really hard cold start

[medicineman]

Did you pull the idle and HS jets for a visual?

Often, these jets have orifices that go sideways and simply looking thru one end won't cut it...

Each jet should be pulled, initially check to see if light can be seen thru it, then cleaned.

You'd be surprised how much varnish can build up in those very, very small holes..

yes i did. was very careful on that. i use a welding tip orifice cleaner to clear all holes.

[panasonic]

Are there adjustable floats on those carbs?

[Masdenson]

What's the remedy if that's the case by the way? I'm having the same issue, but I found a start procedure that works, for now at least.

[panasonic]

I wonder if you have a bad or sticking float needle valve in one or more of your carbs....not shutting off the fuel and flooding the engine before you try to start it.

Does the primer ball take a long time to get hard?

A little test you can try. Get the thing running, if you can, let it warm up to operating temp. Now shut it down with kill switch. Pinch off the fuel line close to carbs so there can be no more fuel getting to the carbs. Let cool and and try and start again with fuel line still pinched off.....see if it starts any better.

[medicineman]

ok.....i got my problem fixed. rookie mistake----i did not remove the metal plate on top of the carburetor and clean under it as my carb breakdown picture looked like there was just a gasket under the metal plate. there are two round disks to remove and under one of them, the one where the carb adjustment screw screws in, there is an area with three tiny holes that needed to be cleaned. once i did that and reassembled it fires right up. Thanks for all the suggestions everyone.

[boscoe99]

Thanks for the update. Glad you found the problem.

Usually something simple. Simple to fix but hard to find.

[pstephens46]

Thanks for the update. Glad you found the problem.

Usually something simple. Simple to fix but hard to find.

Anybody got a pic/diagram of this spot he refers to? Will help my ignorant ass and perhaps the next guy as well. Every time I log in I am shown there are over 100 visitors. Only a couple dare post. Why so shy?

[walleye1]

It is a s/steal plate on top of the carb you have to take off to pull the rubber plugs and s/steal covers off to clean under them.

[medicineman]

Anybody got a pic/diagram of this spot he refers to? Will help my ignorant ass and perhaps the next guy as well. Every time I log in I am shown there are over 100 visitors. Only a couple dare post. Why so shy?

I did not take a picture, but i will try to explain better. on the top of the carburetor there is a metal plate with two phillips screws holding it on. under the plate there are some round disks----three sets as i recall. two of the sets just pop off, one set has a rubber o=ring on top that must be picked off first. remove all the disks, and underneath one of them, the one above the carburetor adjustment needle, there are some tiny holes that need to be clear. i used a welding tip cleaner and roded those holes out, blew thru the other two orifices i had exposed by removing disks with carb cleaner, and reassembled. made a big difference for me! i mistakenly thought by removing bowl and cleaning out the two jets in it i had opened everything up.

[99yam40]

good to here you got it taken care of, but it sounds like those were the idle and off idle ports.
I do not see how that would keep the choke from giving enough fuel to fire up

we hear it all of the time that the carbs were cleaned, but it ends up they were not done well enough

[medicineman]

good to here you got it taken care of, but it sounds like those were the idle and off idle ports.
I do not see how that would keep the choke from giving enough fuel to fire up

we hear it all of the time that the carbs were cleaned, but it ends up they were not done well enough

I think that fuel flow is restricted if those ports are not cleaned===it would be the same as screwing the fuel needle in more. that is one area of carburetor that is different than lawn mower carbs, etc. that i am used to working on. breakdown pictures of the carburetor do not do it justice----at least the ones i have seen----to see what is under that top plate and to understand it must be cleaned also. thanks for all the help!

[panasonic]

[panasonic]

1987 70 68.pdf

Much bigger PDF file

[99yam40]

As I said before , it seems that cover dealt with the idle and off idle ports not the main jet where the choke would suck fuel out of for start up,

but then that motor would never have idled properly if those passages under that plate were plugged up

[medicineman]

As I said before , it seems that cover dealt with the idle and off idle ports not the main jet where the choke would suck fuel out of for start up,

but then that motor would never have idled properly if those passages under that plate were plugged up

you have much more experience than I, however, that is the only thing i did different on my third attempt and when I reinstalled the carbs it fixed my cold start issue. the engine was idling fine once i got it cranked and it ran for a couple of minutes before my third cleaning attempt. seems to run fine now all the time-----at least on muffs. will be a few months before the real test of being on a boat takes place!