BF-30 Stalling

[swebster@rogers.com]

Hi All<br /><br />Hopefully someone here can help me with my problem. Have a BF-30 that is probably 5 years old. It used to run great but lately it stalls constantly - I can get it to idle, but when I add throttle, there appears to be what I can only describe as a "dead spot" where it "feels" like it is suffering from a fuel starvation issue (or perhaps too much fuel - not sure). The idle does feel a bit rough however.<br /><br />I have adjusted idle settings (brought it up a little), cleaned and re-gapped plugs, changed the fuel filter, and even messed a bit with the mixture settings on the carbs, and still have the problem. I do not have the gear to dive deeper with calibrating the carbs, but any other tips anyone can offer would be helpful.<br /><br />If you coax the throttle to get past the "dead spot" it will throttle up and run fine at higher RPMs, but most of the time it will die in the "dead spot".<br /><br />I'll take a stab at opening the carbs and checking them out if some one can tell me how to do that, just to see if something is found it's way in there and it causing the problem.<br /><br />Steve<br />swebster@rogers.com

 

[hondon]

Re: BF-30 Stalling

You have a dashpot/accelerator pump on this unit.Is it still distributing air pressure to those carbs when you squeeze this thing?

 

[swebster@rogers.com]

Re: BF-30 Stalling

Thanks for the reply. <br /><br />Sorry you lost me - are you referring to the small grey square pump at the bottom left rear (looking from the tiller side)? Not sure - how can I tell if it's distributing air?<br /><br />This one is really weird. If I very slowly and gently push the throttle forward, it will get through the "dead spot" and come up to RPM and once it is past the dead spot it seems to run ok, but if I push the throttle forward in a normal fashion, it is sure to stall.

 

[hondon]

Re: BF-30 Stalling

You are looking at your fuel pump , but you are looking in the right general area.Have someone operate the tiller while you watch what happens back there.You will see that as you open the throtle you are activating linkage to a mushroom shaped dashpot with a hose and check valve running off of it.This is your accelerator pump.If that dashpot or check valve have failed or the linkage has come out of adjustment or undone,there you have it.There are other possibilities as well but this is a good place to start.

 

[swebster@rogers.com]

Re: BF-30 Stalling

Ok,<br /><br />I think I know what you are talking about now. I was looking at that the last time I was troubleshooting, and that assembly did appear to make a big difference when I manually actuated it - I did not get the sense it was working properly - the linkage is there, but I did not see it move or activate when I add throttle - that is, the linkage seems to move but I did not get the sense it moved enough to make any noticable change in behavior as throttle was added, except when I manually moved the linkage. The check valve itself, is it the brass mushroom shaped component (looks to me like a vacuum activated valve) or is it the small grey cyclindrical component in the fuel line after the brass valve? <br /><br />The copper coloured screws in the corner of each carb (the ones opposite to the drain screws) - I assume these adjust the mixture or jets on each carb correct? Do I need any special tool to properly set those, or can they be done by ear? My brother built a tool he used to adjust the sync on the carbs on his motor bike and suggested I may need to use it when adjusting those screws - although I thought that sort of sync adjustment was accomplished with the spring-tensioned set screws (the ones with the yellow paint on them which I've not touched) on each carb.<br /><br />Thanks again for you help.<br /><br />sw

 

[hondon]

Re: BF-30 Stalling

Syncing multi carb engines usually involves some sort of special equipment,and this engine is no exception.Idle mixture screws are at the top rear of the carbs.It really sounds like you are screwdriver happy ,with little guidance other than me.BE CAREFULL.You can really throw this engine dangerously out of wack without some reference material to work from.

 

[swebster@rogers.com]

Re: BF-30 Stalling

I did some further testing this weekend - took out the check valve - was able to blow air through one way and not the other, so I presume that it is ok if it is supposed to be a one-way valve. The dashpot on the other hand I am unsure about. The linkage is obviously there and it moves when you move the thorttle. If I manually push the linkage up it does have a minor effect on the engines behavior, but not much.<br /><br />I've not done anything with the carbs - I was just questioning what was involved in setting them up as far as special tools went.

 

[swebster@rogers.com]

Re: BF-30 Stalling

Just a postscript on this. Yesterday I took the entire intake manifold off and dismantled all three carbs and cleaned them. The reason I decided to do this is I verified that I was only running on the number 2 cyclinder. The jets on both the #1 and #3 carbs were clogged up. Took the carbs apart, cleaned them, reassembled and re-installed. It is running like a NEW engine again!

 

[silviomifsud]

Re: BF-30 Stalling

Hi swebster<br />i have a bf50 and seem to have the same problem. do you have a user manual you used to do this job? i'm not very keen on removing the carbs without having something to follow.

 

[swebster@rogers.com]

Re: BF-30 Stalling

I bought the shop manual from Honda - would recommend you do that before you drag the intake manifold off (which you will have to do since its hard or impossible to properly service the carbs without doing so). You will need a gasket for the intake manifold as well, and likely another for the carbs where the attach to the manifold. Manual for the BF-30 was around $65.<br /><br />This problem by the way, is likely caused by putting the motor away without allowing all the fuel to burn off from the carbs. A routine of disconnecting the fuel line from the engine and allow the motor to run for the 2-3 mins on the remain fuel in the system will likely eliminate this problem as the chances of the carbs becoming gummed up from the residual fuel is greatly reduced. Something I never did but will from now on.<br /><br />Steve

 

[silviomifsud]

Re: BF-30 Stalling

Hi Steve<br />thanks for the info. yesterday i managed to find a munual for sale at www.helminc.com. the price was about $67. But they asked for an additional $159.5 for postage and handling - which is far too expensive. so i'm tryingot contact some relatives i have in canada to see whether they can send it to me.<br />Steve, i'm not 100% sure that emptying the Carb would solve the problem. i'm sure they empty the carb on 2 stroke engines but that is understandable since they have 2 stroke oil with the fule in the carb. Whatever, it's still worth a shot. My other problem now is getting the parts from the local supplier! they're useless over here and almost everything is on order.<br />may i ask the type an size of your boat cos i'm after changing my propeller. My boat is a Fletcher 14.4 ft and the motor woul deasily overrev even when loaded with 3 people. i still have the standard prop - 11.5 with a 13 pitch, i believe. once i'll find the right one i'd try to go for a stainless steel one, but i'm still looking for the optimal pitch.<br />Thanks once again and regards<br />Silvio

 

[swebster@rogers.com]

Re: BF-30 Stalling

Hi Silvio ,<br /><br /> That is a ridiculous amount to charge for shipping, unless of course, if you live on the Moon. I also tried the same company when I was searching for my manual and I almost bought it there, however when I was about to check out there was some fine print that stated the manual was a copy of the original Honda manual and some diagrams would be missing as they could not be scanned! When I read that-I decided NOT to buy from Helm Inc and I called the Canadian office of Honda. They had stock on the manuals So I got it from there via a dealer of course as they would not sell directly to me. That too was a pain as the first dealer they sent me to dropped the ball - I ended up talking to 3 different Honda dealers before I Could find one that wanted to take my money! The whole experience left me feeling that Honda Canada was not serious about their marine operation in Canada. That said, they do have the manuals in their Canadian warehouse and the dealer that was finally able to help me was Pieces Marine in Oakville, Ontario.<br /><br /> My BF-30 is hanging off the back of a 14' Zodiac.I have not thought much about the prop-maybe I'll do that next year. Re-propping can be something of a Black Magic art. There are obviously guidelines around pitch and size relative to the load you can present to the Shaft, but there is a range within which you can work, and my experience has been to find a prop shop willing to loan you a few props in that range and go try them. You do not want to over speed the motor, or conversley, overload it either. Honda I believe has a recommended range for each motor.<br /><br />Hope that helps.<br /><br /> Steve

 

[Alaskantech]

Re: BF-30 Stalling

Steve,<br /><br />You might want to check your carb synch after the cleaning job. You need to have a vaccum gauge set up or similar type device to make sure the carbs are working together. Any Honda dealer should be able to set you up fairly easy. I always check the synch after I've run through the carbs.