hard start - 1999 challenger - newbie

[ANDYstepan]

Hi all - great forum. I just found it this morning.

Here's my problem- I have a 1999 challenger - w/ 2- 110hp Bombardier Twin Rotax Engines. I just bought it .....it's in perfect condition - not a scratch on it. I purchased it from an older guy - he's drove it but probably only 20 hours a summer.

When I bought it he said, "it's a little cold blooded - but once she gets going it's no problem."

So this weekend we took it out (it was in the 70s) it look about 5 min to start each motor - and then once they did start we took it around the lake and they were cutting out....we were around 3000rpm. Finally after about 20 min we just mashed it and they sputtered for a second and really took off.....and continued to run great on 3 more passes around the lake. The boat is like a rocket....errr....once it's warmed up.

here's my question -

1)it look 5 min to start each motor.....it was almost acting like it wasn't getting gas - is there a central (1) fuel pump or does each motor have it's own pump
2)are these boats notoriously hard starters or cold blooded?
3)why would all of a sudden it run fine?

thoughts? thanks for any help you can provide.
Andy

 

[seadoo-owner]

I have a 99 Challenger 2 x 110hp 787's same as yours and yes 1 engine is hard to start compared to the other side
it is a matter of finding the choke setting your engine likes I have found from experimenting that pumping the throttle forward a couple of times( no more that a couple ) first before cranking is a great help (the boats have a accelaration pump on the side of the carbs that the skis dont ) and this squirts a little stream of fuel into carbs as you push throttle forwards
then apply choke and crank her over

secondly you may want to service engines and carbs /fuel filters
also could be stale gas if she has sat for a while

def fuel related as you say once warmed up /all of a sudden she takes off and runs a treat

so new fuel /filters and spark plugs /engine service and you will have a great boat ready for next season

Enjoy :cheers:

 

[seadoo-owner]

Adding to my previous reply
there are 2 seperate fuel pumps one on each engine so no the start issue is not due to A fuel pump
there are also 2 inline fuel filters
looking at the front centre of the engine compatment (just under the ski mast is the connections to/from the fuel tank ) and running to each fuel pump mounted on the engine block
there are also fuel filters in each of the carbs

 

[Nate Surveyor]

OK, I don't have your boat, or your motors, I just have the old 717 motor, with a single carb. Yours is nicer than mine.

However, with what you describe, here is some "Fer what it is worth" commentary.

IF you still have the old gray fuel lines, change them ASAP. They deteriorate into the fuel, and clog the fuel filters, and carb. This will plague you until you replace them. (See sea doo snipes sticky on bogging)

After that, clean all filters, and the carbs, and carb filters.

And, Mine has the accelerator pump as yous does too.


So, here's my recipe for you:

Pull it to the lake, and after putting it in the water, but still tied securely to the trailer, use a can of spray silicone lube, and spray a 3-4 second burst down the fogging hole, in the top of the spark arrestor. (Looks like an air cleaner, and has a small rubber plug in it) Remove the rubber plug, and spray the silicone down that hole.

Hit starter. Allow to idle for maybe a minute. If it dies, before that, spray it again, and restart. Do this several times, until it remains running.


The accelerator pumps won't work, when it has no fuel in the carbs. That is why you use silicone spray to start up at first. IF you over doo the accelerator pump thing, you may flood it. Go easy.

My concern for the method you are using is:
1.) you provide unnecessary wear to the starters.
2.) you may run the batts down. And, be dead.

This is intended to give you some ideas, and there may be some valid criticism offered by an actual owner, or mechanic of your machine.

I actually do the above pre-start trick, (With silicone) to mine OUT if water, but never allow it to idle for more than about 5-10 seconds. Then, when I go launch, the carb has fuel ready. (I can't really recommend that to everybody!)

I hope this gives you some ideas.

What is happening is your carb, and fuel lines are empty of fuel, and your cranking for 5 mins just turns the carb pumps, and when it finally gets enough fuel, and pressure, she starts.

My suggestion above basically by passes your use of the starter to accomplish this, and uses priming it with a flammable substance, to fire it up, until she gets fuel. And, she will prime alot faster, with the motor running on priming agents (silicon in this case), than on the starter.

I am open to criticism, but the principle is sound.


N

 

[seadoosnipe]

Hit in the head with a nail.....

I'd say Nate hit the nail on the head pretty much.

The pumping of the throttle is like Nate said, to allow a bit of gas to be injected into the carbs from the accelerator pump. Not all Mikuni carbs on the Seadoo's have this. It is a nice feature when starting, to pump a bit of fuel.

Like he also said, if the fuel lines are empty, your peeing in the wind. But I think your problem with cold starting is a bit more than just no fuel in the lines.

You just got the boat. It's about time for the off season storage, which is the time of the year I do all my maintenance. You need to remove the RAVE valves and clean all the carbon deposits off. There is a thread in here for that procedure. You can use the search engine above.

Next, I'd remove your air box and flame arrestor to inspect your accelerator pump for proper operation. The accelerator pump is located on the PTO carb and has one, 1/4" line that comes from it, wraps down below the carb, "t's" off and one line over to the MAG carb. Looking into the throat of the carb, you'll see a little brass nipple, about 1/2" long at about 2 o'clock. With the boat in forward gear (throttle won't work unless boat is in gear {safety feature}), grab the syncro linkage on the bottom and give it a pull to wide open. You should see those nipples give a squirt of fuel. If you only see if from one or none at all, that little elbow that the rubber line connects to outside the carb is clogged. There is a small ball type check valve in there that gets gummed up. Get some brake or carb cleaner with that little red straw and give each one a squirt to clean them. When you squirt it, you should see it go through that nipple.

The other big problem with this system, is if the lines are left without clamps (electrical tie straps will work), sucking air. They need to be fairly tight so no air can replace the fuel.

Last, your low speed screws either need to be adjusted out a bit or you need to open the carbs and clean them up a bit. If you remove the carbs, be careful to pop off the syncro arm and disconnect the oil line on the opposite side of it's adjustment, that way, you'll be able to put it back together like it was.:cheers:

 

[ANDYstepan]

Wowza....This is the fastest response I've ever seen.

gents...thanks so much. I'll let you know how it turns out!
a

 

[swill777]

even after taking the carbs off and cleaning them, i find if I pump the throttle once before starting it helps a great deal... also, make sure your in water idle is at least 1500rpm, I bumped mine slightly higher to 1600 and it helps the engines stay running once they get started. I usually let them idle for a minute or two when the boat is initially started... after than, rock on.
and yeah, I adjusted the low-speed screws as well.. I believe I started at 1.5 turns out, and it seemed to work really well there so I left it.
and definitely look at those plugs for sure, at $2 a piece, it's a no-brainer to get new ones and gap em right.
you also might want to cut the plug wires, and re-terminate them if they are really old. mine were super corroded from the boat sitting.. took the better part of 7 minutes to do all 4.. totally worth it for an older craft.
boat runs freaking solid now... and starts MUCH better too.

 

[scooper77515]

Just went through the same thing, and nothing else to add to the previous guys except from my experience...

Get those carbs "rebuilt" and set the initial settings on the screws as listed in the book.

Mine starts in a second now, when I used to have to fight it and finally use starting fluid at times. Still a little "cold blooded" when cold, but if I hold the choke at half open for about 10-15 seconds, it warms right up.

And buy your plugs in bulk. On the two-stroke engines, I have found that just putting a new set in at the beginning of each weekend works out for me, rather than waiting for them to foul and the engines starting to sputter out on you. For me that is $4 on top of a full tank of gas...and less of a hassle than having them surprise me by fouling on the water, and having to do the swap when I should be having fun.

 

[Gunsrunner]

:agree:
I also start mine out of the water, i carry a squirty water bottle with dishwashing liquid and spay into the jet pumps before starting. Then once started let it run until its smooth running then shut them off and put it in the water. I find this puts less strain on the starters, because your not pumping water while trying to start.
I found it hard to start at first, but after repalcing fuel lines it starts much easier.
I think i had an air leak in the fuel lines somewhere, because the longer i left it the longer it took to start.
I image the lines were leaking back to the tank, so i had to prime the lines and carbies if it sat for to long.
Yes i think starter fluid will get it started faster as it will turn the fuel pumps faster, that will in turn prime the system faster.