02 Gti Le will not take off

[morrow79]

Hey there I'm at my witts ends here.

I have a 2002 gti le with the 717 engine. It will not jump out of the water like it's susposted to. I hit the throtel and it'll take about 2 seconds sometimes longer before it revs up on to a plane. It has a new wear ring and impeller as of last year, solas 10/16 pitch. I've rebuilt the carb, ls jet 75, hs jet 167.5, 2.0 needle valve, with a pop off pressure of 38psi. Any help would be very much appreciated.

 

[Dr Honda]

Is the engine reving, and the ski isn't going... or is the engine bogging, and taking time to rev-up?

 

[morrow79]

Is the engine reving, and the ski isn't going... or is the engine bogging, and taking time to rev-up?

The engine is bogging and not getting to it's full rpm, this is also happening while getting back on throdle after a high speed run. Once it gets on plane it's good, but just getting there is the problem. I have the low speed adjust set at 1 turn out and have tried several different adjustment with 1/16 intervals ranging from 3/4 out to 1 1/4 out. High speed is at 0. It has a full tank of fresh gas, I run prenium 91 octane. The intake grate is clear of debris, securely attached and free from damage.

 

[Dr Honda]

set you needle to spec. (1 turn) then check 2 things.

1) compression

2) verify that your accel pump is squirting.

 

[morrow79]

set you needle to spec. (1 turn) then check 2 things.

1) compression

2) verify that your accel pump is squirting.

Accel pump does squirt found that out the hard way while the carb was off.

Haven't checked compression, what's the best way to check both compresion and the accel pump?

 

[morrow79]

set you needle to spec. (1 turn) then check 2 things.

1) compression

2) verify that your accel pump is squirting.

Accel pump is sqirting but engine was off and mamually activated pump arm. I have not checked compression, what proceedure do you recomend for both? Thank you

 

[Dr Honda]

You already checked the pump. Just push the arm, and watch.


You need a gauge to check the compression.

 

[morrow79]

Ok, can I get a compression tester from an auto parts store? Anything else I should check?

 

[morrow79]

I have purchased a compression tester but I'll have to wait until the weekend to check. I'll keep you posted as to what I find. Thank you for your continued help.

 

[morrow79]

okay, was able to check compression. Frount cylinder 130psi, aft 135psi. I went through a lot of tuning trying to dial in the carb but it's still now there. I pulled the carb off again and went through checking everything and cleaning everything again in hopes that maybe I missed some gunk. Still doing the same thing, however now there's a new symptom. Just past idle the boat will stall. It will hesitate then putter out quickly. I've noticed if i pull the choke out just slightly the boat will respont better out of the hole. I've swapped out the spark plugs again and gapped at .020. Still nothing. What's next?

 

[Dr Honda]

Well, unfortunately, we found your problem. That engine is getting tired, and it's not processing the fuel properly. The 720 engine should be closer to 150 PSI.

When the compression starts to drop... you get combustion gasses pushing past the rings, and that causes a drop in the vacuum. Since your ski has the single 40 mm carb... it's VERY sensitive to a loss in vacuum.

If that was my ski... I would pull the jugs, and give them a VERY LIGHT hone to break the glaze, and put in new rings. That will help restore the engine for a few more seasons.

The only other option is to send the carb to me to check it out for you. Since it's a single carb... I would only charge $35. (plus shipping back)

 

[Dr Honda]

Do you have the factory air box on this engine?

 

[morrow79]

So are you talking top end rebuild? Yes it still has the factory air box. I just paid this sucker off too.

 

[Dr Honda]

It's not really a "Top-end". I'm talking a set of rings and a few gaskets. You are looking at $50 worth of parts. A full top-end would be to bore the cyl's, and buy new pistons, wrist pins and bearings, and rings.

Your info center should tell you the engine time. Where are you at in run time?

Like I said... I'll be happy to give the carb a once over... but I don't think I will find anything.

 

[morrow79]

My friends dad helped me take it apart this last time and he's knows carbs, he found a couple minor things that I didn't have cleaned out as well as I should. What would the best thing to do to get more then a couple seasons? I'd like this boat to have a nice long life, out of the two I have the gti le is my favorite. I do not have a message center, just tac, speedo and red warning light

 

[Dr Honda]

If you want it to live a nice long life... I would do a complete top end. Right now... if you compression is that low... the lower half is starting to be cooked. Also, the hot combustion gasses are overheating the piston skirts, and killing the oil on the cyl walls. IF... you have a melt down, it will be a lot more expensive to fix after the fact.


BUT... a 2002 normally wont have enough hours on it, to have these kinds of issues. Are we 100% sure the compression gauge is good? A small leak in the hose, or if you tested, and didn't open the throttle... it will show low compression.

 

[morrow79]

I tested 3 times but, no I did not open the throttle durning the test. I'm on a learning curve here, lol. So because I didn't test correctly is that possible my compression is ok. Of course I will re-check with the throttle open as soon as I can. Does it matter if the pwc is in or out of the water for compression test. I did it with it in the water. I really appreciate all the time you're putting into this, if you're ever in Michigan I'll have a case of beer ready for ya.

So just for the sake of argument, if my compression is okay what direction would that point us in. I have noticed while adjusting my low speed screw if I screw it in completely it doesn't kill the engine like I though it would. I inspected the need and cleaned, the taper looks good, no ware marks or scratches.

Now when I purchased these boats they came with a wake board among other toys. But for the life of us trying I couldn't get my 100lb neice up on the darn thing. The pwc just didn't have enough power to get her out of the water. But with it being in there and from what else I read about the gti le 717, it's really good at pulling people up and pulling tubes. I do pull tubes but sometimes I have to cheat a little to get up on plane. With it running at peek performance I am hopeful into keeping this pwc but the majored of our summer activities are running the jet skis and pulling tubes ect. Would it be better just to get rid of this thing and upgrade to a stronger pwc, or with the repairs will the sucker be the pwc I really like. I don't need anything too fast, just strong enough to pull tubes and skiers. I have small children so I really like how stable the haul in and the assisted steering. What's your opinion?

 

[morrow79]

Ok well I rechecked the compression with wot,133 frount, 135 aft. I'm thinking top end rebuild. I'll let ya know what I find.

 

[morrow79]

update, I did a top end rebuild. Just honed the cylinders and replaced with standard rings. Cleaned everything and put back together. Compresion is now at 145 psi in both cylinders. I also replaced the fuel selector valuve. Went for a test drive today, still not jumping out of the water and there's still a hesitation just over idle. I'm thinking fuel deliver, are there screens in the fuel sending unit? I have switched from reserve to normal on and it's there is no change. Pressurization issue maybe? I have increased the adjustment on the choke to it's maximum allowiance closed and it seems to run better. Not sure if it's from more fuel being delived or increasing the vacuum pressure. I also pulled off the carb again and re-checked. All pressure checks are with in tolleranced from the manual. Still scratching my head on this one. Dr. Honda you were right on the money with the cause of the low compression, once pulling the jugs off I could see scorch marks below the rings. I was told this problem is classic crank case seal failure, but I'm not sure. Any idea's now?