fastwin 18 coughing and dying...again...

[hawk232]

well the problem started again. here is my original thread http://forums.iboats.com/showthread.php?t=436814

i decided to summarize what was accomplished in the last thread.

rebuilt carb with omc kit, everything was clean to start, cleaner when finished
new plug wires
compression 100psi to 95psi bottom
adjusted amature retaining ring to tighten plate up
link and sync

last time the problem seemed to go away when i did the link and sync, as it was out of adjustment.

today it fired right up at the launch, idled out for about 60 seconds and started coughing (at like 1/16 throttle), dropped it to idle speed and it still coughed on occasion, i richened it up (thinking the ride may have tightened it up a little) and it got a little better. i gave it some throttle and it died. tried to crank it up and I am now back to square one. when i finally get it running it only runs for a few seconds before it coughs so bad that it dies. it seems to cough the worst at about 1/16 throttle. also, i tried to rev it up and it sounded like it was flooding out, and died. i already have an ignition tune up kit on the way, i ordered it a few days ago. I am asking for two things here:

1) talk me out of using it as an anchor for my formula.
2)any ideas?

 

[oldcatamount]

Re: fastwin 18 coughing and dying...again...

The "coughing" could be a sign of reed valve problems or, it may be adjusted too lean. Aso check the fuel line all the way to the tank. An air leak caused by a small crack or a loose clamp can screw it up to. (Is the tank vented?)

 

[jbjennings]

Re: fastwin 18 coughing and dying...again...

Take out the fuel filter from the glass bowl and run it without the fuel filter in and see what happens.
JBJ

 

[hawk232]

Re: fastwin 18 coughing and dying...again...

the tank and line is brand new, and vented. I will check it for cracks just in case! I am positive that it is not adjusted to lean because while you were typing that I was out fiddling with it and I adjusted it far richer than it should be 2 1/2ish turns out and it made (seemingly) zero difference

jbj- you must have esp'd that idea to me, while i was out there fiddling I pulled the filter out and ran it. it seemed to have fixed it, but I kept it running to just make sure. sure enough a little while later is was back to the same old shananigans...

i am forming a strong dislike for this engine!

 

[oldcatamount]

Re: fastwin 18 coughing and dying...again...

Have you checked the fuel pump at all? Disconnect the fuel line from the carb side and crank the motor over, you should see fuel squirting out (not a lot but, steady)

 

[hawk232]

Re: fastwin 18 coughing and dying...again...

i had not previously checked the pump. i just did. when cranking, it pulses fuel out of the barb ~3/4"-1". I assume that means that its good?

 

[oldcatamount]

Re: fastwin 18 coughing and dying...again...

Yup, your pump is working Ok. Sooo...the next thing to look at is the ignition, points, plugs, coils. Sometimes a coil that is going bad will be OK for a few minutes and then start to give you intermittant fire and result in the symptoms you described. (don't give up just yet)

 

[hawk232]

Re: fastwin 18 coughing and dying...again...

well i replaced the plugs earlier and the problems seems to have gone away. i remain hesitant though, as this is the third time that i have "fixed" the problem! points and condersers are on the way, all thats left after that is coils, im almost there lol

i am going to go run it a while tomorrow and see how it acts...

as always, thanks a ton!

 

[jbjennings]

Re: fastwin 18 coughing and dying...again...

Hawk,
I thought you'd replaced the coils for some reason.....
Intermittent spark could definitely cause the problems you're having, and coils are the only weak link on your motor. WHen they're replaced and working right, the fastwins are real jewels. THere should be absolutely no coughing after they get warmed up after a few seconds of running. They should purr very smoothly at all speeds when they're tuned right.
Later,
JBJ

 

[cougar1985]

Re: fastwin 18 coughing and dying...again...

if you have never changed the coils or the p.o. never did either id bet money on the coils being shot !if they have discolouratin or any cracking atall their toast.ive seen the coils so bad you could crush them with your hand but the motor still fired and ran, though poorly.send pic of coils if you can or just be safe and put in new ones,then you know for sure their good.

 

[hawk232]

Re: fastwin 18 coughing and dying...again...

the coils look perfectly fine, thats why they havent been replaced yet! there are no cracks or discoloration at all. however, i was recently informed (i think by jbj) that they could still be bad even though they look ok to the eye. one is green and one is black for what its worth.

I am thinking that i am just going to order some new ones and be done with it.

 

[oldcatamount]

Re: fastwin 18 coughing and dying...again...

the green one is the newest one

 

[lindy46]

Re: fastwin 18 coughing and dying...again...

Check coil resistance to see if they are ok. Here's some good info from another website:
"Using a Ohm Meter or Diode Continuity Checker test the continuity of the primary windings of the coil. There should be continuity between the Green and Black leads. There should be about .9 ohm resistance between the Green and Black leads. Next test the secondary windings of the coil by measuring the resistance between the Black lead and the spike for the spark plug wire. I measured 7.64 thousand ohms. Your measurement will not be exactly the same but the point is, you should be able to measure the resistance of the primary and secondary windings."
Here's the url:
http://www.outboard-boat-motor-repa... 5.5 HP 1954-1964 Ignition System Tune-up.htm

 

[hawk232]

Re: fastwin 18 coughing and dying...again...

well replaced the coils, points and condensers.... still doing it... its about to sit for a long long time, im burnt out on bad boating trips! time to take one of the other boats out!

 

[samo_ott]

Re: fastwin 18 coughing and dying...again...

Give it to JBJ, he's just up the I49 from you!!!

 

[hawk232]

Re: fastwin 18 coughing and dying...again...

ok, so now it has new plugs, wires, coils, and points... what the heck else could it be!?!?!?

 

[54fleetwin]

Re: fastwin 18 coughing and dying...again...

I though someone mentioned for you to check the reeds? Did you?
Leaky reeds will cause carb reverbsion

 

[kbait]

Re: fastwin 18 coughing and dying...again...

Did you replace the fuel line from the filter to the carb? Ethanol in fuel can dry out the inside and it can slough away and clog the carb, or jam the float valve open. Frustrating occurence when you just re-installed a freshly cleaned carb. (been there..). Good luck!

 

[hawk232]

Re: fastwin 18 coughing and dying...again...

I have not replaced the lines, but i pulled them off and looked through them and all seems to be fine. I am getting sick of throwing money at it though... im sure yall know what I mean!!

How would I check the reeds to make sure they are in decent shape? in terms of actually looking at the reeds... i know how to get to them.

 

[54fleetwin]

Re: fastwin 18 coughing and dying...again...

you need to check if the reeds fully seal, they are a check valve, if they do not seal, the piston on the down stroke will push fuel charge back through and out the carb