Help with Timing Light
#14
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Re: Help with Timing Light
Thanks a ton guys, I plan on doing this tomorrow. I just need to find someone to drive. I assume you do this under load at speed??? Am I wrong here, is this the way or do you do this on the hose. Once I have done it I am ok, the first time is always the charm. I did it once on another boat but never did total advance, just idle. Thanks again, you guys are so smart about this stuff, I am learning and did a search and read threads that were way above my head. I like to learn and do this stuff myself, not so much for the money savings but because it saves a 2 day sit at the mechanic and if something changes or goes wrong I can fix it because I know how it works.
#15
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Re: Help with Timing Light
If you have the Merc V ignition module I set mine at idle you have to ground the purple wire. They were both right on the money when I did a quick rev at the dock to check the advance. I can't imagine checking it at speed in the bildge on the water The total advance comes in real high with this module.
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Re: Help with Timing Light
On my stuff I prefer to set total timing instead of inital timing. Put it on the hose warm her up and I run the carb with one hand and timing lite in the other.. Rev it up till it is full advanced, then check it. I set mine at 38*. but its one of those little smallblocks Nothing like spinning it up to 6000 rpm on the trailer for grins and pissing of neighbors
If you buy and use the timing tape, Most people just stick it on.. its last a few rev ups then flys off. I put mine on and put a few coats of clear coat over it, its never coms off now.
Travis
If you buy and use the timing tape, Most people just stick it on.. its last a few rev ups then flys off. I put mine on and put a few coats of clear coat over it, its never coms off now.
Travis
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Re: Help with Timing Light
Like they said, just do it on the trailer or probably better in the water out of gear (more water flow, you can take off the prop as an added safety if your concerned it might drop into gear). Have someone at the throttle and rev it up somewhat slowly. If you have a decent advance curve (for a BB) you should only need 2500 to maybe 3000 RPM to get to full advance (just rev it till it stops advancing). If you partially loosen the distriutor hold-down first (and have good plug wires so you don't get shocked) you can hold the light in one hand and grab the top of the distributor with the other and twist it very slightly to adjust it to where you want, then shut the motor off and tighten it down. After it's tight do it again just to make sure it didn't move, if it did you had the hold-down looser than you need.
-Greg
-Greg
#18
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Re: Help with Timing Light
If you rev 3000 rpm on the hose you are going to smoke your impeller. Been there done that. Otherwise these guys are giving you two good options. Total timing is the most accurate though. Good luck and keep your hair out of the pulleys.
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Re: Help with Timing Light
ok ? have merc dist with 24-degree marked on the module how do i set the timming. i have a snapon light which will advace or retard.where should i be?
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Re: Help with Timing Light
Here's another twist to setting timing on a BBC. Check it and set it first on the #1 cylinder and then verify it by putting the inductive pickup on the #6 wire. #1 and #6 are both at TDC at the same time, just 1 revolution of the crankshaft apart in the firing order. In other words, when #1 is coming up on the compression stroke, #6 is coming up on the exhaust stroke. On the next revolution #6 is on the compression stroke and #1 is on the exhaust. In theory both cylinders should fire exactly the same according to the timing mark. The reality is that distributors do not fire exactly the same on all cylinders. I have found that they are typically off 1 or 2 degrees from each other. So, if you are setting #1 to fire at 36* TDC, #6 could be firing at 38* which would be on the edge of detonation. It could also be firing at 34* which is not a problem. That is why you should check both cylinders at total advance and set it to the one that is advanced the most. This will give you the safest timing setting to prevent damage. To be safe on your motors for sustained high rpm running I would set them at 32 to 34*. Good luck.
Last edited by MACDAD260; 07-14-2004 at 07:37 PM.
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