Help running rough

Paul F · 24 January 2010, 09:33

Have Honda BF50,3 carb model runs rough near the 3k mark,will run ok at fast idle but not under load, gets to around 3k runs ilke crap and then will cut out,restarts ok.
Took carbs off and cleaned them no joy.
If i disconnect bottom carb and open it up on its own the fault still there. I thought this was prob. However if i still leave bottom carb off of link arm and open up on top and middle carb, the prob STILL happens. Has now got me puzzled. Did have water in fuel,but got rid of that problem.

Any ideas anyone,please

outboardtech · 24 January 2010, 10:34

Hi there , it sound's too me that you need to get yourself a set of VACCUMMATE CARBURETTOR TUNER TOOL . This device will allow you or the Tech to Syncronize , balance , and tune the Carbs and the Manifold's correctly . This procedure is very important when coming too setup , tune and adjust carbs . Especially when you have had them off to clean . It's not just a matter of taking them off and putting them back on like a two stroke outboard , there is alot more involved . The Carb sync screw's can only be adjusted with this tool . I have tried several time's to ear adjust and it really end's up being a nightmare . This would be the first stage I would go and also while doing this procedure have a fuel pressure gauge connected too the outboard and a Tach to clarify you engine rpm and fuel pressure . It may be worth getting someone to do it for you ( dealer ) .

Paul F · 24 January 2010, 16:39

None of the screws have been touched as paint still on them and prob occured before i cleaned them
Paul

outboardtech · 24 January 2010, 16:58

Paul is the CHOKE switching off . This is connected too the bottom Carb and if the linkage is stuck ON then the choke will be ON . I have had many of these issues were this has also happened .

Paul F · 25 January 2010, 08:15

will check,but it got an electric thing sitting on the top carb.
Paul

9D280 · 25 January 2010, 10:26

If it runs OK at idle, do you have a throttle sensor on one of the carbs?

I had one of them fail on a Suzi - would idle all day and not so much as cough- open the thirottle by more than a few defgrees & it had a canary fit.

When you open up, is there a repeatable time lag before it dies? (Usually the engine management thinking "oh oh.... no throttle movement detected but the revs going up.- that's not right....wait for a bit see if it cures itself....nope, something's wrong - switch off.")

Sonar · 25 January 2010, 10:54

Quote:

Originally Posted by Paul F

Have Honda BF50,3 carb model runs rough near the 3k mark,will run ok at fast idle but not under load, gets to around 3k runs ilke crap and then will cut out,restarts ok.
Took carbs off and cleaned them no joy.
If i disconnect bottom carb and open it up on its own the fault still there. I thought this was prob. However if i still leave bottom carb off of link arm and open up on top and middle carb, the prob STILL happens. Has now got me puzzled. Did have water in fuel,but got rid of that problem.

Any ideas anyone,please

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http://www.marineengine.com/cgi-bin/discus/discus.cgi