Link & Sync how to?

[EJ3]

I have a 1977 55hp Johnson. I am wondering how to do a link and sync. I don't know what it means or if I even need to do one.

Do I just need to make sure both plates in the carbs are closed and then tighten the 2 bars that link between the two together?

Probably a dumb question, but thanks for the help!!

 

[HighTrim]

Re: Link & Sync how to?

You should really invest in a service manual for your motor, it will honestly pay for itself a million times over. To assure proper spark advance at all throttle settings, your carb and timer must be synced after the timer linkage has been re assembled. You will need a timing light. What is making you think you need a linc n sync in the first place?

 

[EJ3]

Re: Link & Sync how to?

I am not even sure I need one!

Here is what the motor does...

It will run WOT right off the bat for a few seconds then the rpms will drop to 3000 accompanied with a "bogging" sound. If I take it to around half throttle, after a few seconds the motor's "sound" goes back to "normal" and I can throw it into WOT and the rpms will start to climb but then it boggs down again.

It never dies, but idle is a bit high, around 1500 rpm.

I have replaced both coils, both plugs, fuel pump and lines (except the line between the carbs). It has a brand new tank and line with primer bulb. I have cleaned the carbs, sort of, and replaced with a carb kit.

I don't think I cleaned the carbs very well since I didn't have any carb cleaning solution or air compressor. Now I have both and will be going through them again!

Do you think the carbs just need a GOOD cleaning?!?!?!?

 

[Gary H NC]

Re: Link & Sync how to?

Without compressed air its hard to actually get the orifices in the carbs clean.
Did you do a complete rebuild on them or just take the bowl off and clean a little?
Sounds like a carb or fuel restriction or its sucking air.
Will the primer ball pump up firm and hold?

 

[HighTrim]

Re: Link & Sync how to?

I agree with Gary, you will probably need to take the carb off again and re clean, setting it up as per your manual. Pay special attention to the high speed jet. Your idle is too high as well. Is it 1500 under load in gear? It should be more around 650 to 700 rpm. You may well need to clean out the carb, set the idle, followed by a link n sync. Try spraying some pre mixed fuel into the carb throat when it is acting up, or choking it out....does that improve things? Let us know what you find.

 

[EJ3]

Re: Link & Sync how to?

I had a carb kit and a can of compressed air!!! These carbs have fixed jets. I went out and bought an air compressor! The primer bulb gets hard and stays that way.

Any recomendations?????

Bumping the choke makes it want to stall

1500 rpm is idle in neutral and in the water not the hose

 

[reeldutch]

Re: Link & Sync how to?

First things first

how is your compression?
spark?
fuel?

could be vacuum leak

 

[EJ3]

Re: Link & Sync how to?

First things first

how is your compression?
spark?
fuel?

compression is 135 on each
spark is good
new fuel

 

[jtexas]

Re: Link & Sync how to?

there may be other problems contributing to your symptoms, but first make sure the carbs are squeeky clean inside & out. take out the core plugs & squirt some aerosol carb cleaner through all the passages. sounds like a cylinder dropping out occasionally - a miss-adjusted float can do that to ya.

if everything was fine before, and you haven't pulled the flywheel or messed with any adjustment screws you might can get by without a full blown link & sync. The throttle valves have to be parallel, closed at idle & horizontal (not beyond) at WOT, and the throttle cam (linked to spark advance rod) has to hit the roller (lower carb) on the mark.

the procedure varies a bit from motor to motor, a service manual really is a must...

 

[reeldutch]

Re: Link & Sync how to?

i would put the carbs back on after cleaning and setting the float according to service manual.

then i would test it again.

if the problem is still there i would take the air silencer of and spray a litle premix into one carb trought at the time.
see if it changes.

also when it happens you could shut the motor down imidiatly and take a look at the sparkplugs.
see if there is a difference in them wet or dry.

i believe you have air leaking in the system somewhere.
does the engine sneeze?
also may be vacuum.

i would get the pressure and vacuum gauge an a piece of clear vynil hose and test the fuel system.

 

[EJ3]

Re: Link & Sync how to?

- a miss-adjusted float can do that to ya

I will check that out when I am in the carbs. I have it adjusted to where the float is parallel to the top of the bowl.

No sneeze!

 

[HighTrim]

Re: Link & Sync how to?

Just to add the the comment about pressure testing the fuel system.

Get a vacuum gauge and hook it inline on the fuel hose before the engine, along with a clear section of hose. Take it for a spin, noting the readings and monitor the fuel flow through the clear hose.

Findings:

-Vacuum of less than 2 inches and air bubbles in the clear hose indicates an airleak into the fuel system
-No air bubbles and less than 2 inches indicates a bad fuel pump
-Vacuum over 4 inches indicates a restriction.

Sample gauge

"http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&sspagename=STRK%3AMEBTOX%3AIT&viewitem=&item=4610113711&_trksid=p3984.cTODAY.m238.lVI"

 

[EJ3]

Re: Link & Sync how to?

So I think I found the culprit!

I finally got some time to spend in the garage (you would be supprised how little a 3.5 month old daughter leaves you for free time!!)

Anyways, I took the carbs apart again and re-cleaned. Everything was pretty clean except the high speed jet in the top carb. When I held it up to the light there was only about a pin hole size passage. After I blew it out there was about the width of a big paper clip worth of a passage. I still blew everything else out and inspected. I also had a float that I adjusted a slight bit.

Ofcourse I have to wait 5 whole days to test it out, but none the less I can't wait. I think my problems are solved (fingers crossed)!

Thanks for all the help guys!

 

[Gary H NC]

Re: Link & Sync how to?

I hope that takes care of it.At least you did find something.The 1500 rpm idle in the water is too high.I hope you get that figured out too.Good luck!!

 

[EJ3]

Re: Link & Sync how to?

I have read somewhere on here that a fuel delivery problem can raise the RPMs. So I am hoping the "2 birds with 1 stone" applies here!!!

 

[rndn]

Re: Link & Sync how to?

You really should get yourself the service manual for the motor. It may have saved you replacing the parts that did not fix your problem. If you do buy one make sure you get the manufacturers manual and not one of the aftermarket ones. "http://www.outboardbooks.com/" supplies the service mauals if you're interested.