Association Forum - outboard motor

Assn Members Area · Join

Home.

Association Forum

Ships Store

Cruising

Racing

Technical Tips

Photo Gallery - New

Boat Search - Updated

Manuals & Brochures

Swap Meet

Links

Officer Flag Line & Staff

Bylaws & Constitution

Members Area

Join the Association

Notice:
The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.

Association Forum

Username:	Password:
Save Password
Forgot your Password?

All Forums

Catalina/Capri 25/250 Sailor's Forums

General Sailing Forum

outboard motor

New Topic

Topic Locked

Printer Friendly

Author

Topic

gerdo
Navigator

Member Avatar

107 Posts

Initially Posted - 08/05/2002 : 10:27:00

I have an old (1987) honda four stroke long shaft 8 HP outboard. It will not hold a low idle. I lost count of how many times it dies about 5 slips from ours. Usually have enough way to make it in. I have replaced fuel lines, including the hose from tank to motor, new fuel lines in motor, new fuel filter. It runs at high idle but when you drop it to shift it dies. I have tweaked the carb adjusting screws. Have not rebuilt carb yet, and am considering that it might be fuel pump. DOes anyone have any experience with this? It breaks my heart to think I may need to spend $2500 for a new motor. Will try to fix first.

Edited by - on

Douglas
Master Marine Consultant

Members Avatar

1595 Posts

Response Posted - 08/05/2002 : 12:01:52

So whats the problem with taking it in to a Honda dealer for a tune up. $75 to $85 dollars is a lot cheaper than a new engine. BTW I bought my 1999 8hp with 25 hours on it for $1400

Doug&Ruth
Wind Lass
Tacoma Wa.

Edited by - on

Leon Sisson
Master Marine Consultant

Members Avatar

USA
1893 Posts

Response Posted - 08/05/2002 : 12:20:18

gerdo,

I can think of several things that might cause the symptoms you describe. By far the most likely would be a dirty or clogged idle fuel jet in the carb. Hondas, Yamahas, and probably all the 4-strokes have incredibly tiny idle fuel metering orifices. It doesn't take much at all to stop one up. I used to have this problem a lot. Then I started running all the fuel out of the engine at the end of each trip. Since then, I can't remember having to clean a fuel jet. Even if you usually take your engine to the Honda shop for everything, it might be a good idea to learn how to clean out a contaminated fuel system by yourself, even out on the water. A couple of times that's saved me from needing a tow.

-- Leon Sisson

Edited by - on

gerdo
Navigator

Members Avatar

107 Posts

Response Posted - 08/05/2002 : 14:23:12

Thanks Leon. It has been a long time since I worked on carburators. Although I just bought a used lawn tractor that lost its exhaust deflector and melted all the plastic on the carb. Went to store and bought parts, put it back to gether and away it goes. I do all my own mechanical work including engine rebuilts so eventually I will conquer this. There are three screws on carb. One is a stop that the throttle control hits. Second is the adjustment screw, you know the one you tighten then back off 2 and one half turns. The third is flush with the top of the bowl, no spring under it, it is tight. Which one is the idle fuel jet? To clean do you remove the screw and spray carb cleaner in the hole?

TO Doug and Ruth: You got a good deal on your motor. Here on the east coast, specifically on the chesapeake things are much more expensive.

Edited by - on

John Mason
Admiral

Members Avatar

USA
687 Posts

Response Posted - 08/05/2002 : 15:05:47

I had a similar problem with my Honda 7.5 4-stroke (mid 80's). I took it to the Honda dealer, it was a dirty carb. Cost me $37 and it runs great again.

John Mason - Ali Paroosa
1982 - FK/SR #3290

Edited by - on

Leon Sisson
Master Marine Consultant

Members Avatar

USA
1893 Posts

Response Posted - 08/05/2002 : 23:05:56

gerdo,

<BLOCKQUOTE id=quote>quote:<hr height=1 noshade id=quote>The third is flush with the top of the bowl, no spring under it, it is tight.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote>I don't know what that one would be.

<BLOCKQUOTE id=quote>quote:<hr height=1 noshade id=quote>Second is the adjustment screw, you know the one you tighten then back off 2 and one half turns.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote>That's probably the one you're looking for.

<BLOCKQUOTE id=quote>quote:<hr height=1 noshade id=quote>To clean do you remove the screw and spray carb cleaner in the hole?<hr height=1 noshade id=quote></BLOCKQUOTE id=quote>In your dreams.<img src=icon_smile.gif border=0 align=middle> You'll probably first have to "ream" it out. Be very careful not to scratch the sides of the invisibly small metering hole, or enlarge it, or do anything else that would alter its flow characteristics. I usually start by stripping the insulation off a few inches of thin gauge finely stranded copper wire. Next, I separate out one of those strands. I then use that soft thin wire to gently break up the plug of dirt in the fuel metering jet. Then you can use your snorkle equipped spray can of miracle carb cure to verify that the idle passages are no longer completely blocked, and finish rinsing out the scum you've now loosened.

The following picture illustrates a typical idle fuel route through a mid-80's Honda 7.5-10HP carb:
<img src="http://www.trailersailor.com/uploads/honda_carb_04.gif" border=0>

If you need more procedural info you're welcome to give me a call (321-)784-8406.

-- Leon Sisson

Edited by - on

gerdo
Navigator

Members Avatar

107 Posts

Response Posted - 08/06/2002 : 10:29:34

thanks again Leon. The diagram is differnt than the top of this carb, but I will work through it. Also will take your advice of running fuel out of motor. I do not trailer mine it is in the bay for 9 months a year, then dry stored. So working off the transom is a little tough but I will manage. If I have to pull motor, have never pulled motor while it is in water. Any good ideas how to avoid hernia or dropping it.

Edited by - on

B.Jones
1st Mate

Members Avatar

39 Posts

Response Posted - 08/06/2002 : 13:42:22

Just dropped my '80's model Honda 10 hp off at Honda dealer today at lunch for the exact same problem. I will let you know what the problem was. My boat stays in water all season too so I had to remove the motor while in the water. Backed into slip (neat trick with inoperative motor) as close to dock as possible then lifted off. Doctor says I can take the back brace off in about a week.

Edited by - on

Leon Sisson
Master Marine Consultant

Members Avatar

USA
1893 Posts

Response Posted - 08/06/2002 : 14:03:42

gerdo,<BLOCKQUOTE id=quote>quote:<hr height=1 noshade id=quote>The diagram is differnt than the top of this carb,<hr height=1 noshade id=quote></BLOCKQUOTE id=quote>The carb in my picture is upside down; that's how you work on them. Could still be different though.<BLOCKQUOTE id=quote>quote:<hr height=1 noshade id=quote>Any good ideas how to avoid hernia or dropping it.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote>Yes. I just did this with a Yamaha 10HP elec.start x-long. As B.Jones suggested, back into a slip. Get the motor mount as close to a tall piling as possible. Tie a safety line from the motor handle to high on the piling. Rig another line as a lifting handle (sort of an inverted thong bikini bottom tied tight around the cowl of the motor). Wear a back brace to lift so you won't be wearing one for two months afterward. Have a spotter handy in case the weight does something unexpected.

For carb work, I just lean over the transom to remove the carb, then take it to a more safe and convenient location to tear into it. If you're really concerned about dropping stuff overboard, I've heard of people using a square crab net hung under the motor to catch any pieces that try to escape.

If you find ANY contamination in the float bowl, you have to remove ALL of it, even if it seems to be well attached at the moment. A flyspeck sized piece of dirt can cause the problem you described. If you don't already have one, this would be a good time to install a serious fuel filter.

-- Leon Sisson

Edited by - on

gerdo
Navigator

Members Avatar

107 Posts

Response Posted - 08/06/2002 : 16:24:38

thanks B Jones. Will await your diagnosis. And thanks Leon I will pull carb next week and take home to clean and blow out with air.

Edited by - on

Todd Frye
Navigator

Members Avatar

USA
222 Posts

Response Posted - 08/06/2002 : 17:55:25

Took my 7.5 Honda to the shop in 2001, because I figured the pro's would do a good job. The outboard never seemed to run quite right through that season, but it got me out passed the break water. Took it home for the winter as a "things to do" project and noticed they put a carb gasket in wrong, blocking the butterfly valve. I invested in a shop manual, ordered new rebuild kit for the carb, and did the rebuild in 30 minuets. Carburators don't get much easier than this one. It runs great and now I know the engine better. Had a similar problem in 2000 to the poor idle mentioned before. Turned out to be the vent valve on the gas tank. I also noticed a broken casting on my pull cord housing, which is bolted down with 3 bolts over the flywheel. Anybody have a slick way to repair this? Todd Frye

Edited by - on

Topic

New Topic

Topic Locked

Printer Friendly

Jump To:

Association Forum

Notice: The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.