1985 200hp Mercury

Crranks and idles fine. When you put it in gear it wants to bog out. If I let it run this way(like its about to bog out for awile and bump the choke) and slowly keep ingaugeing the throttle, it will finally catch and I can go wide open. After this point and further up the river, if I slow all the way back down to neutral. I can push the throttle wide open and it WILL NOT bog down, IT TAKES RIGHT OFF. It only happens when I first start the engine or after Its been cut off for a few minutes. I have replaced fuel lines, screen,fuel pump, and rebuilt the carbs. Whats the problem?? Need help!!

Re: 1985 200hp Mercury

jbcc2500 said:

Crranks and idles fine. When you put it in gear it wants to bog out. If I let it run this way(like its about to bog out for awile and bump the choke) and slowly keep ingaugeing the throttle, it will finally catch and I can go wide open. After this point and further up the river, if I slow all the way back down to neutral. I can push the throttle wide open and it WILL NOT bog down, IT TAKES RIGHT OFF. It only happens when I first start the engine or after Its been cut off for a few minutes. I have replaced fuel lines, screen,fuel pump, and rebuilt the carbs. Whats the problem?? Need help!!

Click to expand...

did you replace the bulb (Sqeezer) if the check valve is bad it could do this. Just wondering ?I,m assuming when you did the carbs you checked the float level as not to overload the carb. 1 more thing have you adjusted the air mixture screw after rebuild?

Re: 1985 200hp Mercury

I'd guess you're running a bit lean at idle. Could be some of the fine drill holes under the idle circuit covers are plugged. Also the linkage might be a bit out of adjustment. That engine likes a little timing advance before the throttle valves start to open. If folks have been "tinkering" on this engine, a formal linkage and timing procedure on it might just fix it up.

If pumping the bulb seems to help restart, you might be looking at a combination of a bad bulb and a small leak in the fuel line.

If you have WH carbs on it (likely) you don't have any idle adjust screws.

If you go into the carbs, float height is critical. Also if it has the old foam floats in it, you'll have to find a set of later carbs to put plastic floats in. I doubt it, though. Normally the foam floats just flood out.

hope it helps
John

Re: 1985 200hp Mercury

Maxz695 said:

did you replace the bulb (Sqeezer) if the check valve is bad it could do this. Just wondering ?I,m assuming when you did the carbs you checked the float level as not to overload the carb. 1 more thing have you adjusted the air mixture screw after rebuild?

Click to expand...

I have replaced the bulb, What is this check valve your speaking of. I have run this boat three times and problem is gradually getting worse. I have not adjusted air mixture screw (not sure where its at) When I say I rebuilt them, All I did was take them apart and clean thoroughly and use a lot of compressed air and let them soak. I then put them all back together. Did not remove any of the seat screws just took off drain plugs and cleaned floats and ext.

Re: 1985 200hp Mercury

It does have the foam floats. Where are the idle circuit covers at. I put a new fuel hose on it. Once the bulb is tight, should it stay tight as you are running the engine or just firm or what?

Re: 1985 200hp Mercury

jbcc2500 said:

It does have the foam floats. Where are the idle circuit covers at. I put a new fuel hose on it. Once the bulb is tight, should it stay tight as you are running the engine or just firm or what?

Click to expand...

I'm assuming dual float WH carbs. Look around for WH anything, even off a 135 from 88 later and they'll have the plastic floats in em.

The plate on top of the carb covers the idle circuits.

The bulb will get soft when running. You're sucking fuel through it. It should not go flat, though.

If you went through the carbs without replacing the gaskets, you put trouble in. Do it again and replace all the gaskets, including the washers under the seats. While you're at it, look up the jet sizing and make sure that the right jets are in the right places. If you get me numbers off the carbs, (that plate again) I can tell you what should be where. Cylinders 2 and 5 could be a bit different (richer) than the others by design.

hope it helps
John

Re: 1985 200hp Mercury

Just had a thought. On gradually increasing fuel troubles, the fact that older black internal fuel lines tend to shed their inner tube in little pieces comes to mind. Fuddles it up pretty well.

Re: 1985 200hp Mercury

ok, I will get these numbers and post tomorrow, thanks j_martin. You have helped me more than once