New (to me ) 1997 GTI - advice after carb rebuild

[redwolf1017]

A friend of a friend had two 1997 GTIs sitting in his garage for the last couple years. He was an older gentleman and said they haven't ran in 2-3 years. He said before he put them up they had just been serviced at the shop for around a total repair bill of ~2k. He said he had no idea what all was done because they were his son's and he just footed the bill. Anyways we worked out a deal where he just wanted them out of the garage so I traded some manual labor for the GTIs.

To preface this - I've done a lot of looking around on these forums for info on what I should do first and how to do it. I work on most of my own stuff at home in my spare time, but am by no means an expert, so if I've done something wrong or out of place please just let me know, I will not be offended. Just looking for advice.

I ran compression on both units before doing anything, and both skis had approximately 143-148 in all cylinders. I was actually a little surprised at how uniform the compression was across the board. Plugs were a little rusty so I put some penetrating oil in all the cylinders and let sit overnight. One has an oil pump block off, and the other is still injection. For the rest of this post I will be speaking about the one with the oil block-off already installed as I have not started anything else on the other one as of yet.

First thing I checked after compression and besides cleaning the crap out of the ski was that the fuel lines had been replaced - which they had. It has your standard black automotive fuel line. I then drained all the gas out of the tank, pulled the carb, and installed a genuine Mikuni rebuild kit. When I rebuilt the carb it was in remarkably good shape, no corrosion or sludge or anything like that. It probably would have been fine the way it was, but since I was already that far I went ahead and installed the kit. I made sure when I installed the kit that the little plastic discs were installed with the blue side facing out, and I reused the old spring. I also set the hi/lo screws back to what they were. I honestly didn't look to see which was which, but I just wrote them down as bigger screw - 1 1/4 turn out and smaller screw 1 3/4 turn out (not sure if this is my problem or not) Also, a fun fact is that the repair shop I purchased the kit from said they remember these two units. Unfortunately they switched computer systems and no longer have the record of what was done. He did say though that he remembered water testing them and both ran great at that time.

Anyways, I did all that, mixed 5 Gal fresh gas 91 octane non ethanol with Amsoil marine premix and tried to fire it up. I tried probably 3 separate instances of being on the starter for 8-10 solid seconds and it wouldn't fire. (tried choke in and choke out). This was also with the airfilter/box off. I shot a small squirt of starting fluid and it started right up for a second then died. I then researched this and I read a couple posts about how you have to have the air filter on with air box to restrict the airflow on these engines. So I finished assembling everything and tried again. After about the third time it fired up but immediately sounded like it was going wide open throttle. I quickly shut it off (ran less then 5 seconds). Again I did some more searching on the forums and I saw a post that said it may be because the carb/fuel lines don't have enough fuel yet so its running lean and to just try to run it a little bit longer. I started it 3 more times and it was the same issue. Each time I started it I only let it run for 5-8 seconds or so. The last time I noticed if I grabbed the throttle at all it would die. I also noticed if I held the choke somewhere around halfway it would idle down and not die, but as soon as I let up on the choke it would return to what sounded like WOT.

If anyone has some advice on what to try next I would really appreciate it. Again I'm by no means an expert, and I usually don't ever work on carbed engines as I am just unfamiliar with them. I have a basic understanding but have not really ever had to adjust a carb other then on a weedeater.

Again I appreciate all the help in advance, and for all the people that have taken the time to post all the tutorials on this forum as they've helped me a lot so far.

Thanks!

 

[mikidymac]

First make sure you have the throttle cable adjusted correctly and in the correct spot. You need to verify the throttle butterfly is closing. IF it isn't this will cause the hard starting and high rpm.

If that checks out then make sure the carb base gasket is installed correctly. You should not be reusing the carb base gaskets.

Finally you will need to pull the carb back apart and verify, pop-off and leak down. Did you install a new needle and seat?

 

[redwolf1017]

First make sure you have the throttle cable adjusted correctly and in the correct spot. You need to verify the throttle butterfly is closing. IF it isn't this will cause the hard starting and high rpm.

If that checks out then make sure the carb base gasket is installed correctly. You should not be reusing the carb base gaskets.

Finally you will need to pull the carb back apart and verify, pop-off and leak down. Did you install a new needle and seat?

First make sure you have the throttle cable adjusted correctly and in the correct spot. You need to verify the throttle butterfly is closing. IF it isn't this will cause the hard starting and high rpm.

If that checks out then make sure the carb base gasket is installed correctly. You should not be reusing the carb base gaskets.

Finally you will need to pull the carb back apart and verify, pop-off and leak down. Did you install a new needle and seat?

Okay I will try all of the above. Is there a suggested amount of throttle play you should have or a way to measure it?

I did install a new base gasket when I rebuilt the carb, so hopefully it’s not that but I will double check it.

I did not install a new needle and seat. Everything looked brand new, so I figured that was part of the service that the shop did before they sat up. I just did what came in the Mikuni kit.

I’m going to try to get more work done on it either tonight or tomorrow

 

[mikidymac]

You should replace the needles and seats.

You should have 2mm play on the throttle lever at the handlebars.

 

[redwolf1017]

You should replace the needles and seats.

You should have 2mm play on the throttle lever at the handlebars.

I didn’t think about replacing the needles and seats, but I guess I’m just going to see where this gets me and go from there.

My state is now under a stay at home order and I have them both in the garage on stands. Funny thing is that after letting the one in question sit for a few days it no longer revs up when you start it up. It starts right up and sounds pretty normal to me. I’m not sure why it would’ve “fixed itself”. I guess I’m going to clean out the back flush port (dirt dobbers) and run it on the hose for just a few. That’s the only flush port on these correct? I know some older seadoos had one you had to T in in the engine bay.

I’ve started pulling the other one apart today. I guess it’s a good thing because the cable for the oil pump had a couple strands broken from rubbing on the bracket between the carb and oil pump. I think there’s supposed to be a plastic guide there but it was missing. I think I’m going to go ahead and convert it to premix like the other one just because of this and to keep them both the same.