CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

[FreeBeeTony]

Now I don't know what to do! <br /><br />I changed the timing in either direction and it didn't affect the problem......

 

[ziggy]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

bummer man, ya got a couple of post going on yer project here. can ya give us a consise list of what's been R&Red and what's been checked out and deemed ok so we all can start thinking again. i can't remember what all ya have done to it.

 

[newport dave]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

FreeBee,<br />I mentioned this before, but I think I would recheck the exhaust system for restrictions. Pull the risers and pull the drive check the Y pipe all the way down and look in the exhaust passages in the outdrive.<br /><br />Also, check the outdrive gear ratio.<br /><br />Dave

 

[FreeBeeTony]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

This is what I have done so far:<br /><br />1) Rebuilt/replaced carb<br />2) Bypassed entire fuel system from input of fuel pump to tank by connecting separate tank to input of fule pump<br />3) Checked fuel pump pressure, ~6# @ 1800 RPM<br />4) replaced: cap, plugs rotor and wires<br />5) Checked and reset timing<br />6) Swapped out ignition module<br />7) Checked voltage: ~14v when running<br />8) oil pressure ~50# when running at ~2500RPM<br />9) Temp ~150* (fully closed system)<br />10) Compression 140-170<br />11) Removed elbows after risers to inspect flappers.....they were fine<br />12) Risers are cool to the touch<br />13) Checked for proper prop, found 15" pitch<br /><br />Don't know if I missed anything.<br />If I had an exhaust restriction, would the risers be cool to the touch?

 

[newport dave]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

An exhaust restriction would not effect the riser temps at all. It will produce the exact symptoms are are having.<br /><br />Dave

 

[Haut Medoc]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

I think Dave has some excellent suggestions.....You have thrown everything but the kitchen sink at it. If the new carb didn't work, your issue is probably not fuel related. If I remember correctly the problem was bogging @ 3200 rpm. If the gear ratio was wrong I would think that it would just wind out,(not bog). However, I still would not rule it out. I would look for the possible exaust restriction first....J

 

[ntheyer]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

By the way FreeBee, I have the exact same problem it seems. Mine is on a Merc 181 4 cyl with Rochester 2bbl carb though. I did everything and more than in your list and still have the same issue. I am at a complete loss for what the problem is. I made another thread for help, but don't know what the problem is. Maybe we'll find someone who knows? Sorry I can't help.

 

[ntheyer]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

Free Bee, can you email me your phone number or call me at 815-307-4164? my email is ntheyer@gmail.com. I would like to talk to you a bit about this issue. Mine does the exact same thing. 3200 rpm bogging out.<br /><br />Nicholas

 

[Don S]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

Here's another long shot, check the oil. If it's over full drain it out to the full mark and try it.

 

[FreeBeeTony]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

How can I check the exhaust for restrictions without taking the boat out of the water?<br /><br />If anything the oil was on the low side........that's the topic of another thread I haven't started yet. Wanted to put this aside first!

 

[Haut Medoc]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

You can't........The drive needs to come off so you can look into the exaust bellows..... I saw a post not long ago where an exaust flapper was stuck there and it sounded like your symptoms...J

 

[Don S]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

How can I check the exhaust for restrictions without taking the boat out of the water?<br />

You can't, but you REALLY need to check it.<br />Just because the shutters in there now look good, doesn't mean the old ones were ever removed if they were replaced. Did the previous owner mention any overheats?

 

[FreeBeeTony]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

He never said anything about overheating.........<br />Is there any reason to pull the risers? Any chance there is something wrong there? Or would the risers be hot if there was a problem there?<br /><br />Another note..........seemd like it will run all day at ~3200, then when I try to easy up a little more the problem occurs. Then it order to "clear" the problem it seems like I have to back-off to lower than ~2800 and then I can get back to 3200. I don't know if I am making sense here.<br /><br />Guess I am going to have to pull it out of the water somehow. I don't have a trailer for this boat yet.

 

[Don S]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

No reason to pull the risers, you already looked at the shutters, and you aren't overheating.<br />it's probably just going to be pull the drive and look into the exhaust bellows for an old shutter.<br />When you borrow the trailer or find a lift somewhere, have all the new gaskets, and seals handy to replace the drive and change the gear lube while your at it.

 

[FreeBeeTony]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

Don........how confident are you about this?

 

[Don S]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

Let's put it this way. You bought the boat with the problem, by now the bottom probably needs cleaned anyway and the outdrive needs serviced since you have never seen it out of the water.<br />Since you are on Long Island, I assume you are boating in salt water, if so the bottom may be so dirty with barnicals and slime that your engine can't pull more than 3200 rpm. So, to check for broken shutters, you have the ability to check a lot of other things too.<br />1. Alignment (You don't want to pull the engine to replace the coupler do you????)<br />2. Impeller (Replace if you don't know how old it is)<br />3. Change gear lube. (It has to be overdue)<br />4. Clean Bottom (You would be surprised how little it takes to kill rpms)<br />5. Check for shutters in exhaust<br />6. Check ujoint bellow (before it goes bad and costs you a fortune to fix.)<br />7. Check and lube gimbal bearing.<br />8. Replace Anodes (Unless you want the drive to corrode)<br /><br />Even in fresh water, you need to check these things.

 

[FreeBeeTony]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

When I first looked at the bpat it was not in the water, The bottom and outdrive were painted and new anodes were put on prior to being put in the water. The bottom can't be that dirty, it'n only been in the water about 2 months. The outdrive was supposedly serviced before installation. Wish I knew to check for the exhaust passage when I first looked at it.

 

[ntheyer]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

This may be a clarification for all.... FreeBeeTony, I just pulled my riser and found that I have no flapper at all. The flapper is missing... The symptoms you are describing are EXACTLY the same as mine... Don S.. if there is no flapper, or if it is broken, is this the symptom you will get. Or is this only if the flapper is stuck shut? My exhaust is completely free and clear; no obstructions.. This may answer questions for both of us FreeBeeTony.

 

[newport dave]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

Are you kidding me? The boat has been in the water for two months and the bottom has not been cleaned?<br /><br />Clean the bottom and try it again.<br /><br />Dave

 

[Don S]

Re: CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING

Pardon me for asking Tony, but you do know how and why to use the outdrive trim don't you.<br />Hate to find out all this time you have been running with it full down.