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25 hp Honda cold start trouble

H

htbboats

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Working on a 25 Honda carb model that has the enrichment starting system. Ive been told that it must face {wiring} towards the front of the motor or it ineffective? Tried that with no luck. If I barely manually prime it it starts just fine, runs fine. Anyone got any help out there?
Thanks...Boathead
 
The operation is not affected by which way the wires go...it is just that they are routed properly if they go forward.

There is most likely a blockage in the starting circuit of the top carburetor; your bystarter is stuck expanded; or you need a different fuel bowl and bystarter in the top carburetor.

Check out this thread (although it is on a 30HP - same basic motor). Although he is having an issue with running rich....it does show pictures of what the bystarter should look like in three different stages.

Post your frame serial number and the lettering on the top of your bystarter, and I will check to see if changing the bystarter and bowl will help your starting.

Also....when you start the engine, the throttle should not be advanced (like you had to do on two strokes).

Mike
 
First of all thanks for tuning in to try to help me out.
The information on the motor, bystarter lettering is hewan/70 on the bowl. BATJ-1301148 on the motor.
History as I know on the motor is it sat up for some time. Carbs were pretty bad. I ran them thru several cycles in a ultrasonic cleaner. It starts well and idles well if I hand choke it or inject a small amount of fuel in the carbs. Seems a little rough at first but after a few seconds smooths out just fine.
I got the information about the direction of the bystarter from a Honda dealer. I did not really swallow that but I did try it.
I am a 30 year Merc dealer. Maybe I should stick to what I'm supposed to know?
Thanks again
 
You have the most current bystarter and bowl.

Before you take the carbs back apart....

Did you vacuum balance the carburetors? That is important to do to these Hondas. When you do, you will need to clamp off the vertical hoses running between the outside of #1 to #2 and #2 to #3. You also have to clamp off the smaller hose running accross the top of the #1 (top) carburetor.

Once you clamp them off while the motor is running, you will probably have to readjust the idle stop to get it to idle 950 plus/minus 50. I like to set it on the higher side. Make sure that you make the adjustment with the engine warm (but after 30 years, you probably know that).

Once you balance it and remove the clamps, the idle will go up....so you will have to readjust.

When you try to restart, be sure that the fuel bulb is hard and the throttle is all the way down.

If that does not improve it, then go back to the top carburetor and pay close attention to the bowl and all its passages. The extra fuel for starting is picked up by the narrow tube going up to the bystarter. Make sure the tube is clean and when you fill up the bowl with solvent, the hole in the bowl where the tube goes into should have fuel in it. If not....more cleaning is involved or sometimes just get a new bowl.

Mike
 
I did vaccum balance the carbs but did not clamp the hoses as you suggest. I'll get back on it Monday and see how it goes.
Have a good weekend!!
 
Bingo!! After thinking about all your suggestions over the weekend I decided to go ahead and remove the top carb and check and check that passage. There is where the trouble was. I should have been paying closer attention! I should know better!
Just want to give you a "pat on the back" for helping me! Thanks again and have a Great Day!
 
Glad you got things worked out. Don't forget to recheck the carb balance....it makes a big difference at idle and acceleration.

Mike
 
The source of the trouble was the passage from the bowl to the cavity where the enrichment gets its source of fuel. I had run the carbs in a ultrasonic cleaner thru several cycles, blew out that passage I thought but really never checked to make sure it was clear. Rookie mistake!!! Went back and checked and found the trouble. I managed to get it clear and made sure fuel would flow thru it by putting fuel in the bowl area and watching to see that it also filled the enrichment cavity
 
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