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D.U.I Ignition timing question

Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=50644
Printed Date: November-22-2024 at 7:27pm


Topic: D.U.I Ignition timing question
Posted By: MonsterSkier
Subject: D.U.I Ignition timing question
Date Posted: May-24-2022 at 12:55pm
Hey, I’ve just swapped my ProTec Ignition with the D.U.I set-up using JPASSes write down.

My Boat is a 1992 Barefoot Nautique (Excel) with the PCM 351 HO.
Firing order is 13726548.

The Dizzy is installed, true TDC found and the harmonic balancer set to 10 degrees before TDC. Terminal of Cylinder #1 is now pointed at the finger to make sure timing is advanced somewhere at 10 degrees for first startup.

I haven’t started the engine yet because I am confused by the angle my dizzy is showing, compared to the angle of other members here.

Can somebody confirm that my dizzys angle is right or that I am doing something wrong? (D.U.I states that there is no specific terminal to be used as cylinder #1. I have chosen the terminal that is pointing at cylinder #1)

Thank you!

https://ibb.co/sCRh4rp" rel="nofollow">

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98 Ski Nautique 196 (current)
08 Mastercraft ProStar 197 (current)
88 Ski Nautique 2001 (sold)
92 Barefoot Nautique (sold)
01 Ski Nautique 196 (sold)
93 Ski Centurion Tru Trac III (sold)



Replies:
Posted By: TRBenj
Date Posted: May-24-2022 at 1:56pm
Distributor orientation is inconsequential. You’ll need to make sure you’re at TDC on the compression stroke, else you could be 180 out.


Posted By: desertskier
Date Posted: May-24-2022 at 2:16pm
Here is mine.  Looks close to what yours is.




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92 SN - Owned since 93
99 Pro Air
89 SN - Went to live on a lake in Texas
75 Donzi 16 - Sold in 93


Posted By: mosinee77
Date Posted: May-25-2022 at 8:13am
The orientation means nothing, just make sure you are on the compression stroke, or the timing will be 180 degrees out.

With your initial at about 10 degrees the engine should fire easily.


Posted By: MonsterSkier
Date Posted: May-26-2022 at 10:23am
Big thanks to everyone of you!
Started the boat up yesterday and it did start on first turn (also first start of the season). I guess turning the engine by hand helped priming the carb bowls.

Here is a video of the success!
https://www.youtube.com/watch?v=YC1Uf3owy1g" rel="nofollow - https://www.youtube.com/watch?v=YC1Uf3owy1g

Now I only have to figure out the knock that I am getting from cylinder #2 or #3. Did notice it first after renewing the valve stem seals last summer. Thinking of either bad exhaust manifold gasket, rod knock or a lifter problem. 

I did pull the spark plug wires one another last year and am remembering it becoming much quiter when spark plug wire of cylinder #2 or #3 was pulled.
https://www.youtube.com/watch?v=y7IuHm4Bi_s" rel="nofollow - https://www.youtube.com/watch?v=y7IuHm4Bi_s


-------------
98 Ski Nautique 196 (current)
08 Mastercraft ProStar 197 (current)
88 Ski Nautique 2001 (sold)
92 Barefoot Nautique (sold)
01 Ski Nautique 196 (sold)
93 Ski Centurion Tru Trac III (sold)


Posted By: Bamanautique91
Date Posted: May-26-2022 at 11:58am
Beautiful boat!.. Sounds great.  I have the same color scheme on my 91 SN

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Ryan

91 Ski Nautique
Huntsville, AL


Posted By: MonsterSkier
Date Posted: June-05-2022 at 4:34pm
What would be the correct timing when the engine is idling?

Mine is static set at 10* before TDC. When the engine is idling at around 750rpm timing is at 12*.

There is a sticker in the engine compartment that calls for 10* static, 18* at 700rpm and 30* at 3600rpm.

Do I leave it at 10* static or should I adjust till I get 18* when idling?

-------------
98 Ski Nautique 196 (current)
08 Mastercraft ProStar 197 (current)
88 Ski Nautique 2001 (sold)
92 Barefoot Nautique (sold)
01 Ski Nautique 196 (sold)
93 Ski Centurion Tru Trac III (sold)


Posted By: KENO
Date Posted: June-05-2022 at 7:56pm
Leave it right where you have it and check the timing at 3000 plus rpm and you should have somewhere between 32 and 36 degrees total.

The sticker was for the ProTec system which controlled timing electronically and could do things electronically like give you a certain amount of advance at any speed and load based on inputs to the computer  and make an advance curve that a set of flyweights and springs can't duplicate.

DUI says it has 24 degrees of advance on top of your initial setting. People around here seem to get somewhere between 20 and 24 when they check it.

Not knowing what your gas is like over there, 10 to 12 at idle is a good starting point


Posted By: MonsterSkier
Date Posted: June-06-2022 at 2:30am
Thanks Ken!

I will leave it where it is and and check the timing at 3000+ rpm when I am at the boat next time.

Fuel quality here is decent. I use 95 octane with a max. of 5% ethanol in it.

Only downside is the current price with almost 8$ per gallon…

-------------
98 Ski Nautique 196 (current)
08 Mastercraft ProStar 197 (current)
88 Ski Nautique 2001 (sold)
92 Barefoot Nautique (sold)
01 Ski Nautique 196 (sold)
93 Ski Centurion Tru Trac III (sold)


Posted By: MrMcD
Date Posted: June-06-2022 at 3:04am
For top performance it is good to know what your timing is at idle and when the advance comes in plus where it stops advancing and how much advance you have when it stops advancing.

If you watch your timing marks as you raise the RPM you should see a nice advance curve that is smooth and does the exact same thing every time you raise the RPM's.   As noted the DUI may show you advance total between 20 and 24*.   You need to know what you are getting to get the best performance.  
As you watch the timing advance pay attention to the RPM.  Somewhere between 2,800 and 4,000 it will stop advancing and your timing will stay the same as you raise the RPM higher.  Most refer to this number as Total Advance.   So once you know your total and at what RPM it is fully advanced you can tune your base timing setting.   If as mentioned you get 20 or 24* advance and you want 32-36* Total you determine your base timing from the difference.   If you want 36* Total, and the distributor gives you 24* advance at 3,200 you would set your idle at 12*.  12 + 24 = 36 Total, and you are good as long as the boat runs well at 12* at idle.  The Total advance # and a smooth advance curve gives you your best performance and power, the base timing # really only affects your idle   Having too much Total timing will move you into detonation and that can rob power or damage an engine so don't get carried away.  If it runs outstanding at 34, great, if you try 36 and it starts to ping or the power lays down at top speed back it off.  There is no perfect number for all 351W engines, your compression, fuel quality, Octane, fuel mix, Lean or rich, all affect how much timing your 351W will run best at.


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Posted By: KENO
Date Posted: June-06-2022 at 6:55am
Originally posted by MonsterSkier MonsterSkier wrote:

Thanks Ken!

I will leave it where it is and and check the timing at 3000+ rpm when I am at the boat next time.

Fuel quality here is decent. I use 95 octane with a max. of 5% ethanol in it.

Only downside is the current price with almost 8$ per gallon…

Your 95 octane gas is about the same as our 89 or 90 octane gas here in the USA. A  mid grade of gas.

The number difference is due to how it's rated over there.

We're just kinda strange over here and use the Research + Motor /2 rating  method while most of the rest of the world just uses the Research number. The posted pump numbers over here are R+M /2

Could put a long explanation here but there's plenty of info on the internet Wink

You'll probably be happy in the 32 to 34 range for your total advance.





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