First time starting problems

[Shorty]

OK, so, today was supposed to end with me sharing the good news that I'd got my engine running for the first time...

It isn't :roll: 

I started with confirming I had oil pressure without the coil connected. I do.

I initially diagnosed that I had put the fuel pipes to/from the pump round the wrong way. Once correct I checked for fuel in both after cranking the engine. All good.

Next I suspected the electronic ignition / older OG Bosch 009 dizzy, so I swapped that out for the dizzy supplied with the engine.. A new but repro unit running points. This action didn't change anything, so will probably revert once engine is running.

So, having confirmed oil pressure, fuel pump working and eliminated a potentially tired dizzy, I then moved on to the spark.

I grabbed an innocent passing neighbour and got the to hold the timing gun while I cranked it over. My theory at least is that should the timing gun flash, then the spark plugs must be sparking... We got a flash.

I then removed the air filters and poured a thimble of petrol into each.. this helped a little...

However, it seemed that the valves were open on the ignition stroke - instead of exhaust (perhaps_ as I suddenly had lots of popping coming from the exhaust...

hmmmn..

So, swapped my HT cables over 1 for 3, 4 for 2, effectively turning my dizzy through 180 degrees.

I tried it another couple of times, but by now my battery had had enough for today, and frankly, so had I!!

Battery on charge now.

Anyone got any ideas what to do next?

I can't help but suspect the carbs are starving the engine of petrol... I initially thought it could be the coil, but as we have confirmed a spark is present, then I have (rightly?) eliminated that..

 

[Rippers]

Basics would be leads in the right order, checking spark at each cable with the strobe, where the points gapped in the dizzy?
Then double check the timing, is the pulley marked correctly ie is DTC really DTC? I think you can check this with a pencil if you take out the plug in cylinder two and at the lowest point ie furthest point the pencil goes into the engine should be DTC, the mark out 11mm to the right of this for 7.5degree BTDC and set the timing on idle.
If your not even getting it to start try rotating the dizzy until it does and work from there

 

[StuF]

Was your carb totally clear of fuel after the rebuild?
Might just need to get the floats filled up which can take longer than you would think?

Rebuilt my bike engine and it took an age for that tiny carb (125cc bike) to get enough fuel into it before the bike would start.

Keep persisting and I bet it will fire!

Good luck

 

[Shorty]

Was your carb totally clear of fuel after the rebuild?
Might just need to get the floats filled up which can take longer than you would think?

Rebuilt my bike engine and it took an age for that tiny carb (125cc bike) to get enough fuel into it before the bike would start.

Keep persisting and I bet it will fire!

Good luck

I was thinking this myself.. the fuel pump is a puny little thing and the floats are huge... battery on charge now overnight... might have another play tomorrow with this as the first port of call perhaps...

 

[KevH]

However, it seemed that the valves were open on the ignition stroke - instead of exhaust (perhaps_ as I suddenly had lots of popping coming from the exhaust...

I don't suppose the valve clearances have been set with TDC set for No.3 cylinder rather than No.1 by any chance?

 

[ozziedog]

I been chatting about something similar with a mate of mine, after looseing my fuel pump last Friday roughly four months after fitting a new pump and rod. I was so impressed :evil: :evil: :evil: . If you take a fuel pipe off of your carb or off where it hits the splitter if you have twins. Pop it into a clear bottle then crank the engine so you can see how or if your pump is working. What we were chatting about was,,, how do you describe a good full bodied squirt squirt squirt from your pump, this is because as I cranked,, the bruvver in law watched and we was getting weird and conflicting reporting as he did actually see it squirt a few times,, but thought that was good enough, when I watched,, it pulsed then it didn`t then it did. :shock: :? :shock: So as a very very rough rule of thumb, if you pop the pipe into a one litre or a one and a half litre bottle, the squirts should bounce off the back of the level bottle when you is cranking, not just dribble with an an inch or two inch splurt. A good fuel pump should fill your float chambers (and not your floats) within seconds when cranking over Five seconds max I guess as the floats fill up most of the chambers anyhow.

Ozziedog,,,,,,,,,,,,,, Hope this helps :mrgreen:

 

[Shorty]

However, it seemed that the valves were open on the ignition stroke - instead of exhaust (perhaps_ as I suddenly had lots of popping coming from the exhaust...

I don't suppose the valve clearances have been set with TDC set for No.3 cylinder rather than No.1 by any chance?

You got me thinking now.....

 

[Shorty]

I been chatting about something similar with a mate of mine, after looseing my fuel pump last Friday roughly four months after fitting a new pump and rod. I was so impressed :evil: :evil: :evil: . If you take a fuel pipe off of your carb or off where it hits the splitter if you have twins. Pop it into a clear bottle then crank the engine so you can see how or if your pump is working. What we were chatting about was,,, how do you describe a good full bodied squirt squirt squirt from your pump, this is because as I cranked,, the bruvver in law watched and we was getting weird and conflicting reporting as he did actually see it squirt a few times,, but thought that was good enough, when I watched,, it pulsed then it didn`t then it did. :shock: :? :shock: So as a very very rough rule of thumb, if you pop the pipe into a one litre or a one and a half litre bottle, the squirts should bounce off the back of the level bottle when you is cranking, not just dribble with an an inch or two inch splurt. A good fuel pump should fill your float chambers (and not your floats) within seconds when cranking over Five seconds max I guess as the floats fill up most of the chambers anyhow.

Ozziedog,,,,,,,,,,,,,, Hope this helps :mrgreen:

Cheers O-dog! The pump is near the top of my list of culprits.. It's like a game of cluedo this!!

 

[Shorty]

Sorted now after several hours spent checking, setting, not working, trying something else over and over again, it turned out to be a knackered repro dizzy that turned/did not turn at it's own will... Grrrr!