1984 Bravo Carb Questions

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hms11

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Hello Everyone!

I have a 1984 Bravo that refuses to idle. I believe I am missing pieces of the starter jet assembly. When I unscrew the choke and pull the choke assembly out of the carb, I don't see anything below it, where I think the start jet is supposed to be. Does anyone have one of these that they would mind popping apart and taking a picture, or does anyone have any insight? The weird part is I don't see any threads down in there really, so I'm worried something is broken off as well.

The sled runs like garbage below 1/2 throttle or so with the choke off and is almost impossible to keep running. With the choke on, it won't idle but runs absolutely mint everywhere else. As soon as you come up just off idle, or a really high idle (right at the edge of clutch engagement) it will run great.

My brothers and I all grew up on this sled, and then it went off to a buddy of my dads for his kids to grow up on. At some point in those years some pieces got lost or broken. Now that my boys are getting close to the age where they can start to enjoy being towed around the yard on GT's, I'd love to get this thing running properly again. As it is, I can use it no problem, but without being able to idle the wife isn't quite as excited to deal with it.
 
That's whats making me scratch my head. I can't tell if I have parts 4 and 5 or not. When I pull the choke assembly out on its cable, I don't see any jet to remove, and I also don't see any threads, so needless to say, I'm a bit confused. It doesn't look like anything is missing, but it also doesn't look like there is a jet in there.

That's kind of why I was hoping to get an actual picture of inside the choke/start circuit of one of these carbs. The schematics are great, but trying to translate that into an actual part can sometimes be confusing, especially if you aren't really sure what you are missing, or if you are missing anything.

I've done a full clean of the carb (twice), cleaned all the jets and set the float level, so I'm pretty confident it's either that I'm missing the start circuit jet completely, or I have an air leak somewhere in a crank seal or something.
 
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There is no jet under the choke plunger. It is just a tube down into the bowl. When you unscrew the choke from the carb, there should be a spring and plunger on the end of the cable. Maybe share a pic? Or PM me
 
jjmoneysauce said:
There is no jet under the choke plunger. It is just a tube down into the bowl. When you unscrew the choke from the carb, there should be a spring and plunger on the end of the cable. Maybe share a pic? Or PM me
Click to expand...
I have a bravo that was doing something very similar to that after a lot of pulling my hair out all it was that the float needed to be adjusted ran perfect after that
 
jjmoneysauce said:
There is no jet under the choke plunger. It is just a tube down into the bowl. When you unscrew the choke from the carb, there should be a spring and plunger on the end of the cable. Maybe share a pic? Or PM me
Click to expand...

I think I may have figured out my confusion then. When looking at the diagram, I assumed parts # 4 & 5 threaded into the carb body, but it sounds like you are saying they are actually the brass parts on the choke cable, correct? If so, I think I have everything I need.

I'll try and take a picture in the next day or so when I have a chance to get out there and work on it again.

If everything is there, it sounds like I might be into a crank seal, or some other engine side air-leak because this thing runs perfect if the choke is on, just off idle but won't idle, and won't stay running under 1/2 - 3/4 throttle or so with the choke off.
 
ttr said:
I have a bravo that was doing something very similar to that after a lot of pulling my hair out all it was that the float needed to be adjusted ran perfect after that
Click to expand...

I'll double check the float adjustment but it seemed correct when I had it apart.
 
It is definitely acting too lean. I'm going to pull it apart again and clean it for the 4th time, I also have a line on another carb just in case. When I get it apart, I'm going to snap a picture of the choke cable end and down the choke tube so we can see if I am missing something.
 
It appears to be flowing freely, no airbubbles that I can see.

I've got an in-tank filter on order, I'm gonna throw one at it regardless, can't hurt.
 
Get all those little holes. If choke keeps it running, there's fuel in the bowl. I think you said the level was ok. Get the pilot jet out and cleaned and clean the pilot circuit. I like to shoot cleaner in the air mix screw hole and then blow air in that hole. Don't give up yet!
 
That diagram is very helpful. It definitely helps put things in perspective when looking at the issue. Considering almost the entire issue is at 1/4 throttle and below to idle, I definitely think this is in the pilot circuit. I might have a chance to pop the carb off this sled again tonight. I'll do a complete clean again, paying special attention to the pilot screw area.

Thanks for all the help guys!
 
Well, other than being an idiot, and forgetting to take ANY pictures of anything, I've made some progress, but still fighting the idle.

I did another full tear down on the carb last night, paying particular attention to the pilot jet and circuit. There was definitely still some crap in there. I re-assembled the carb, set pilot jet to 1 1/4 turns out and put it all back together.

The sled now runs PERFECT without the choke once it's warm and the choke has a measurable difference in the running of the sled when warm, it doesn't like the choke, just as it should be. Good throttle response, doesn't cut out at WOT and runs around at 1/4 throttle and below no issue at all, no stumbles, no problems.

It still won't idle. If you hold the throttle just to the point that the clutch almost wants to engage and start pulling the sled forward, it runs perfect. The second you drop that slight pressure on the throttle it shuts off like you hit the kill switch.

Now, something I've noticed that seems to be a bit different about this carb compared to all the rebuild/parts diagrams, it doesn't have the electrical "switch" for the throttle stop that all the diagrams show. It's hard to tell if it is a lean or a rich die, because it happens right as soon as you let the throttle go and it is an immediate shutoff. I'm leaning towards too lean just because that's been the running theme of problems here.

On the plus side, it runs well enough now to drag my boys around the yard this weekend on their GT's!

Anyways, I should have the fuel filter here this weekend and I think I might rebuild the fuel pump just because parts are cheap and maybe it just isn't pushing enough fuel at an idle? Seems unlikely, but who knows at this point.
 
Have you set the idle speed to spec? It could also still be just slightly lean, so that it idles when you're warming it up but then when you apply throttle it starves it a bit and thus when you let off it dies. Adjusting the "pilot jet" out a bit more may help, such as going to 1-1/2 turns out.

Those pilot jets can be a pain. I always hold them up to a light, you have to wiggle them around a bit to see all the way through it, and make sure you can see a nice ROUND hole through it. I've had many times that cleaner or air wouldn't clear them and so I cut a wire off of a wire brush and run it through it, blast with cleaner and air again, check it up to a light again.
 
mod-it said:
Have you set the idle speed to spec? It could also still be just slightly lean, so that it idles when you're warming it up but then when you apply throttle it starves it a bit and thus when you let off it dies. Adjusting the "pilot jet" out a bit more may help, such as going to 1-1/2 turns out..
Click to expand...
Make it a strong 1-1/2. But yes .... out towards 1.5 is probably the way to go.
 
mod-it said:
Those pilot jets can be a pain. I always hold them up to a light, you have to wiggle them around a bit to see all the way through it, and make sure you can see a nice ROUND hole through it. I've had many times that cleaner or air wouldn't clear them and so I cut a wire off of a wire brush and run it through it, blast with cleaner and air again, check it up to a light again.
Click to expand...
My pilot cleaner is the wire within a bread wrapper twist tie.
 
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