New here, need help with 1200 XLT

[tnerb]

I have been searching and reading these forums for a while and you guys are all great lots of great advice. My problem is that my 2004 XLT will not run below about 1,700 RPM. It just dies. If I adjust the idle speed up to around 2,000 it runs smooth, and with it down where it should be I can give it throttle and it will run but if I let off it dies.

I have rebuilt the carbs thinking that was the problem, I have gone through the fuel system everything seems to be fine. Plugs all look good, but I replaced them anyway, I have spark on all three. I have 240 hours on this ski, mostly the previous owners.

When I rebuilt the carbs I did not pull the tamper caps and clean / inspect the high and low speed screws, and I used the gold springs for the regulator pop off, leaving the pressure the same as before (rebuild kit came with shiny silver springs). The service manual did not mention removing the screws, could I have overlooked a critical step? When the carbs were put back on the engine started and died a couple of times then it started and would not shut off. ran up to about 6000-7000 RPM, I pulled the plug wires, still ran, then I pulled the choke and it shut off. I have stared it several times since and it has not done it again, could this be an air leak or isolated incident?

I am going to run a compression test after I buy a tester today. But I am running out of ideas. Any help would be greatly appreciated. Thanks,

[Hydrotoys]

Brent,
welcome to the gh forums.

First of all, when did it start having this malady?

[tnerb]

Thanks for the welcome, it started a few weeks ago and it also started bogging and seemed like it was loading up when it was run at lower speeds like 3000 - 4000 RPM. then it started having idleing problems. If I ran it hard and kept the RPM's up it ran great and the top end was still there. It has taken me a while to get the carbs rebuilt ordering parts and all.

I just got a compression tester and am going to check that now.

Thanks for the reply, I will post the compression numbers shortly.

[tnerb]

Ran the compression test and found the following low readings:

#1 - 112 lbs
#2 - 108 lbs
#3 - 115 lbs

Are these numbers too low for a 240 hour engine?

Thanks for the help

[Hydrotoys]

Most importantly, they are very close to each other. Sounds okay.

Some other ideas:

• Did you inspect the reeds while you had the carbs off? Looks for cracks etc...
• Is the catalytic converter still in one piece. They do blow apart.
• Is the pump bearings sticking? Could be dragging the engine down.
• Put a tach on there and get some accurate top end RPM numbers.
• If the spark plug wires are cracking, they can do this too...especially if you ride in salt water.
• Does it idle on the trailer but not in the water?

[tnerb]

Thanks Mark for the ideas, I am amazed by your projects, the boats you build are incredible.

I did not take out the reeds whan I pulled the carbs, I did take a few pictures (see below) that was the best way to look at them without taking them out. they look OK to me but I was not sure what I was looking for.

The cat was in one piece but I took it out replacing with the D plate and chip since I had the exhaust out.

I didn't think about the pump bearing, if they were sticking wouldn't that hurt the top end as well. Last time I had her out she ran as fast and as hard as usual but it did stop idling at the end of the day. Could I easily spin the drive shaft if I took out the plugs?

The dash tach is very hard to get an accurate reading, I don't have a tach to hook up. Any tips on an accurate tach to use?

The spark pulg wires all look good but I should check the resistance.

I have not had it in the water since the carb rebuild but am planing to put her inthe water tomorrow and check to see if the top end is still there.

Thanks again for the tips and information.

[Hydrotoys]

You should be able to turn it with the plugs out.

Hopefully some of the other folks will jump in with some ideas. Try to find the problem, and not what it does at one rpm or another. Sometimes you wouldn't expect it to run a certain way with a damaged setup.

-Check your grounds. Could be electrical.
-If the fuel pumps in the carb are leaking past the check valves, you may not maintain pressure at low rpms. The hoses taken off the carbs should suck on one hose and blow on the other, but not both on either hose. One way valves.
-Check the throttle plate alignment. If one or two of the plates aren't open while at idle, it won't idle right.

Eventually if you run out of options, pull the carbs back off and take some pics. Maybe a second set of eyes can help.

[OsideBill]

The lean engine runaway you experienced was due to the carbs not having enough fuel in them post of the rebuild. I instruct people to pull their plug wires and crank the motor several times to make sure all the fuel pumps have sufficient time to build pressure.

[OsideBill]

Thanks Mark for the ideas, I am amazed by your projects, the boats you build are incredible.

I did not take out the reeds whan I pulled the carbs, I did take a few pictures (see below) that was the best way to look at them without taking them out. they look OK to me but I was not sure what I was looking for. from the pictures they look fine generaly you look for chipped or frayed edges.

The cat was in one piece but I took it out replacing with the D plate and chip since I had the exhaust out.

I didn't think about the pump bearing, if they were sticking wouldn't that hurt the top end as well. Last time I had her out she ran as fast and as hard as usual but it did stop idling at the end of the day. Could I easily spin the drive shaft if I took out the plugs? YES

The dash tach is very hard to get an accurate reading, I don't have a tach to hook up. Any tips on an accurate tach to use? get a tiny tach or a PET tach.

The spark pulg wires all look good but I should check the resistance.

I have not had it in the water since the carb rebuild but am planing to put her inthe water tomorrow and check to see if the top end is still there.

Thanks again for the tips and information.

[zrtman]

Bad reeds on 1200's are pretty common imo. I have seen them bad with less than 50hrs on them. Whenever I do the carbs I pull the reeds to check them.

I also would have pulled the high and lows out of them. I dont see how you can clean them without doing that.

If it still has the cat in it.. could cause idle problems, but more problems on top end I would think.

As far as the runaway.. as bill stated it was probably due to empty carbs/lean condition, but I would do a couple plugs checks to double check. If its an airleak that will be expensive.