aq131 timing issue / no start

[axisg]

Some background information. Boat ran great last fall but I was getting small amounts of oil in the antifreeze. Fast forward to last week and I pulled the head, had it machined and #4 exhaust port repaired.

Today I replaced the head and attached the intake, exhaust, carb and fuel pump to test fire the motor before I screw around with the heat exchanger.
Figured I had lined up the 3 timing marks and tried to start ( no start ). Re-checked the marks and they are all set. Slipped the timing cover on and the timing mark would be appx 0 deg when the bottom sprocket is lined up on the marks.
I have fuel and spark.

Then I popped the distributor cap and it was pointing at cyl #4 ( 180 deg out ) ???

I then started over again and pulled the timing belt and lined up the distributor with cyl #1 and it matched the timing mark
Lined up the top timing mark with the bottom timing mark using a length of rope ( it appears both the cam mark and the crank mark should literally line up with each other with the line passing thru the cam bolt and crank bolt )

I tried a re-start and got a backfire ( figured I am getting closer ). I tried advancing and retarding the distributor but it still wont start.

2x batteries fully charged
I have a good strong blue spark
Fuel is getting in the carb and I tried with starting fluid as well

I spent about an hour getting it all bolted back together and over 3 hours trying to figure out why it wont start.

Any suggestions would be helpful. It must be in the timing somewhere

thx

 

[MikDee]

Re: aq131 timing issue / no start

It is a 4-cycle engine, and #1, & #4, piston are at TDC at the same time, But, only one is on the compression stroke, the other is on exhaust. You have to determine that by putting your finger over #1 spark plug hole to test for compression when cranking. It takes 2 revolutions to make a complete cycle. If it's not on #1, (it would be on #4) then crank it over One Turn to TDC again, and it will be on #1. Then, either take out the Dizzy, & put it on #1, or just move your wires clockwise on the cap to match.

 

[axisg]

Re: aq131 timing issue / no start

I think I have this figured out.

Watched some vids and did some further research and it looks like I set up my timing off the crank on the wrong keyway. There is one recessed and one raised keyway on the crank snout. I have been timing it off the raised keyway and now think perhaps I should be using the recessed one.

 

[axisg]

Re: aq131 timing issue / no start

Hmm, getting closer I think. It sounds better cranking over and will run ( barely ) off the starter, quickstart and with the throttle wide open. Then when I let off the key it stumbles, backfires, and stalls. Advancing and retarding the distributor has little effect. I have ordered up a new timing belt hoping its marking will help get it all in-line.

I find it very aggravating that I have a notch in the cam sprocket but no reference point to line it up with. The intermediate shaft has a dot and a bracket with a notch. The Crank has both a positive and a negative keyway to match up with the mark on the block ( I think negative is the correct relation ). Of all the pictures I could online I find more than half have the cam sprocket lined up at 12:00 and the others show a relation closer to 11:00 which is a difference of 4 teeth. Surely I will have this running sometime tonight.

 

[Walt T]

Re: aq131 timing issue / no start

 

[MikDee]

Re: aq131 timing issue / no start

View attachment 229696

I don't know if this regards to setting Cyl #1 on TDC, or Cyl #4, on TDC? You'd hafta try it both ways, unless it's stated somewhere near pertaining to this diagram? If it fires up, you're set. If not, you have to give your Dizzy 1/2 a turn, or move your plug wires on the cap 180 degrees! Just remember, each crank revolution it is either #1, or #4, that's ready to fire, your camshaft which turns at 1/2 speed of the crank will determine that!

 

[axisg]

Re: aq131 timing issue / no start

LOL, thank you for the post above but I have 2x diagrams for setting the timing. One for the 131a shows the top gear at appx 11 O'clock. The Diagram above is for the B230 which is set at 12 o'clock ( its a difference of 4 gears on the cam ). The issues I had were that there is no reference on the valve cover or the block to align the cam gear to.

I purchased a new timing belt with the marks on the belt. With the new belt installed and all the reference points lined up the engine fired 2nd try tonight. Timing checked in at 15 deg which I backed off to 10 deg @ 850 rpm. I will leave it there for now until I get the cooling system hooked back up and up to temp

http://www.volvoclub.org.uk/faq/ImagesProcedures/TimingMarks1.gif

 

[Walt T]

Re: aq131 timing issue / no start

It is always #1 TDC. That diagram is for a 131. Glad it fired up for you! Those are a pain to set up.