Crusader 350/270 engine issue

A

Andy

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Joined
Jun 30, 2013
RO Number
33316
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4
Hi all

1986 Wellcraft St Tropez
Twin Crusader 350/270 with Quadrajet Carbs
Mallroy Unilite Breakless Electronic Ignition

Please could you let me know what the timings are for both port and starboard engines?

Also just recently my starboard engine has started to misfire on the odd bank of cylinders. I have replaced all fuel filters, plugs, leads and Flame Arrestors

During testing I am using a new remote fuel tank with fresh 89 octane fuel.

Both engine appear to be running a little rich based on the inspection of the spark plugs, however I am guessing this is normal only running on low revs and short journeys.

Thank you in advance :)
 
Timing should be done with a adjustable timing light. Based on what grade of gas you use, set the timing light to 32 degrees advance for high test, 30 for mid-grade. Run the engine at 3000 RPM and the timing mark should be adjusted and set at 0 degrees.
 
Many thanks guys. The distributor and its components all appear to be in a new unworn condition, however I did notice the springs have started to rust.

I will check and adjust the timing this week and report back. Prior to this issue the engines seem to run clean and smooth with no oil loss or burn
 
Does it misfire at idle or just at higher rpm's?

Crusader spec'd timing at 10*BTDC at 750RPM in N ('88 owner's manual but I'm pretty sure it was the same for '86).
Back when I had those carbed engines I talked to the head Crusader factory tech and asked him about the high-engine-speed(3000) method of timing and he said they only use the 10* BTDC(after retightening) at 750 RPM procedure and recommended sticking with that with the recommended 89 octane gas(manual spec). The manual also has a big Caution note: If 89 octane is not available and you have to use lower octane ,down to 86 , retard the timing 4* to prevent detonation.
If you are by any chance the ""one person"" who is still using breaker points, the Dwell angle spec is 28-31*( after retightening.)

If it is more than 1 cylinder missing , it seems a bit odd that it would just be the left bank as viewed from the flywheel end unless the firing order was mixed up ( 2 swapped plug leads at plugs or cap?) or there is a something like a head gasket leak.)
If you have any question as to which cylinder(s) may be involved, if it's just electrical it should be revealed by attaching the timing light's inductive pickup to each plug wire in succession and watching for particularly erratic strobing.

A manifold vacuum test could also be revealing if you don't find any obvious electrical cause. .
 
Cmariner has it for the more advanced DIY tuner guy (or gal) with the basic ignition systems. Sandy's way, or the OEM way is for the general public. Once you get into the electronic ignition (especially the MPI) systems with knock sensors, it's best to go by the book. Controlling 'Knock' is done by retarding the timing but can also be done by richening the Fuel/Air mixture...both of which can be accomplished thru the ECM.
 
Guys thank you for your input, I will be back to the boat this weekend and will come back with my findings. Is it possible to upload a video to the site as a picture speaks a thousand words!
 
I think you could upload to uTube then provide a link to that.
 
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