0.020 - 0.024.

Is fuel making it to the fuel filter? you just repleaced lines, so it has to suck fuel back through the new ones. If there is no fuel in the filter, then it's not sucking.

Have you tried putting a bit of fuel on the intake of the carbs?

What do the spark plugs look like? wet with gas? wet with oil? wet with both? or dry?

When you have been trying to start it, have you been using choke? throttle? etc...?

 

[CdnSeadooer]

When you say gapped, you gapped them or are you relying on them being gapped from the store? The gap is tight with these 0.020 - 0.024.

I gapped them myself to 0.024. I ran the same gap last year.

Is fuel making it to the fuel filter? you just replaced lines, so it has to suck fuel back through the new ones. If there is no fuel in the filter, then it's not sucking.

Good question, I will need to check that. I still see fuel in the filter but is it new fuel being sucked in?.. that I am not sure.

Have you tried putting a bit of fuel on the intake of the carbs?

I have not, I will attempt that as well. Thanks for the tip!

What do the spark plugs look like? wet with gas? wet with oil? wet with both? or dry?

In the front cylinder (1,2?) closest to the steering wheel the plug looks clean and dry. The rear cylinder closest to the jet pump is much dirtier and looked a little wet. Last October when I stored it the front plug was also much cleaner than the rear. Possible front carb issue?

When you have been trying to start it, have you been using choke? throttle? etc...?
Yes, I used the choke and when that wasn't working (as it normally does) I began using the throttle with no luck.

 

[dean.mohr]

There are more than a few users on the forum who will tell you to rebuild your carbs, and I think I'll join them. Rebuild using genuine Mikuni parts only and reset low/high speed screws to factory settings. Again, make sure that when you reinstall the throttle line to the carbs, make sure that it has a little slack, otherwise you will cause the engine to run away (from experience!)

 

[Chester]

Is the battery fully charged and has it tested good? What is your cranking voltage? If it falls below 10.3 cranking volts, the plugs will not fire.

Chester

 

[CdnSeadooer]

Thanks all, I charged the battery and it was reading 12V+ but I never did a full test on it. We tried another battery from my gfs 2000 GTX ME (fuel injected) and it was cranking stronger but still didn't start.

I'm also thinking about the carbs needing to be rebuilt. I think the front cylinder is the issue but I will take it apart and inspect.

 

[CdnSeadooer]

Update 21 July 17.

My father in law asked his seadoo mechanic for some advice on the no start. The mechanic said there is a common issue with my model with an oil seal failing which prevents it from starting. I don't know the exact details but essentially as the seadoo sits over the winter oil weeps into the cylinders causing a collection of oil. He said to pull the plugs, cover with a rag and crank it a few times to let the oil shoot up. We did that and oil shot out.. the seadoo fired up perfectly next try!

So not exactly sure but it is running now and running better than it ever has. I think the plug/carb issue was due to my seadoo idling at 800rpm before. I have it set to run 1400-1500 idle as you guys described and it is butter smooth now. After giving the battery a good charge even the +12V alert has disappeared and is no longer beeping at me.

More to follow as I run it through some paces but it seems to be working, for now.

 

[mikidymac]

The 951 does nto have the problem of the oils seals leaking like on the 787 and smaller engines with a rotary gear. If yours is filling up with oil from sitting it can only be the check valves in the oil pump leaking or the balancer shaft seals leaking.

 

[CdnSeadooer]

I believe he means the balance shaft seals. The mechanic said it is easier to take the crank apart than to replace the seal although this was just over the phone, he never looked at it.

However, I am not sure if it is seal or not now. The seadoo has been running great with no issues until yesterday and here's why. Only twice have I completely filled the gas tank, most times I top up with a can I have sitting around. The first time was a few weeks back before it didn't run and after my ride last weekend when was done using it. Wouldn't you know it wouldn't start again yesterday when I went to ride it. Is there an issue when completely filling my seadoo it doesn't want to run? Is there suppose to be a certain amount of air in the tank?

We pulled the plugs to shoot out the oil again only this time it didn't start immediately after and this is why I am thinking a full tank issue. We charged the battery and cranked it tons and tons of times before it finally kicked over and started. Took it for a 30 minute run then shut it off to try starting it again, it started no problem.

 

[mikidymac]

Is it filling with gas or oil?

If it is oil, is it the same color as your injection oil?

The balancer gear only holds a few ounces of oil so there isn't much to leak even if the seals are bad it isn't enough to fill the cylinders up.