Checking timing on 4.3L Thunderbolt IV

[gixxerjim]

I would like to check the timing on my 4.3L new to me boat. What are the idle timing value? This is a 2barrel 1992 4.3L with Thunderbolt IV. When checking the total timing, what rpm should be used and what is the total timing value? Is your value to be added to the initial value for the gauge value? Is this safe to do on muffs in the driveway or should the boat be in the water, I have heard high rpm running on muffs should be avoided.

I haven't used a timing light before but have seen it done and feel fairly confident I can do this but any advice would be appreciated.

 

[gixxerjim]

Re: Checking timing on 4.3L Thunderbolt IV

Atop my spark arrestor is the plastic cover with a sticker claiming 8^BTDC as initial timing, but no total timing value. Is this the correct value for initial? What is the total timing number?

Thanks to anyone can help out a non-mechanic!

 

[Don S]

Re: Checking timing on 4.3L Thunderbolt IV

Yes, 8? BTDC is correct. Here is the advance curve.

 

[sharkin95]

Re: Checking timing on 4.3L Thunderbolt IV

piece of cake you can do this in the driveway...take a white chalk or wite out and mark TDC on your balancer pulley which is that heavy scored line connect your timing light to black grd. and red pos. clip the the last wire to the # 1 spark plug closet to the plug as you can @650 -700 rpm's line up the marks at 8 deg BTDC by rotating the distributer right or left while pointing the light at your timing tab located on the metal timing cover. possibly someone will post a picture of the tab and marks.....oh when you set it remember to shut off the engine and tighten the dist hold down bolt first then recheck it....good luck

 

[nigels]

Re: Checking timing on 4.3L Thunderbolt IV

piece of cake you can do this in the driveway...take a white chalk or wite out and mark TDC on your balancer pulley which is that heavy scored line connect your timing light to black grd. and red pos. clip the the last wire to the # 1 spark plug closet to the plug as you can @650 -700 rpm's line up the marks at 8 deg BTDC by rotating the distributer right or left while pointing the light at your timing tab located on the metal timing cover. possibly someone will post a picture of the tab and marks.....oh when you set it remember to shut off the engine and tighten the dist hold down bolt first then recheck it....good luck

This has to be done in base timing mode, not so?

 

[Bondo]

Re: Checking timing on 4.3L Thunderbolt IV

This has to be done in base timing mode, not so?

Nope,... That's T-Bolt V,... T-Bolt IV, is point, 'n shoot...

 

[sharkin95]

Re: Checking timing on 4.3L Thunderbolt IV

Ditto ..thats where your getting confused.......

 

[IanFS]

Re: Checking timing on 4.3L Thunderbolt IV

Quote "possibly someone will post a picture of the tab and marks"

Heres a thread I posted .....some very useful stuff from the guys...

http://forums.iboats.com/showthread.php?t=565229