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Opinions on changing choke to primer bulbs to assist in hard starting

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BMANN06

BMANN06

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I've been thinking of doing this changeover over the winter, as I am continually having starting issues with my two 787s.

I have gone through carbs pop off is just right, no leaks, fuel filters replaced etc etc..

Couple questions:

1. Will adding a primer bulb to my fuel system help? I've read it will but would like some confirmation.
2. Do you remove choke or does the primer system work with the primer?
3. Is there a kit anybody is aware of?
4. Has anybody done this mod and noticed an improvement?

Many thanks for input!
 
Have you tried different starting techniques? I used to have hard time starting mine. I have found that putting throttle 1/3 way up makes it easier to start.
 
I have put primer systems on PWC with no issues, but I think you will be pumping that thing along time to get the fuel to the lines. I know I have to pump the PWC alot if I havn't used it awhile to get the fuel in the primer system. I am not sure if that bulb could do it, might tucker the poor thing out. Most people put the primers on PCW's that have open flame arrestors or been known to have starting issues. Like I put it on my Yamaha GP1200 only because I rebuilt the carbs at the same time and it's know to have hard start. Usually stonger the pump and shorter lines help starting faster since you need the get the fuel to the carbs the fastest way.

You more than likey will need more hose to make it from the eninge bay to the dash. You usually just get enough for a PWC with not much left. You have to pull the carbs to install and drill out the plates, so I would just rebuild the carbs than. Rebuilding the carbs might just fix you issues. I just don't know if I would want that thin fuel line pulled that far from the engine bay. Always worry about fuel leaks.

Usually you mount the plungers in the same place as your choke cables and you usually need to drill the face plate to fit them it. I guess the easiest way to see if the primer system will help you is poor some fuel down the carbs and try to start them. That's all a primer system does is dump fuel in the carbs faster than the fuel pump can pull it to your carbs.
 
Personally I would leave the original choke configuration in place. It's really a very simple system and shouldn't be a problem. My 96GTI is a little hard starting from cold, on a ski SeaDoo expects you to be a contortionist. I pull the choke with my right hand and hit the throttle with my right forearm to get it to start, once warm it's fine. The other two ski's start with either no choke or very little choke. I'm not sure what the difference is. On all three I have to give a little throttle when starting.

You might want to check the choke cable and make sure it's adjusted properly.

Lou
 
Thanks for all the advice guys, I certainly would be a little leary of bringing fuel lines albeit they are small, all the way up the helm. Maybe I'll just pull these carbs off and go through them again. I was just hoping to have come across a fix one way or the other. One of them I can start with little to no throttle and tons of choke. The other is as lou put it ... contortionst!.
 
I'm testing a set up with some valves and an electric fuel pump. I prime by pushing pressure all the way around the fuel circuit. Then hit the valves a again to take the fuel pump out of the circuit. I did this because I added big spin on fuel filters, and getting it all primed was taking too much cranking after emptying the filters. No need to stress my starter anymore to prime the fuel filters.

My carbs also have accelerator pumps, and if all is primed, you can hear the fuel enter the carb when you hit full throttle if the engine bay is open (Engine off!)

What I do is Hit the throttle all the way in, then back it up to idle, and use the choke.

So far, since my last rebuild of everything, they start EASY.
 
Correct me if I'm wrong but, since our carbs are equipped with accelerator pumps wouldn't pumping the throttle a few times before trying to start the engine(s) net the same results as installing a prime bulb? Personally I'd want to figure out why it's hard to start before trying to re-engineer the fuel circuit. If you need tonnes of choke then it's lacking fuel, or too much air. Perhaps the carbs aren't synced? I know when I adjusted my throttle cable (incorrectly I might add) and the idle was too high I had a helluva time getting the boat started.

Just my $0.02...
 
:agree: I agree with what you are saying about the carbs,adjustment etc. because! the accel. pump on carbs has only enough capacity for ONE pump of the throttle.Once you hit it with a full stroke of the throttle it cannot be reprimed unless the engine is cranking.Unless you have an electric pump.Your ski ran for many years without the electric pump.That to me shows a problem that is yet to be found.Don't try to reinvent the wheel.Thats my $00.02
 
Yep pump the throttles a few times is exactly the same as using bulbs. I wouldnt be messin with whats there if you ever decided to sell it some people could look at that and think its a weird solution.
 
Cid6.7 said:
Yep pump the throttles a few times is exactly the same as using bulbs. I wouldnt be messin with whats there if you ever decided to sell it some people could look at that and think its a weird solution.
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I agree with you ... I have just been messin' with these carbs for so long I just wanted to hear if the soltuion (prime) worked for anybody else. I'll be taking the carbs off again tomorrow and go through them again. Hopefully I'll find the problem, and be good to go come next spring. It's just very strange. As once I finally get the one problem engine(carb) started it runs perfectly from low through mid range to wot without any hesitations, and it synched perfectly with starboard carb (with respect to RPM from idle through to WOT). Just starting it cold or restarting warm its such a process, it can honestly take me like 3-5 minutes to get this one engine started sometimes.
 
Check over all the carb setting, screws could be wrong, dual carbs themselves out of sync? Go over all the basics if both engines are doing it some has to be wrong with both of them.

Usually its something simple that's over looked
 
My boat only has 1 carb per engine....compared to all the hassle, buying new carbs was a great value for me, vs weekends of messing with them. I bet a motorcycle or small engine shop might also be able to rebuild them.

There's a lot of parts and passages in there....I'm not saying you can't pull it off...I'm saying I'm very mechanically inclined and have done almost everything else successfully to my boat, but carb rebuilding, I have not been successful at.
 
Hear yah ... my only problem is finding a reputable shop. I had replaced both engines a couple years back and had a shop rebuild them my carbs as a good measure (was told they were reputable) turns out I spent near $400 for them to clean them and set to run so lean I almost roasted out the top ends of my new engines. Hopfully it's something simple ... I'll scrap the idea of the primer system. Just wanted to hear some opinions.
 
If you want them done right with the right parts, send them to someone like Dr Honda, or better yet send them to the real Dr Honda. You got all winter.

Lou
 
BMANN06 said:
I agree with you ... I have just been messin' with these carbs for so long I just wanted to hear if the soltuion (prime) worked for anybody else. I'll be taking the carbs off again tomorrow and go through them again. Hopefully I'll find the problem, and be good to go come next spring. It's just very strange. As once I finally get the one problem engine(carb) started it runs perfectly from low through mid range to wot without any hesitations, and it synched perfectly with starboard carb (with respect to RPM from idle through to WOT). Just starting it cold or restarting warm its such a process, it can honestly take me like 3-5 minutes to get this one engine started sometimes.
Click to expand...

To me this sounds like bad spark plugs try swapping them out for new ones...
This happened to me this year couldnt figure out for the life of me why it was just suddenly so hard to start..
Changed plugs problem solved..Be sure their gapped properly as well..

Good Luck..!
 
good point Cid6.7, ive had hard start sometimes, as SOON as i put new plugs in, or clean the plugs, it fires right up..
Also, as far as contortionists are concerned(seen one last night in key west, strange people down there), ive already mentioned this to bigjake, and he said his ski doesnt have it, but im assuming, mine being a 96, that anyone with a newer boat or ski would have the same...
But with my choke, all i have to do is PULL THE LEVER OUT, then TURN IT SLIGHTLY to the right, and it STAYS IN PLACE til it starts, then you can release the choke lever..
I'll go take a pic of mine...im assuming newer boats and skis should have the same, so you dont hafta use the forearm..but whatever ski big jake has, he said his didnt have it..
 
as you can see, from pulling it out way too many times, ive had to jb weld and marine tex the housing back to the ski...but still works like a champ...
and big jake, if youre reading this, THIS was what i meant by pulling it out and twisting it..there is also a pic under the choke lever to tell u how to do thisch1.JPG
 
96spxpos said:
..there is also a pic under the choke lever to tell u how to do thisView attachment 10079
Click to expand...

That picture is the symbol I have always known for choke... it's a drawing of the choke plate closing on the air path...I don't think it's meant to be a picture of the lever being pulled and turned... although I can see why you would think that. It's on my weedwacker and chainsaw too, even though their levers look different.
 
Rebuilding the carbs are pretty much staight forward. You are just replacing gaskets and rubbers in carbs. It takes longer to clean them out. If you have external pumps even less parts to replace. Just get good quality kits and new needle and seat cost is about $60-$70 a carb. I think most places skip on the needle and seat because of the extra cost. Just set the needles to manual and should be fine.I usually set them to hign end of the turns out. Plugs are cheaper than engines.
 
ialonso said:
That picture is the symbol I have always known for choke... it's a drawing of the choke plate closing on the air path...I don't think it's meant to be a picture of the lever being pulled and turned... although I can see why you would think that. It's on my weedwacker and chainsaw too, even though their levers look different.
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lol, well either way, i've heard of some people starting their skis/boats by pressing the start button with one hand, pulling the choke with their other hand, and trying to give it some gas with like their forearm, toe, ear, tongue, or whatever other appendage they can use..lol. when all you gotta do is pull it out and twist it to the right.. hope this helps guys:cheers:
 
A tip for rebuilding carby's
Get a big piece of cardboard.Draw a double size image of what you see.Do this step by step.The shape,the holes the cavities.EVERYTHING.
Before you unscrew any jet that is adjustable or can be moved,Screw it IN and count the turns.Write this on the diagram of the carby you drew earlier.THEN take it out and push it into the cardboard where it/you have drawn it.Do this ONE screw at a time.
It may require you to draw 3 or 4 images of the carby as you see it.Each one a layer that you see when a housing etc gets taken apart.
The reason for drawing these and not photos is so it helps remember.If you take a jet out of the carb,write the jet size on your diagram.Magnifying glass helps.
To clean all parts.Use carb cleaner/soaker,what ever is needed.Compressed air is essential to clean out all passages.Blow some air in,find out where it exits.THEN reverse blow it.Always.Do this a few times with every passage
Blow out all or any jets.Reverse blow them.3 or 4 times.Hold up jets to a light so you can see if they are clear.You then need to suck air through them with your mouth.You will FEEL the air coming in through the jet on your tongue.
Never stop writing stuff on you drawings.It's you that has to put it back together.
I hope this helps anyone that is trying a carb rebuild.
I worked for Mazda Aust. and this was SOP for every 4 barrel carby that was on a rotary motor.They were a complex carby and just before E.F.I.We had boards made up with all the diagrams printed on them and holes predrilled to place all the parts in them.We worked on them all the time and still had trouble with tiny small bits.

Put this on a sticky if you think it will help the site
 
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96spxpos said:
as you can see, from pulling it out way too many times, ive had to jb weld and marine tex the housing back to the ski...but still works like a champ...
and big jake, if youre reading this, THIS was what i meant by pulling it out and twisting it..there is also a pic under the choke lever to tell u how to do thisView attachment 10079
Click to expand...

Wow ... you have no idea how many laughs I've had from passensgers looking at me bending and twisting to hold choke and applying throttle and hitting start button!! I guess it's better late than never!! I just tried it and sure enough if you twist the lever it locks!! Many thanks!!

I have solved this problem turns out carbs are fine and it was my lack of black caps (they were literally melted to nothing) on the rave valves that was causing the hard starting.
 
I read your other thread about the melted rave caps.Hope all goes well.Why were the melted???That isn't normal
 
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