Twin 2016 Optimax 250hp (non xs) port engine startup/idle issue.

[barclayrl]

2B124142 port cxl - trouble engine


2B231519 starboard xl


Have a strange issue with my port engine, 2016 Optimax 250. During startup the engine starts with some violent shaking for a few seconds, shakes for a bit, then smooths out slightly. no longer hitting wot, cruise rpm sound fine but the idle has a miss for sure. Starboard engine sounds very clean on startup and just generally sounds better than port.

Here is a list of items I have replaced as part of routine PM, but still no change
Injectors flowed and cleaned at duck river marine.
New plug wires
Fuel/Air in range per gauge testing - within 10PSI of each other
Tracker valve replaced due to finding fuel in air rail, resolved fuel in air rail issue, but rough start/shaking still persistent.
New plugs after tracker valve replacement
Reeds visually inspected - black carbon fiber.
Coils swapped from starboard engine to verify
Compression within 3psi for all 6 cyl.
20210727_232304018_iOS.jpg

Any help on tracking down the culprit would be greatly appreciated.

[lpugh]

KV spark test required

[JOE54]

fuel psi bleed off test at key off / inspect and or replace pulse pump diaphram kit

[barclayrl]

What KV should the optimax coils output? just 30 or should 40 be tested as well?

[barclayrl]

fuel psi bleed off test at key off / inspect and or replace pulse pump diaphram kit

Do you have link to this procedure? If you mean the fuel rails, the PSI stays for a long time after shut down.

[lpugh]

What KV should the optimax coils output? just 30 or should 40 be tested as well?

.625 gap over 40 kv
You will need a dual glycerin filled gauge set 150 psi, read air and fuel pressures running and when shut off 5,10 & 15 seconds after shutdown, report back with results

[EuropeanAM]

Definitely get us some accurate air/fuel readings at the 5/10/15 seconds after shutdown. You can restart for each of these time periods.

Also look for other sources of unmetered fuel or oil getting into engine (overfilled oil tank, leaking diaphragms in pulse fuel pump, fuel leaks inside cowling, water in fuel sensor at IVST leaking, etc).

Please take a moment to review the Announcements at the top of the Forum, and be sure to provide the Required Info (serial number) when posting. Thanks!

[barclayrl]

Definitely get us some accurate air/fuel readings at the 5/10/15 seconds after shutdown. You can restart for each of these time periods.

Also look for other sources of unmetered fuel or oil getting into engine (overfilled oil tank, leaking diaphragms in pulse fuel pump, fuel leaks inside cowling, water in fuel sensor at IVST leaking, etc).

Please take a moment to review the Announcements at the top of the Forum, and be sure to provide the Required Info (serial number) when posting. Thanks!

I tried to read the rules and it says invalid announcement when I click on it. Am I doing something wrong?

[barclayrl]

I have updated the post with correct serial info
i do notice on this engine that some oil is leaking when tilted. Not sure if source

[JOE54]

common place for leaks are oil pump and engine mounted tank cap