1997 hond bf50a wont go over 4000 rpm

[wayneis2]

I am new to the site this is my first post. I am having some trouble with my 97 honda bf50a it will not go over 4000 rpm under load. It idles fine in gear and will run like a champ until 3500-4000 rpm. If you give it throttle quickly it will die but advance it by 500rpm at a time it will go good till 4000. It happend over the 4th comming back from fireworks all of the sudden it lost power thought it was trash sucked up from sloshing with the wake. Oil temp and water temp light never came on. So far this is what i have done.

Cleaned gas tank, changed water seperator filter, changed fuel filter, new bubble, rebuilt carbs, sync carbs, changed plugs
changed fuel connector ends, new oil and filter, checked timing and spark is good.

Also if i squeeze the bubble it does nothing but i can work the manual choke a little bit and it will pickup 400-500 rpm but i cant leave it out or it will die. At wot it does sputter and bog. If someone could give me some insight on what could be going wrong so im not throwing parts at this thing any help would be greatly appriciated. Thanks in advance.

 

[mke039]

Re: 1997 hond bf50a wont go over 4000 rpm

Check compressions....sounds like you have done everything else

 

[Sea Rider]

Re: 1997 hond bf50a wont go over 4000 rpm

A 15 year oldie, probably worn, dried, cracked fuel pump diaphragams or head gasket already dried, hardened, out of torque not sealing combustion chamber properly, one of the symptoms are sputters and bog down at wot when everything is ok at idle speed without engine load.

Happy Boating

 

[Harritwo]

Re: 1997 hond bf50a wont go over 4000 rpm

I just finished working on a Nissan with help from Paul that had similar issues. What i finally found was the fuel system was sucking air. The fuel filter housing was cracked, the fuel inlet to the carbs (That little plastic ell) was cracked, there is two plastic filltings on the plate behind the carbs that were cracked and sucking air. While these parts are NLA, there are fixes for them. I made my own fuel fittings for the carbs, placed RTV over the cracks on the vacuum lines, and replaced the filter housing, all fuel lines from the tank to the carbs, and she will wind out like no ones business.

My engine was a N55C i believe, 55 HP Nissan 88 year, and Paul had a service manual and if the parts are available he was able to obtain them. He also has a wealth of knowledge as does the Tohatsu Guru.

I hope this helps.

George

 

[Sea Rider]

Re: 1997 hond bf50a wont go over 4000 rpm

Honda has nothing to do with Nissan and boater has already > Cleaned gas tank, changed water seperator filter, changed fuel filter, new bubble, rebuilt carbs, sync carbs, changed plugs changed fuel connector ends, new oil and filter, checked timing and spark is good.

Happy Boating

 

[Harritwo]

Re: 1997 hond bf50a wont go over 4000 rpm

I realize that Honda and Nissan are seperate engines, My point was I was sucking air where you would not imagine it would. Symptons were the same, run good on muffs, run good until 3500 rpm, then would sound like it was struggling, It was multiple air leaks between teh fuel filter and the carbs. OP might just verify that the system has no air leaks and see if that helps.

 

[Sea Rider]

Re: 1997 hond bf50a wont go over 4000 rpm

Got the point, have had just 1 issue related to engine sucking air, but engine droped dead clean at near wot, in some cases when experimented uneven engine rpm, sputters and bogs down at wot, the cause was entirely related to oldie head gasket failure. Anyway check fuel & combustion related.

Happy Boating