Cannot edit my post whthout paying I guess.

Exhaust cam lobe, lifter, rocker, spring or pushrod will contribute to popping out the carb.

Not being able to correct spelling really sucks :)

The reason you do not stab the distributor at TDC is because it does not fire at TDC. It firea somewhere around 32ish degrees before TDC. That is where you should stab it if you like them straight.

It bugs me to death if my distributor is not straight.

When the cam is at 6:00 and the crank is at 12:00, the #6 is in firing position, not #1.

***Update***

Checked compression, all cylinders hitting at 150, except one at 148-150.

Good compression, no glitter or film in the oil filter...I think the cam lobes are fine?

My rotor is spinning to the right. According to the selco Mercuiser manual, a right hand rotation calls for firing order of diagram "B" below. is that correct? We had the firing order per "A" and the boat ran.

Could it be 180 out and runnig since we had firing order A?

Tomorrow it's going in the shop, plus I don't have the time or knowledge to dial in the carb before the Heatwave poker run at Havasu.

A.
3 6
4 5
8 7
1 2




B. 27563481

***Update***

Checked compression, all cylinders hitting at 150, except one at 148-150.

Good compression, no glitter or film in the oil filter...I think the cam lobes are fine?

My rotor is spinning to the right. According to the selco Mercuiser manual, a right hand rotation calls for firing order of diagram "B" below. is that correct? We had the firing order per "A" and the boat ran.

Could it be 180 out and runnig since we had firing order A?

Tomorrow it's going in the shop, plus I don't have the time or knowledge to dial in the carb before the Heatwave poker run at Havasu.

A.
3 6
4 5
8 7
1 2




B. 27563481

DAMMIT

Couldn't edit

Fig. B


5 6
7 3
2 4
1 8

Interesting. A standard rotation bbc distributor rotates clockwise. Firing order 18436572. If by going to the right you mean the distributor is rotating ccw and the firing order is reversed? Never owned a reverse rotation engine so I cannot say, but why wouldn't it still use 18436572 as the firing order? Wouldn't the plug wires just go the opposite way around on the cap? Why do you have a reverse rotation engine? Very interesting indeed!

BT

Yep, firing order should be the same (18436572) for reverse or normal rotation. Here's what I would do.

1. remove coil wire
2. remove dist cap.
3. crank engine and note which way dist. rotor spins.
4. Find #1 TDC compression (12:00/12:00, or pressure pushing your finger out of #1 hole).
5. Once #1 TDC compression is found, set static timing to somewhere around 10* BTDC (use the pointer and the damper).
6. drop in the distributor so that the rotor is pointing generall at the #1 cylinder. (that way the plug wire lengths work out ok)
7.put the #1 wire on the cap post over the rotor tip.
8.put the remaining wires in the firing order based on the rotation you saw above and the coil wire
9. If should fire up.
10. adjust timing to spec and see what happens

And just in case, and dont holler at me if you know this, but the cylinder locations are

front of engine

1 2
3 4
5 6
7 dist 8

And you need a timing light, one that you can read the full advance is prefered, or use a timing tape on the harmonic balancer.

:hammy:
go for the sledge hammer...it is easier

Yup and it's running.

That diagram in the selco manual is wrong and kinda freaked me out, but tried the reverse and it wouldn't start.

My bet at this point is timing and carb running lean. We'll find out soon enough, taking it to the boat Rx!

I'll have more info in about a week or so.

THANKS again to all those willing to help. :)

Ahhhhhhhggg

Early word is bent pushrod in #6 cyl and wasted cam lobe.

I'm wondering if the rod bent last year when my Lightning's let go and I ended up with water in the cyls? At that time the motor wouldn't start after idling, checked the oil and it was chocolate milk. Since it was only at idle, we figured no damage done and we ran the motor for one season.

Perhaps the bent rod didn't sit in the new lifter (from the current cam install) very well and wasted the lobe?

:mad: :hothead: :mad:

Now I need to figure out what type of rebuild I wanna do!

Imagine that. :rolleyes: Sorry to hear the bad news man.

Make sure coil bind or retainer smacking guide is not happening.

Thanks Info,

I'm still holding out a little hope, not sure how they diagnosed the wasted lobe. We're still hoping for a push rod/lifter or stuck valve issue.

They also told me my impeller was wasted. I had replaced it at the same time I did the cam install (1/2 hour of running time ago) and it was running fine on the lake and at my house under a hose (always under a hose NEVER dry, not even a second), was running right at 140. Not sure how that chaged in between here and the shop.

Cam lobe......:mad: Now the impeller!! I'm thinking the shop was a little light on business this week:rolleyes:

had the same issue. prior to initial start up did you prime the oil pump? sounds exactly like a flat cam lobe

lol, yes, four years ago it was a wiped cam lobe, and yes the everything was primed and lubed.

Still dunno WTF happened, but I have a new 496 stroker as the result :)

:party-smiley-004:

I know it is a pain in the a**, But if you run double valve springs, Leave the inside spring out for 30-55 min. of proper cam break in time. This reduces the pressure on the lobes a whole bunch. Then pull covers and put inner springs back in.! If you want to get real professional you can buy cam break in rocker arms that have a reduced ratio for lower pressure on the lobes and less lift for break in!

where have you been
 

I hope it didn't take 4 years to fix your cam.

I bet it didn't have a flat tappet cam either :D:D:D

Been there and done that a time or 10. :hitfan: