gettin frustrated

[DnE1800twin]

ok rebuilt all four carbs over the weekend. put them on Saturday and both motors started up fine. tried to sync them but it doesnt seem to be right. they (both motors) still bog when I throttle up. The carbs look to be in sync. Is there any gauge that would tell me. I used to work on carberated motorcycles and I have a carb syncing tool that works off vacuum. Is there such a tool for these carbs? Will my vacuum tool work? what a pain in the arse. Is there anyone in the gainesville area that can help (besides dealer and their prices).

 

[seadoosnipe]

Accelerator pump?

Have you verified that your accelerator pump is working correctly on each of the backsides of the PTO carb?

If your getting bogging only while throttling up and they both sound and run good at mid range and over, then I'd check them. They are notorious for gumming up the check valves.....

No, your vacuum sync would not work. It could be used but you don't have any ports to connect to draw off the vacuum.

Syncing is really simple on this model. With everything removed so you can get to them, run the thumb stop on the idle of the MAG carb off enough that it is no longer touching the stop plate. Then, disconnect your sync bar across the carbs. At this point, you should be at closed on both carbs. You should verify that both throttle plates are closed. This would be a good time to check your accelerator pump too by rolling the cam on the PTO carb open while watching the small brass tube that has that small fuel line on it (should be around the 2 o'clock position). Try to look into both carbs, one squirt at a time because you will not have a huge supply of fuel to play with while the engine is shut down.

Then, take your sync bar and hold it up to the ball of the carb you disconnect from to feel if it feels like it is even to the bar. If you have to move that bar to connect to the carb you disconnected from, then your likely out of sync. The proper way is to measure it from each button head of the synch bar to the etched line in the bar.

To ensure your in sync, just look into each carb as you roll your connected carbs back at 1/4, 1/2, 3/4 and wide open to see if they are even. That's it. Not nearly as involved as the needle and plunger on a bowl type Mikuni on a motorcycle.:cheers:

 

[DnE1800twin]

I disconnected the sync bar just as you said. made sure both butterflys were closed and adjusted the bar to fit.
this accelorator pump... you say look inside at the brass tube. I know what your talking about. this tube should spray a bit of fuel when I turn the cam on the pto carb??
I'm goin out to check that.
as far as the vacuum tool... I didnt think it would work for lack of vacuum connection. it was a thought tho..lol

 

[seadoosnipe]

idle?

O.K....that's cool, but you did have the idle thumb screw backed off the MAG carb?

I'm at work so right now, I'll come back and check your repost in a bit....

 

[DnE1800twin]

well I did now...lol
I have the PTO carb off again. I didnt notice any fuel coming from the brass tube so Ill take apart the pump and check for GOOOOOOOO...
Ill repeat on Starboard motor.
Thanks for your help. Sucks your at work and im playing with the boat..lol
It is nice to have a few days off every now and then.

 

[seadoosnipe]

coolll.....

I should have mentioned that its not in your pump. It's the check balls either after the pump or just before the carbs....

Oh well, if you take the diaphragm off, you'll gain a bunch of experience. I just hope you don't tear it. That sucker costs about $200 bucks to replace. You have to buy the entire pump.

I finally saw a place last year that sold just the diaphragm but didn't bookmark it.........

Good luck!......:cheers:

 

[DnE1800twin]

well chock it up to experience> i took off the diaphram (no tears) cleaned it out now I can blow thru it no problem. put the carbs back on and now the motor wont start. The mag carb is drippin fuel (from small venturi inside carb) but not the pto carb. both plugs have fuel on them and spark but no start. UGH!!! it started and idled ok yesterday but today the starboard motor wont start.

gonna take off the pto carb and clean out the acc.pump on the port motor. it runs good now but does bog when I throttle up. (which why I first posted this thread.)

 

[seadoosnipe]

Pop off?

Did you do a pop off test? The fuel is likely coming by the needle valve, which means your pop off is bad or your needle valve is sticking.

Turn off the fuel. Then, try to start. Once you get a start, turn the fuel back on. You can at least here it run but will have to correct your needle valve problem....

 

[DnE1800twin]

k ill try that.
I didnt do a pop off test.
A. no popoff tester.
B. Ive been reading that it wasnt necessary if I reused the springs when I rebuilt the carb

 

[seadoosnipe]

Pop-off....

Most of the times it isn't. You may just have a needle valve that lifted.

The springs aren't the only thing that affects your pop-off. The lever that attaches to the spring needs to be flush or bent upwards no more than 1mm.

Thats prob what happened. You got your lever up too much....:cheers:

 

[DnE1800twin]

yep your prolly right. and it puttin too much fuel into the cylinder. i'll take apart AGAIN and check that tang the needle hangs from.

 

[seadoosnipe]

Prob it....

I'll put money on it, if your springs are still good. I'd only pull the PTO though, since the MAG is not leaking by.

 

[timmyboy76]

When rebuilding the carbs, did you use "mikuni" kit, or gasket technology...if the aftermarket, i'd put money on its lifting the needle. Bend the "tang" down, to where its flush with the inner body of carb....if/when you get it fired, and still cant eleiminate the "bog", YOU CAN ALWAYS "DUMP" THE XCELLERATOR PUMP AND FATTEN UP THE Jets a bit...sorry for capitals.

Just finished, work'n on boat,(99 challenger 1800, 2-110'z)and his carbs were junk...saltwater sit'n inside for who knoew how long, SO..got a few carbs from ebay, with non xcellerator pump/fittings, so, jetted them accordingly, and now this boat/motors sound/respond better than xcellerators...i think.

 

[DnE1800twin]

thanks for all the help.
I think I'll work on it some more tomorrow.

 

[DnE1800twin]

well its been about 2 weeks since ive worked on the challenger.
I took all 4 carbs off again today. checked the needles and the tangs they hang from. I think they are all ok.
The motors still run awesome at idle but when I throttle up they bog. both motors are doin the same thing. I'm sure that the carbs are synced pretty darn close. I havent messed with the low speed screws yet. Is there a starting point for these screws?

 

[timmyboy76]

1-1/2 on the lows, 0 on the highs.

That yr/mdl of boat, they found that going to 67.5 on the pilots, worked way better, no hesitation, but that aint the problem for now.....?, did you replace the springs inside the carbs, when rebuilding them.

 

[DnE1800twin]

ok ill try that setting. Ill be working on the boat again today.
I didnt change the springs. Ive read in several other posts that I didnt have to.

 

[DnE1800twin]

ok I think I should rename this thread to "gettin closer". lol
I tried something after checking that the low speed screws were 1-1/2. they werent but are now. Anyway I tried putting the motors in gear. forward and reverse. while in gear the motors reved up without bogging. but in nuetral they both still bog. hmmmm any ideas??
just fyi...the boat is on the trailer with the wash down hose hooked up so theres no real load on the impellers.

 

[DnE1800twin]

oh and the accelerator pumps are working fine so ill stick with the jets are in it for now