Distributer gear.

[capthook]

My distributer gear broke yesterday. I got a big back fire then nothing. Do I need to pull the head and look for tuliped valves? What should I do to check to see why this happened? The gear is shearded completely on one side. I am at a lose here what would cause such a thing? Thanks in advance.

 

[Don S]

Re: Distributer gear.

A compression test would tell you about the valves. WHY the gear broke, well you may never know exactly. Possibly one tooth broke and sat between the cam and distributor and bang, it breaks.
I would also check the cam gear. It is probably tore up as well.

 

[JMRuth72]

Re: Distributer gear.

Hello, Not sure what caused the backfire. I do know there is a list of things that can cause a backfire. Have you made sure that ALL of the pieces of the gear are there. If not you may need to slowly go through the engine and look for pieces. The last thing that you want at this point is to miss a piece and have it tear the engine up. I wouldn't think that you should have to pull the heads, I have had several older cars that have backfired and didn't do any damage. Could be that the gear was just worn and weak. Just some things to think about.

 

[bomar76]

Re: Distributer gear.

A likley cause is it's 33 years old.....things do wear out.
A big concern of mine would be where are all the little shards of steel hiding now?
If it were mine I'd tear the engine down (especially considering it's over 3 decades old) and freshen it up.

 

[capthook]

Re: Distributer gear.

Thanks for the replies. I would like to tear the engine down and rebuild but the last time the compression was checked it wasn’t bad at all. I will do another now that this has happened. A little four banger would not be too hard to rebuild. What would be the best method of checking the cam gear? As for finding all the pieces, I think that tearing it down would be the best bet. Man now I am going to miss the best part of the year on the river. Thanks guys. If anyone else has anymore suggestions please chime in. If I can get a picture I would show the damage. Also someone suggested that the weights in the distributor my have been a culprit.

 

[Don S]

Re: Distributer gear.

What would be the best method of checking the cam gear?

Remove distributor.
Look in hole. Use flashlight if it's too dark.
Turn engine by hand and look at the gear all around.

 

[capthook]

Re: Distributer gear.

Thanks Don. I will let you know tha outcome. By the way does Iboats sell the gear? I could not find it on here.

 

[blake in spokane]

Re: Distributer gear.

years ago the same happen to me, your oil pump is worn

 

[Don S]

Re: Distributer gear.

years ago the same happen to me, your oil pump is worn

While it is a possibility, you make it sound like that IS the ONLY reason it can happen, and it's not the only reason a distributor gear will break.

 

[Bondo]

Re: Distributer gear.

Ayuh,.........

Lots a things can Break a Distributer Gear,.........
But,.........
With the amounts of Water that tend to get pumped by the Oil Pump,........

It's a Darn Good place to start Checking,..........
Like turning it over by Hand.......

'ell,.......... You've already got the Distributer Out........

 

[capthook]

Re: Distributer gear.

Well I guess the first thing to do is check for debris and if the cam gear is crap then check the cmpression on all cylinders, then check the oil pump. What is the best way to check the oil pump. Turn it by hand and look down the hole? Also where is the best place to get a gear. Mercruiser, here at iboats? I have been working a lot of hours so I am hoping to get to it this weekend. Thanks everyone.

 

[Silvertip]

Re: Distributer gear.

33 year old distributors can have very worn upper and lower bushings. It could be either or both of the bushings was worn oblong enough that the gear mesh simply was no longer tolerated and she jammed and broke. The backfire was likely caused by the breakage as the engine lost its timing, not the other way around. What is surprising is that the roll-pin didn't break before the gear broke.

 

[capthook]

Re: Distributer gear.

I thought the same thing about the roll pin. As far as the oil pump will I be able to tell if it is working or not. I watch my gauges constently and it was reading 40 all day long. Has anyone replaced a pump without pulling the engine? I am not sure if I have room or not to get to it. I guess I just need to stop assuming all possibilites and just work on it and take it one step at a time.

 

[Bondo]

Re: Distributer gear.

Ayuh,.........

With the Gear Off the Distributer, you should be able to reinsert it,+ manually Turn the Oil Pump.........
It should turn Freely,+ Smoothly.......

Btw,........
Oil Pumps are Not changed with the motor In the boat..........

 

[bomar76]

Re: Distributer gear.

Well I guess the first thing to do is check for debris \.

There is no "Checking for debris"....
There IS debris now scattered thoughout the engine in every nook, cranny, crevis, and most likely bearings.