2018 Seadoo GTX 155 (75Hrs) Only Goes 40 Mph

[allanjoburns]

2018 GTX 155 (75Hrs)
- New Battery
- New Wear Ring
- New Spark Plugs (NGK 4339 - DCPR8E)
- New BRP Oil & Filter (ran 30 sec, off 30 sec, little over halfway on the dip stick)
- New Key Programed - I had the only key(Green Learner) programed to be the normal key (says "normal key" at startup now)

Speed Issue
Took the ski out for a test run and warmed it up by idling out of the loading/unloading area for 2-4 minutes. Cruised around at 15-20 mph for a few minutes and everything is running great. The water was glass, so I decided to go WOT in sport mode to see what the top speed was (should be around 55mph). I only hit 40mph moving with the current and 37mph against the current. I did a few more pulls to check for cavitation, there was none (very responsive in sport mode). Went back to the dock to trailer the ski and it idles and runs amazing with no back firing, missing or anything.

Items I've Checked
- IBR Gate/Bucket functions (up and down) and is good.
- Intake Grate & Pump - Checked for any foreign objects. Impeller looked bent from previous owner picking up a rock/stick (New Solas SR-CD-11/18A arriving Saturday)
- Pump Bearing - Impeller spun freely and smoothly when I check before removing it.
- Wear Ring - Wear ring installation was good and the inside surface is snug to the impeller.
- Pulled the spark plugs and they all look good (image below)
- Carbon Seal - Tried pulling it back to see if it's weak and maybe creating cavitation, I maybe moved it 1/32 of an inch with my hands so it seems solid.
- A little bit of water in the hull (16oz or less) after the ride.
- Fuel - A little over 1/4 tank of clear (non-ethanol) from the previous owner.
- Compression - Pretty even across all 3 with a cold engine, no lube with an uncalibrated gauge. (+/- 1 or 2 lbs)

Items I need to check
- RPM at full speed should be 7400, just need to verify this
- Spark (Inline spark tester will be here Saturday)
- Fuel Pressure - I will test the fuel if I don't get full RPM after the new impeller install and spark check. What should the pressure be?
- Injector Spray - I will test if the items above fail to gain MPH.

Anyone have any other suggestion on what could be the issue or have I basically covered everything?

Note: I plan on testing it this weekend rain/shine after I install the new Impeller and use the inline spark checker. I will follow-up after the test!

3/26 Update - Installed the new impeller and she now goes 55mph! Issue resolved! I'll save the extra plugs and the inline spark tester for future trouble shooting!

 

[skiasylum]

Bad coil pack will cause your issue. They can fire and work well at low RPM but not fire hard enough at high RPM causing that reduction in WOT RPM. If you have three new ones laying around? Dirty injectors also.

 

[ski-d00]

Your trailing edges of your impeller are very bent up which is what gives the top end speed. I'll bet it runs great with a new impeller.

 

[MacSeaDoo]

Is that a stock original impeller as I guess I have not seen to many of them because it doesn't look right. It looks like there was some leading edge damage and someone just cut them off?

 

[clegg]

Good read. I need to check my impeller on my 2018 GTI155. It has the same issue. Has about 90 hrs, I thought that the impeller would still be good.

 

[ski-d00]

That is the stock impeller. Leading edge may have been filed a little but that's definitely the stock profile. It got something stuck like a rock or stick between the vanes and the trailing edges of the impeller and then probably spit it out. It only takes a couple seconds to do damage and basically ruin the impeller.

 

[skiasylum]

You can see a pretty deep gouge in the wear ring.

 

[allanjoburns]

You can see a pretty deep gouge in the wear ring.

Thats just a light scrape, from installing and removing the impeller. I ran my finger over it and its not a gouge, just the lighting I guess haha.

 

[allanjoburns]

Good read. I need to check my impeller on my 2018 GTI155. It has the same issue. Has about 90 hrs, I thought that the impeller would still be good.

Yea, I was hoping to create a 1 stop shop for people with similar issues since I read a bunch about it. Thanks for the compliment and let me know if I need to update the original post to share more information upfront!

 

[allanjoburns]

Your trailing edges of your impeller are very bent up which is what gives the top end speed. I'll bet it runs great with a new impeller.

Replacing the impeller did the job, thanks for this feedback!

 

[allanjoburns]

Good read. I need to check my impeller on my 2018 GTI155. It has the same issue. Has about 90 hrs, I thought that the impeller would still be good.

If your replacing the impeller, you might as well replace the wear ring and kill 2 birds with one stone to eliminate any other potential issues aside from the pump itself

 

[LakesideRec]

OP mentions they replaced the wear ring. If there was a reason to replace the wear ring, then the impeller undoubtedly took some damage too.
It only takes a slight ding to destroy the top end performance of the impeller. Filing it smooth again might make it work OK, but you won't ever get back top factory performance once the edges get ragged or the balance is not perfect, or there is a slight wrinkle or off-pitch bend in a blade.

Looking at the photo of the impeller, was pretty beat up. I am kind of surprised he was able to get 40 mph out of it.

 

[jakec50]

New member, 2005 GTX 155 64 hours. Ski cranks an runs ok. Will not get over 6000 RPM then after 10 mins spits and sputter barely running but never dies. Maybe its going into limp mode with no warning beeps? New plugs and coils. Suggestions?

 

[jbnorthwest]

I'm going through same troubleshooting process on a 2018 Wake 155. runs great, quick acceleration but won't go over 45. Wear ring was thrashed so I assumed that was the problem but to my surprise a new stainless ring made at best 1-2 mph difference. Prop isn't like chewed up but it's worn, so I guess that's the next step. Going to install a Solas this weekend

 

[clegg]

Same issue here. 2018 GTI 155. Replaced the wear ring. It wasn't thrashed but had some decent wear. The impeller looked fine. I also checked the part number on the impeller, has the correct seadoo impeller.
Maybe gained 2 mph. Lucky to get 45mph.

 

[oldsurfcat]

Same issue here. In April '23 purchased a beautiful 2018 GTI 155 with only 14 hours on the clock. Starts and accelerates superbly up to a hard limit of exactly 6040 RPM and roughly 42 MPH, depending on offshore conditions. Have gone threw a slew of steps and checks, including cluster reflash to eliminate possibility of 99 HP/rental limit configuration. I will be reflashing the mapping next week. Once I do an offshore test I'll do a summary here of the results, process to date, and list the professional help I've received at each stage. I'm hoping to report "resolved."

 

[jbnorthwest]

Same issue here. In April '23 purchased a beautiful 2018 GTI 155 with only 14 hours on the clock. Starts and accelerates superbly up to a hard limit of exactly 6040 RPM and roughly 42 MPH, depending on offshore conditions. Have gone threw a slew of steps and checks, including cluster reflash to eliminate possibility of 99 HP/rental limit configuration. I will be reflashing the mapping next week. Once I do an offshore test I'll do a summary here of the results, process to date, and list the professional help I've received at each stage. I'm hoping to report "resolved."

I’m going to try new plugs next and then maybe aftermarket coil packs as a test. They probably suck but I figure it’s a relatively inexpensive test and I can buy OEM if i identify a weak one. My wife and I went out last weekend and the little spark 90hp with a new Solas impeller hit 50mph couldn’t believe it. And that’s with my big ass at 230lbs. Plus the spark at idle sounds like it’s about to throw a rod , coughing and chugging. Meanwhile the Wake 155 is plodding along at 43 even with my wife at half my weight !

 

[NEZZA]

Check your inlet manifold. Mine split replaced it with a brace and all is well now

 

[oldsurfcat]

Ok. I've seen countless posts across multiple forums about 2018/2019 GTIs limited to 40 MPH, but have never read a consistent root cause and solution. I'm going to build on my earlier post to lay out what I've done based on professional support, not yet from a dealer tech.

I'm hoping someone has concrete knowledge of the issue, root cause, and most likely solution. I do have the CandooPro tool to provide me with system diagnostic insights. To recap my vehicle and issue:

• 2018 GTI SE 155, 14 hours on clock at purchase, which was late April 2023.
• Runs great; tons of power up to a speed limit of 41.7 - 41.9 MPH as verified by independent GPS, and duplicated by the cluster GPS speedo. RPM is a steady 6040 when in the water at that speed.
• Plugs pulled and changed, but were perfect. Compression tested, and were 168 PSI on the button for each cylinder with my gauge. Impeller has extremely minor imperfections, but nothing that could cause a 13 MPH reduction is the typical 55 MPH top end reported for smooth water.
• Removed the cluster, sent into a professional to reflash to the correct Non-Rental file (99HP limit) calibration using BUDS2. No change.
• Hired a service to remotely diagnose the systems via BUDS2. Cluster had yellow status and could not be accessed to read configuration. Some modules were flagged for 130 model. vice 155. All modules were set to 155 model.
• Service reflashed/overwrote the ignition/fuel mapping to a light performance tune. Between changes made in BUDS and performance tune, no change in speed.
• When the ski it jumps out of the water in ocean conditions, the engine revs up to the new 8000+ limit. Once it lands it's again limited to the water speed for conditions, not exceeding 42 MPH. My speed tests were all conducted in a large harbor, outside of the no-wake zone, with smooth conditions.
• I was told by one of the professionals that BRP has a known issue whereby on some 2018/2019 GTIs they cannot convert the system out of Rental mode. They're working on a fix.
• I was told by another Seadoo master mechanic (not at the dealer) that the 99HP calibration feature must be revised in both the cluster and the ECU. Of course, if it can't be accessed when in the system with BUDS2, one cannot confirm that it has been updated. In fact, I question the yellow icon status.

I one hundred percent believe that the consistency of the speed limitation eliminates any mechanical issue as a root cause. Plus none of my other findings support anything less than a perfect condition power train.

Does anyone know exactly how the Rental mode calibration files limit craft speed? It could be throttle response limit or GPS. I don't believe anything changes the mapping. For instance ECO and Touring modes are throttle response changes implemented in conjunction with a single mapping profile, based on information provided by one of the professionals.

Barring any new information, or going to a dealer, which I may do at this point, my inclination is to purchase a new BRP, not Chinese, cluster, have it flashed and married to my ECU (which I can also do with CandooPro).

What do you all think?

 

[jbnorthwest]

Ok. I've seen countless posts across multiple forums about 2018/2019 GTIs limited to 40 MPH, but have never read a consistent root cause and solution. I'm going to build on my earlier post to lay out what I've done based on professional support, not yet from a dealer tech.

I'm hoping someone has concrete knowledge of the issue, root cause, and most likely solution. I do have the CandooPro tool to provide me with system diagnostic insights. To recap my vehicle and issue:

• 2018 GTI SE 155, 14 hours on clock at purchase, which was late April 2023.
• Runs great; tons of power up to a speed limit of 41.7 - 41.9 MPH as verified by independent GPS, and duplicated by the cluster GPS speedo. RPM is a steady 6040 when in the water at that speed.
• Plugs pulled and changed, but were perfect. Compression tested, and were 168 PSI on the button for each cylinder with my gauge. Impeller has extremely minor imperfections, but nothing that could cause a 13 MPH reduction is the typical 55 MPH top end reported for smooth water.
• Removed the cluster, sent into a professional to reflash to the correct Non-Rental file (99HP limit) calibration using BUDS2. No change.
• Hired a service to remotely diagnose the systems via BUDS2. Cluster had yellow status and could not be accessed to read configuration. Some modules were flagged for 130 model. vice 155. All modules were set to 155 model.
• Service reflashed/overwrote the ignition/fuel mapping to a light performance tune. Between changes made in BUDS and performance tune, no change in speed.
• When the ski it jumps out of the water in ocean conditions, the engine revs up to the new 8000+ limit. Once it lands it's again limited to the water speed for conditions, not exceeding 42 MPH. My speed tests were all conducted in a large harbor, outside of the no-wake zone, with smooth conditions.
• I was told by one of the professionals that BRP has a known issue whereby on some 2018/2019 GTIs they cannot convert the system out of Rental mode. They're working on a fix.
• I was told by another Seadoo master mechanic (not at the dealer) that the 99HP calibration feature must be revised in both the cluster and the ECU. Of course, if it can't be accessed when in the system with BUDS2, one cannot confirm that it has been updated. In fact, I question the yellow icon status.

I one hundred percent believe that the consistency of the speed limitation eliminates any mechanical issue as a root cause. Plus none of my other findings support anything less than a perfect condition power train.

Does anyone know exactly how the Rental mode calibration files limit craft speed? It could be throttle response limit or GPS. I don't believe anything changes the mapping. For instance ECO and Touring modes are throttle response changes implemented in conjunction with a single mapping profile, based on information provided by one of the professionals.

Barring any new information, or going to a dealer, which I may do at this point, my inclination is to purchase a new BRP, not Chinese, cluster, have it flashed and married to my ECU (which I can also do with CandooPro).

What do you all think?

FWIW mine goes over 42mph depending on current and conditions, fastest was 47. So at least for me it’s not a hard set 42mph limit

 

[oldsurfcat]

FWIW mine goes over 42mph depending on current and conditions, fastest was 47. So at least for me it’s not a hard set 42mph limit

Thanks for the data point.

 

[oldsurfcat]

JbNorthwest: Now I'm wondering about the impeller. Mine has light dings in the leading edges and I can't see the condition of the trailing edges. A SR-CD-11/19 is a relatively cheap R/R. Did you changeout to a Solas yet? It's counter intuitive to me why the engine revs to 8000 RPM when it jumps out of the water, but only pulls 6040 RPM under full load in the water. I see it resolved the issue for allanjoburns

 

[PWC Noob]

Hi, new member here. I have the same speed issue with my 2014 SE 130 GTI, it only gets to 40 mph (used to easily hit 55) and it is not running smooth. I know I need a new impeller, my son sucked a few rocks the first 5 minutes on the lake this summer! The impeller condition looks almost identical to the OP's. I don't want to take it apart yet until the new parts are here but we want to go out a couple of times before I can get around to it. My question is if it could cause serious damage if I continue to use the machine with the damaged impeller for another 2 or 3 hours. Thank you in advance for your help!

 

[Jeff Berner]

2018 GTX 155 (75Hrs)
- New Battery
- New Wear Ring
- New Spark Plugs (NGK 4339 - DCPR8E)
- New BRP Oil & Filter (ran 30 sec, off 30 sec, little over halfway on the dip stick)
- New Key Programed - I had the only key(Green Learner) programed to be the normal key (says "normal key" at startup now)

Speed Issue
Took the ski out for a test run and warmed it up by idling out of the loading/unloading area for 2-4 minutes. Cruised around at 15-20 mph for a few minutes and everything is running great. The water was glass, so I decided to go WOT in sport mode to see what the top speed was (should be around 55mph). I only hit 40mph moving with the current and 37mph against the current. I did a few more pulls to check for cavitation, there was none (very responsive in sport mode). Went back to the dock to trailer the ski and it idles and runs amazing with no back firing, missing or anything.

Items I've Checked
- IBR Gate/Bucket functions (up and down) and is good.
- Intake Grate & Pump - Checked for any foreign objects. Impeller looked bent from previous owner picking up a rock/stick (New Solas SR-CD-11/18A arriving Saturday)
- Pump Bearing - Impeller spun freely and smoothly when I check before removing it.
- Wear Ring - Wear ring installation was good and the inside surface is snug to the impeller.
- Pulled the spark plugs and they all look good (image below)
- Carbon Seal - Tried pulling it back to see if it's weak and maybe creating cavitation, I maybe moved it 1/32 of an inch with my hands so it seems solid.
- A little bit of water in the hull (16oz or less) after the ride.
- Fuel - A little over 1/4 tank of clear (non-ethanol) from the previous owner.
- Compression - Pretty even across all 3 with a cold engine, no lube with an uncalibrated gauge. (+/- 1 or 2 lbs)

Items I need to check
- RPM at full speed should be 7400, just need to verify this
- Spark (Inline spark tester will be here Saturday)
- Fuel Pressure - I will test the fuel if I don't get full RPM after the new impeller install and spark check. What should the pressure be?
- Injector Spray - I will test if the items above fail to gain MPH.

Anyone have any other suggestion on what could be the issue or have I basically covered everything?

Note: I plan on testing it this weekend rain/shine after I install the new Impeller and use the inline spark checker. I will follow-up after the test!

3/26 Update - Installed the new impeller and she now goes 55mph! Issue resolved! I'll save the extra plugs and the inline spark tester for future trouble shooting!

Did you get it fixed, I got a2001di does 64

 

[oldsurfcat]

All,
Back to my June 11 post on 2018 GTI SE155 that doesn't exceed 42 MPH on the SoCal ocean. My last ditch effort was to install a new impeller/wear ring to hopefully resolve the problem. I was finally able to do so this week. There was definitely a significant groove/small tunnel in the wear ring and chips on the impeller. With the Solas 10/18A I only gained 1.5 MPH. All readings are via dash and two GARMIN GPS's.

Since purchasing used from the dealer in March, I've reflashed the cluster (Thank you Dennis at Candoo for your tireless help and countless go-backs), reflashed the ECU (Thank you Martin at Reliable Tuning for your help and expert advice), checked compression (excellent), spark (new plugs, didn't scope, but no issues showing with Candoo diagnostics). I have not done any fuel path checks but given the relative good performance out of the hole and up to top speed I'm not convince there's an issue there. I even tried a straight-through exhaust for fun at the cost of $25 and Worx WR243 intake grate for shits and grins.

I'm out of patience to check anything else and recently fell into an unexpected deal on a 2018 Kawi 310LX.

I'll sell it as-is, in beautiful physical condition and generally excellent running, and let the new owner figure out why 44 MPH is the best I can do on the ocean.

Now having ridden the Kawi and GTI in medium to medum plus ocean chop conditions, it might be my imagination but the Seadoo seems every bit as capable in the chop and swells, and airborne stability, as the Kawi at speed, perhaps even superior. I know it's not supposed to even compete, but on my Catalina runs back to the mainland with buds on Waverunner VX models and my friend on the 310LX that I now own, the Seadoo not only held its own but seemed to consistently run 1/2 mile ahead or more with ease. I'm a newbie, very old, wretched, and slow with no skills - they are very experienced riders, especially the Kawi rider. I really respect how this hull performs. So long Seadoo!!