2002 GTX 4-TEC

[qualityexteriors_wi@yahoo]

Hello,
I just purchased a 2002 GTX 4-Tec. It has only 70 hours and not a scratch on it.
It only reaches about 6500 RPM and maybe 41MPH. Previous owner had said the wear ring had been replaced. I have not checked clearance yet.
When the DES is plugged in, it beeps twice but keeps beeping twice every five seconds or so.
I'm familiar with the 2-strokes but this is my first 4-Tec.
Looking for advice on where to start. TIA

 

[MacSeaDoo]

Is there anything coming up on the cluster?

I don't trust a word any seller says.

Not reaching top speed is going to one or both of 2 things.

1.. Is your machine able to make the HP is was designed to make.
2.. Is your jet pump able to transfer that power to the water as it was designed to do.

Put the machine in the trailer, crawl under and get some photos up in the intake grate of the impeller and wear ring. Post it here and we can advise

If you are comfortable changing spark plugs, change them.

If not, take them to someone who can change them. Ask to have them marked from where the old ones came from which cyl as it is helpful in understanding what is happening in the combustion chamber.

 

[qualityexteriors_wi@yahoo]

Thank you for the quick reply. I'm comfortable doing almost anything on the ski. I'll change the plugs and get pics of intake, impeller and wear ring and post ASAP.

 

[qualityexteriors_wi@yahoo]

Also, what is considered "level" for checking the oil? The boat is on a lift and the bottom of the hull is slightly raised. Is floating considered level?
On the lift, the oil reads over max on the dip stick. Obviously, if it is, that's not good and could cause the low RPM.

 

[qualityexteriors_wi@yahoo]

Impeller and wear ring pics.

Oil level pretty much the same floating and on lift. It is filled over MAX

 

[frpole]

I have the same machine as 2002 was the first year of the 4-Tec 1503 155hp engine (Naturally Aspirated). Your top speed is very close to what I get as well, but I rev around 7500RPM when I'm at full throttle. I think MacSeaDoo is leading you to check the condition of the cylinders first by viewing the plugs, then putting in fresh ones, and in-between - if you're up to it - doing a simple compression test of each. The oil overfill is NOT good and I would suck some out with a vacuum pump to get right in between the dipstick markings. If you dont have the manual for this machine I think you can still download it from seadoo.com under the owners section, or if I recall you can download it from this forum.

 

[qualityexteriors_wi@yahoo]

Thank you. Yes, I'll get the oil to the proper level before running the machine again.

 

[qualityexteriors_wi@yahoo]

I have the same machine as 2002 was the first year of the 4-Tec 1503 155hp engine (Naturally Aspirated). Your top speed is very close to what I get as well, but I rev around 7500RPM when I'm at full throttle. I think MacSeaDoo is leading you to check the condition of the cylinders first by viewing the plugs, then putting in fresh ones, and in-between - if you're up to it - doing a simple compression test of each. The oil overfill is NOT good and I would suck some out with a vacuum pump to get right in between the dipstick markings. If you dont have the manual for this machine I think you can still download it from seadoo.com under the owners section, or if I recall you can download it from this forum.

Are the constant "two beeps" normal? All my 2-stroke sea-doos beeped twice when attaching the DESS lanyard. This one beeps twice but keeps beeping twice every 3 seconds or so with lanyard in and engine not running.

 

[MacSeaDoo]

From what I understand, your machine should be able to hit 55+ MPH. (55 to 58 MPH)

Looking at the pictures, the wear ring appears to have some marks in. The impeller looks ok but there is some leading-edge damage that can affect things like top speed. Also, the ring impeller clearance looks excessive to me but it is difficult to make this out in some of these photos.

I would change the plugs, and see if that changes anything.

 

[qualityexteriors_wi@yahoo]

From what I understand, your machine should be able to hit 55+ MPH. (55 to 58 MPH)

Looking at the pictures, the wear ring appears to have some marks in. The impeller looks ok but there is some leading-edge damage that can affect things like top speed. Also, the ring impeller clearance looks excessive to me but it is difficult to make this out in some of these photos.

I would change the plugs, and see if that changes anything

Ok, thank you. I will change the plugs. I will check wear ring/impeller clearance as well, but would that limit the RPM to 6500? From what I've read, I thought it should run closer to 7500RPM

 

[qualityexteriors_wi@yahoo]

I pulled the plugs to inspect (I don't have new ones but will get some). These look new, all look the same except rear two (cyl 1&2) have a chalky substance on the ground electrode

 

[qualityexteriors_wi@yahoo]

I pulled the plugs to inspect (I don't have new ones but will get them ASAP). Look new, all look the same except rear two (1&2)

 

[qualityexteriors_wi@yahoo]

Did a compression test. All cylinders are over 100 on first stroke. Up to 175 by the 3rd-4th. All hold that compression.
If I peg it off of idle (in the lake on a test ride) rpm go right to 7500. Once I'm on plane (takes 2 seconds or so) rpm drop to 6500 and stay right there.
Is it possible the wrong pitch impeller is in this thing?

 

[MacSeaDoo]

The plugs do look new as they have zero browning on the ceramic.

The white residue is often a sign of running lean. Could be issues with those injectors.

You can easily pull the rail on the machine and put the injectors into 3 glass jars. Turn it over to see the spray pattern and qty.

It is possible the impeller is not stock. Hard to tell without pulling the pump off.

 

[qualityexteriors_wi@yahoo]

Could the Opas be sticking down into the water & slowing it down? Strange how it'll hit 7500 right away but then not get over 6500 when on plane

 

[BGS]

Could this be max speed limit kicking in ? rpm go right to 7500. Once I'm on plane (takes 2 seconds or so) rpm drop to 6500

 

[ski-d00]

remove oil to half way between the marks on dipstick, change plugs, report back. You should be hitting 60mph on the gauge.

 

[qualityexteriors_wi@yahoo]

The plugs do look new as they have zero browning on the ceramic.

The white residue is often a sign of running lean. Could be issues with those injectors.

You can easily pull the rail on the machine and put the injectors into 3 glass jars. Turn it over to see the spray pattern and qty.

It is possible the impeller is not stock. Hard to tell without pulling the pump off.

Hi Mac, I know this an old thread but I just began messing with this ski again. New Solas 11/19 impeller with stainless wear ring. New plugs and coils. Fresh oil change and level is centered between marks. Still only turns 6500 RPM but it does run about 5mph faster (47 on gps). Will rev to the rev limiter on the trailer and in reverse when in the water. Any other ideas?

 

[ski-d00]

You don't ever want to go full throttle in reverse. It can rip the reverse bucket right off, only slightly above idle in reverse. You shouldn't rev it to full throttle not under load which is hard on your engine and cause damage and basically tells you nothing. Have you done a leak down test? This is a much better engine health test than a compression test. Press set 5 times to check for active codes. Beeping with the key on and not running is a normal reminder that you left the key on. Does it idle at 1800 without surging? Does it accelerate without cavitation? Is your throttle body fully opening at full throttle?

 

[qualityexteriors_wi@yahoo]

Thank you for the reply.
Understood.
No active codes. Accelerates without cavitation. Throttle body fully open.

 

[ski-d00]

What does the injector spray pattern look like? What is your fuel pressure?
Doing a leak down test will confirm that your engine can make enough HP.

 

[mkov608]

I had 2 of these skis. One of them had the same problem you mention (only 43 hours on the skis when I picked them up in 2012); it turned out (with Ski-Doo's help), to be a bad J-pipe. I had an exhaust leak leaking into the hull, so the engine was sucking in exhaust gasses. That kinda kills performance. Ski-Doo sold me a used J-pipe, I swapped it out, and it was like a different ski after.

I used Sea-Foam spray to find the leak. You could also use a thermal imager. Look around the flex joint of the j-pipe where it attaches to the exhaust manifold. A few years later, the 2d j-pipe also failed; I found a replacement on Ebay. Funny thing is, the other ski never had a j-pipe issue