83 Volvo 4 cyl Bayliner Backfired when trying to start

[marinemike43]

Friend said his boat stopped running,has spark and getting fuel to carb.

When I turned it over it backfired very loud out of the exhaust.

Any ideas what this is?

PS Have not done a compression check on it yet.

Thanks Mike

 

[captmello]

Re: 83 Volvo 4 cyl Bayliner Backfired when trying to start

Might want to check the timing belt, points, plugs, etc.

When was the last tune up?

whats the history?

 

[marinemike43]

Re: 83 Volvo 4 cyl Bayliner Backfired when trying to start

He took the boat on the water and it stalled and could not get it started is all I know.
Going to check compression tommorow.

Think it could be a valve?

Mike

 

[captmello]

Re: 83 Volvo 4 cyl Bayliner Backfired when trying to start

If your getting spark and fuel then I'd check the timing belt.

You can do the compression test if you want. Post the results.

Your going to have to check everything one at a time.

Was it the first time he ever used the boat.

 

[gadget73]

Re: 83 Volvo 4 cyl Bayliner Backfired when trying to start

Crank it over with a timing light and see if it indicates #1 firing approximately where it should. If its waaay out of whack it might have jumped time, prob a bad timing belt. They're not real hard to replace, and that is not an interference engine as far as I'm aware. Its very little different than a Ford 2.3, the one used in Pintos and Mustangs.

 

[marinemike43]

Re: 83 Volvo 4 cyl Bayliner Backfired when trying to start

Does anyone know the firing order of the engine?

Mike

 

[Fun Times]

Re: 83 Volvo 4 cyl Bayliner Backfired when trying to start

Does anyone know the firing order of the engine?

Mike

I found this for you from a different post, Good luck. 1 3 4 2 is correct. cylinders are 1234 from front to back.

 

[Blackpony]

Re: 83 Volvo 4 cyl Bayliner Backfired when trying to start

Agreed - The original spec decal on the valve cover on my '85 VP AQ125A reads: 1,3,4,2.

 

[marinemike43]

Re: 83 Volvo 4 cyl Bayliner Backfired when trying to start

Checked compression and got 0 on number 1 cylinder.
All others were good
Burnt Valve?

 

[Maclin]

Re: 83 Volvo 4 cyl Bayliner Backfired when trying to start

A cylinder leak-down test will tell you.

 

[gadget73]

Re: 83 Volvo 4 cyl Bayliner Backfired when trying to start

If the timing belt jumped, it could have a valve open. Might want to pull the cover and see if the dots all line up where they should.

 

[jason32038]

Re: 83 Volvo 4 cyl Bayliner Backfired when trying to start

Check and adjust your timing. If you have the points ignition you must have the rpm EXACTwhen setting the timing because timing advances as rpms get higher. Maybe loose distributor hold down bolt? Check the easy stuff first,it's called minimal intrusion which is used on P.C.'s also. The best way to do it is to set your timing first and adjust your idle. You might have to do this a few times or more to get your timing dead on with a points ignition as adjusting the timing drastically also messes with engine rpm. Gool luck!

 

[jason32038]

Re: 83 Volvo 4 cyl Bayliner Backfired when trying to start

Also, it doesnt matter if your jumped timing or not...you should still get compression on the cylinder while doing a compression test unless the timing belt is broken and is holding one of the valves open. You can usually tell if it's a broken timing belt by doing a compression test and you find that 2 of the 4 cylinders have low or no compression and this could also be a head gasket. If you're getting compression on all of the other cylinders except for one then I would suspect something more serious like a hole in a piston from preignition,head gasket or maybe a valve adjustment. Take your time and good luck

 

[futz]

Re: 83 Volvo 4 cyl Bayliner Backfired when trying to start

What timing belt? Doesn't it have timing gears? 0 compression on number 1.
Was the test done on a warm motor? Nope wasn't running you posted.
Test is meaningless. Pull the valve cover, and look at the number one valve.
There a piece missing out of it?
The backfiring could be messed up timing, could be wa terin the gas.

Whats the oil look like, got water in the oil? pull all the spark plugs and try to crank it over, see water shooting out the plug holes?

 

[bruceb58]

Re: 83 Volvo 4 cyl Bayliner Backfired when trying to start

What timing belt? Doesn't it have timing gears?

No...it has a timing belt.

Really doubt that it skipped though. These belts rarely skip and are only off if they were installed wrong in the first place.