stall when go into forward

**Dave Neptune** · 06-28-2011, 09:24 AM

Stalling

Ken, sounds like a fuel issue. The idle is fine and when you go in gear the demand for fuel rises and the carb can't deliver enough it dies. Try fiddling with the choke by engaging it to see if it makes a "bit" of differance. If it does you probably have a plugged main jet or a blockage slowing delivery upstream from the carb like a filter.
Also check to be sure the fuel line connections are tight and not leaking air into the lines.
What you are describing is a classic fuel starvation senario.

Dave Neptune

**KenVoodoo** · 06-28-2011, 10:24 AM

Hello,
I did try the choke in various stages of engagement, and it didn't seem to matter. Does the fuel starvation idea make sense if after getting lucky and being able to go forward for a 5 minutes it then worked without a problem?

I added a small filter between the fuel pump and carb (one of the little plastic ones..maybe not the best idea?) maybe I should replace that.
thanks
Ken

**sastanley** · 06-28-2011, 10:47 AM

Ken..electric pump or mechanical? You can bypass the oil pressure safety switch and make the electric pump run, or, if mechanical pump there is a bale on the pump you can operate to pump fuel. You can remove the hose to the carb (or the carb bowl plug itself) and see if fuel comes out appropriately..don't forget a catch can of some sort...mason jar, etc.

FYI - The plastic filter is not USCG compliant for inboard installations. Certainly OK for troubleshooting, but I would not make it a permanent installation. What are you seeing in the filter?

If you are tied in a slip, you can do lots of under load troubleshooting right at the pier.

**Marian Claire** · 06-28-2011, 11:00 AM

You mentioned tightening the stuffing box. Maybe try adjusting it back as it was and test. Just to eliminate a binding problem. Dan S/V Marian Claire

**KenVoodoo** · 06-28-2011, 11:12 AM

Plastic filter is mostly getting darker....so obviously doing some good. It is a mechanical fuel pump. It does look like there is a fair amount of air in the filter, which I was surprised at, would probably help the filter efficiency (area exposed) if I purged that. Will probably go buy a new filter, purge it and see if that helps.

I am at a mooring, will try loosening the stuffing box, although the rate it was leaking before I adjusted it was worrisome.

thanks
ken

**sastanley** · 06-28-2011, 11:49 AM

Ken, if you are seeing a few drips per minute at the mooring that is fine. Dan's comment is valid, however, you should be able to spin the prop shaft by hand with the engine off..that will tell you if the stuffing box is binding. A better fix for the stuffing box is new packing, but we'll get to that when the time comes.

You may want to consider a Racor spin-on style filter also. How old is fuel? Ethanol based fuels don't last long and boats are especially vulnerable to the negative effects of ethanol fuel. I don't like the 'dark stuff' in the filter.

I am going to stick with Dave's advice related to fuel starvation. Dark fuel means all kinds of crud could be getting stuck in the carb somewhere. Sometimes you can flush it out by squiring a few ounces of fuel into a jar/can from the drain plug in the bottom of the carb bowl. If it is not clean, we have more things to deal with that will likely solve the running issue as well. Clean fuel eliminates contaminants getting in the carb.

Here is a pic of the carb showing the two possible carb drain locations, in case you are not familiar with them. The main passage plug has a fiber washer so treat it with care! Ignore the choke stuff, I re-used a picture from another discussion about the choke.

Attached Files

**KenVoodoo** · 06-28-2011, 12:02 PM

I will try spinning by hand this evening when i get to the boat. Repacking is an option when I get the boat out of the water at the end of the season, but I don't think it is viable while in the water....I was thinking about doing this before launching, but at the time felt that I might do more harm than good.

I have an old style filter/water seperator in front of the fuel pump (Perko , it could use a new element though, next order from supplier). I drained the tank and refilled it about 2 weeks ago, so the gas is new.

I know about the main passage plug, didn't know about the other one. I had the carb off last week and cleaned it out...this went along way towards helping the engine idle nicely (as did opening up the idle mixture screw a turn).

So I think in order I will:
1) turn prop shaft
2) get new small filter and replace the one I have
3) drain carb
4) purge filter and reprime carb

see if it helps.
thanks
ken

**Marian Claire** · 06-28-2011, 12:10 PM

Ken: What are you doing during " play long enough"? Adjusting throttle, choke, nudging in and out of gear? Dan S/V Marian Claire

**David Masury** · 06-28-2011, 02:15 PM

Just for chuckles, I would check the compression... if the engine has been sitting for a while, you may have a valve or two hanging up and you are not getting full power.

David

**KenVoodoo** · 06-28-2011, 02:31 PM

in answer to the last two posts: playing means exactly as you say, trying permutations of the throttle and choke as I put it in gear. Did this twice, once before the sail and once after. Can't say exactly what helped the second time (after the sails were down)...I suspect having the boat moving at 5 knots under sail was a great help the first time.

In answer to the second. I put a new head gasket on last week, and checked compression after that.. had 90-95 on each cylinder. That isn't to say it isn't a problem now. I have retorqued the head at least 3 times, probably should do again after another couple of hours of run time (as an optimist).

thanks
ken

**sastanley** · 06-28-2011, 03:03 PM

Ken, keep the details coming..did not realize you'd done all this other work...all the little things help to paint the big picture.

new gas = good - did you drain and clean the lines & tank & pump as well? There could be residual deposits.

new filter element = good idea, there could be old gas left in there & garbage getting by that too.

Keep at it.

**KenVoodoo** · 06-28-2011, 03:28 PM

Not sure you want to know everything I did in the last two weeks, but
1) drained tanks, cleaned line from cutoff valve to carb, cleaned old perko filter, flushed fuel pump, added new filter between pump and carb, removed carb and cleaned (twice). Did not clean tank, I am sure it was a mistake, but wasn't sure how to do it in place and I am still trying to figure out what to do with the gas I took out of it. Hoped the extra filter would take care of that. I strained the gas as it came out of the tank, and there was particles in it, but not extreme.
2) Changed distr cap, plugs, points, (not condenser...not sure why not). rotated distributor to find max rpm....probably should do this by a better method. Getting a diagnostic tool I used to have for my Corvair sent up to help with this.
3) At one point valve in cylinder 4 was sticking open, took off head, took off exhaust manifold (and carb again)with mystery oil got that working, put new head gaskets on, the new "good" kind, put it back together. Idled OK now, but always with alittle choke on. Could put it in gear on land.
3) Once launched engine same issue with choke, but went into gear OK.
4) played with idle mixture (from forum thread) got idle working great, stopped the stuffing box from flooding the boat.
5) where I am now........

ALso chasing down a small antifreeze leak (still haven't found), changed the FW impeller,

and don't get me started on plumbing a holding tank onto my Lectrasan.....

Maybe I should be near the boat more than 8 weeks a year.....
ken

**Marian Claire** · 06-28-2011, 04:52 PM

More questions: So before step 4 the engine ran with a little choke and would go into gear without bogging down? Is that correct? Dan S/V Marian Claire

**KenVoodoo** · 06-29-2011, 07:55 AM

First, in answer to the last question, yes.

More importantly, thank you for all your help. Last night I went to the boat, there were about 50 drips/minute from the stuffing box (but not a stream...I am going on the boat every day so not a big deal), so I just went ahead and tried it. Worked perfectly.

However I think the problem was a combination of fuel and the stuffing box, as out of about 15 minutes of running the engine, there were a couple of times it sounded like it the fuel was being interrupted, but then came back.

I will go ahead and change out the filter, and drain the carb in the next couple of days. My problems will probably still remain until I can really clean the tank, but it is usable now.

thank you
ken

stall when go into forward

stall when go into forward

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