Link and Sync

asm_

Petty Officer 1st Class
Joined
Apr 11, 2010
Messages
245
Hi all,

As I'm studying all the information I can find about performing link and sync procedure, I noticed some instructions involves running the motor in gear, wide open throttle when setting max advances. Is this really necessary? Couldn't the same thing be accomplish by manually set the throttle level to full open and cranking the motor without fuel line connected? I just don't see how it is possible to run my boat, full throttle across the lake while watching the timing light on flywheel.

Thanks

B
 

dbrew

Seaman Apprentice
Joined
May 24, 2010
Messages
41
Re: Link and Sync

two things first you can run rabbit ears with a hose i dont like running it for very long like this and make sure it is in nutural or you might need a new foot. second you should be able to adjust it without running it you might need to do some minor tweaking. what does your manual say, it should give you all the specs. also is the engine running rough, what are you hopeing to accomplish.
 

huntin dawg

Petty Officer 2nd Class
Joined
Nov 12, 2009
Messages
197
Re: Link and Sync

Sync procedure should be performed with the motor not runnung using an ohm meter and a dial indicator.

What motor do you have? I will email the procedure to you if you PM me your address.

HD
 

sschefer

Rear Admiral
Joined
Nov 13, 2008
Messages
4,530
Re: Link and Sync

What motor are you working on? The procedures vary from engine to engine and often year to year.
 

asm_

Petty Officer 1st Class
Joined
Apr 11, 2010
Messages
245
Re: Link and Sync

One motor I'll be working on is Mercury 115HP inline 6. Made in 1982. Another one is a 1974 Thunderbolt 850

I haven't have need to do a link&sync yet. However, I'm just curios to see how it is possible to perform link&sync @ WOT.

B
 

asm_

Petty Officer 1st Class
Joined
Apr 11, 2010
Messages
245
Re: Link and Sync

bumpy bump!!!

May be someone have more information on this topic. :)
 

saumon

Lieutenant
Joined
Aug 2, 2004
Messages
1,452
Re: Link and Sync

If you don't have a OEM service manual, get one asap! WOT timing is set at cranking speed (3000 rpm) with leads grounded. If you were alone, you'll have to jump the starter while holding the timing light. And never ever run it past 2000 rpm in a barrel or, worst, on muffs.
 

arsenalpsu

Petty Officer 1st Class
Joined
Dec 1, 2008
Messages
290
Re: Link and Sync

timing is set at cranking speed. Your primary pickup is 5-7 ATDC and your cranking is 20 BTDC (which is 18 at real WOT) this is for your 115hp, not sure on the other.

What you need to adjust in the water is your Idle screw. If you are reading that "Link and Sync" post by Clams (wayne) it is very clear on this fact and you need to re-read it as you got something wrong.
 

sschefer

Rear Admiral
Joined
Nov 13, 2008
Messages
4,530
Re: Link and Sync

If you don't have a OEM service manual, get one asap! WOT timing is set at cranking speed (3000 rpm) with leads grounded. If you were alone, you'll have to jump the starter while holding the timing light. And never ever run it past 2000 rpm in a barrel or, worst, on muffs.

Saumon, you really don't need to time at 3000 RPM. 300 will do, all you need is enough spark to trigger the timing light. I think the 3000 RPM number is the number thats used as the in gear RPM and is an indication of when the timing advance should be full in. It's certainly measurable at the at point but not practical to do so.

Since it's a purely mechanical adjustment, you can set WOT timing at 300 RPM. I use a remote starter switch and sit on my transom in a dimly lit area.. Wait until after the sun goes down or seeing the light will be difficult.
 

saumon

Lieutenant
Joined
Aug 2, 2004
Messages
1,452
Re: Link and Sync

I think the 3000 RPM number is the number thats used as the in gear RPM and is an indication of when the timing advance should be full in.

Sorry if didn't explained it well but you're right, this is what i mean. Full advance timing isn't really practical to set, as i don't really picture me sitting on the transom with a timing light at WOT on the lake ;). For my particular engine, for example (60hp mid-90's 2-stroke), the max advance @ 5000rpm is 22deg BTDC but can be set at 24deg BTDC @ cranking speed.
 

asm_

Petty Officer 1st Class
Joined
Apr 11, 2010
Messages
245
Re: Link and Sync

sschefer. I am glad you chimed in!!

After reading the 3000RPM cranking speed, I was still scratching my head trying to figure out how to the hack am I going to get my starter to crank that fast. :eek:

300RPM it is then. Thanks!!
 
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