Engine Rebuild But Won’T Start
#1
Posted 30 July 2020 - 10:47 AM
Engine ran and started no problem prior to rebuild.
Head wasn’t rebuilt just the short motor had new shells and inspection
All back together and free and easy to turn over, I had got the dizzy 180 out but corrected that
Got spark on all 4 plugs and running lumenition ignition with Aldo yellow dizzy, same as it was before being rebuilt
Cranks over builds good oil pressure
Have had someone crank whilst I move the dizzy slowly but nothing
Has fuel as I can see it on the piston tops and plugs have been wet when removed
Can’t get the timing light to work when cranking, I thought it should work but isn’t. Wanted to see if it is massively advanced/retarded.
Will re static time it as per lumenition instructions
Carbs are as they were before rebuild, they were removed drained and placed in a box and then refit
Adjusted all tappets to 0.012 inlet and 0.015 exhaust
Only sign of life I have had from it was when I initially tried it not realising that the dizzy drive was 180 out, it gave a couple pops, I then realised the dizzy was 180:out swapped the leads to corrected it and is wasn’t for starting, so to check and correct I refit the dizzy drive correctly and rearranged the leads again.
I’m fast out of ideas, I will check the lumenition ignition today as per the troubleshooting guide but can anyone else think of something else to look at/double check?
Thanks
#2
Posted 30 July 2020 - 10:50 AM
Coil connected properly?
How fresh is the fuel?
#3
Posted 30 July 2020 - 10:55 AM
#4
Posted 30 July 2020 - 11:05 AM
Fuel isn’t new new but isn’t that old, I was thinking about siphoning it out putting it in my other car and then putting fresh 5ltrs into it as a last resort.
Battery was full, now isn’t and is back on charge as we speak.
#5
Posted 30 July 2020 - 11:28 AM
If you’re sure you’ve got a spark at roughly the right time I’d try a squirt of easy-start ..
#6
Posted 30 July 2020 - 11:38 AM
Just ideas for the pot
Fuel, Air and a spark is whats needed. Is the coil giving the readings it should?, Is it / has it got the ooomph - strong enough ?
Fuel not really any older than say 3 months ?
Have you oil in the carb dashpots ? Any blockages stopping air getting in ? No rag or tissues used to block up the inlet and outlet ports on the back of the cylinder head when it was sat away ?
Finally, I used to gap the plugs at 25 thou of an inch
As I say, just ideas for the pot
#7
Posted 30 July 2020 - 12:15 PM
#8
Posted 30 July 2020 - 12:30 PM
Carbs off and I’ll clean them as well if fresh fuel dosent solve it.
I need to check the dizzy when cranking with a meter but will need a helper so won’t be able to do that till tonight.
Yeah checked the plugs sparking after correcting the dizzy. They are sparking but I also find it odd the gun isn’t flashing when cranking. I need to run through the lumenition checks here
https://www.merlinmo...ptronicinst.pdf
And check alls good, again this is what was on it prior to rebuild so should be fine. I’m also tied to lumenition due to historic road rally regs.
Plugs are only a couple thousand miles old and genuine ngk from a motor factor so should be fine. I’ll check the gaps though.
Like I say it should at least attempt to start but isn’t. I’m thinking it’s electrical problem when the plugs are in the head as the timing gun not flashing is suspect to me!?
#9
Posted 30 July 2020 - 01:01 PM
If you have no luck - happy to come up and see if a second pair of eyes can spot the issue
#10
Posted 30 July 2020 - 01:17 PM
Fuel could be 3 months old, to eliminate it I’ll siphon it out and put 5ltr fresh into it.
Carbs off and I’ll clean them as well if fresh fuel dosent solve it.
I need to check the dizzy when cranking with a meter but will need a helper so won’t be able to do that till tonight.
Yeah checked the plugs sparking after correcting the dizzy. They are sparking but I also find it odd the gun isn’t flashing when cranking. I need to run through the lumenition checks here
https://www.merlinmo...ptronicinst.pdf
And check alls good, again this is what was on it prior to rebuild so should be fine. I’m also tied to lumenition due to historic road rally regs.
Plugs are only a couple thousand miles old and genuine ngk from a motor factor so should be fine. I’ll check the gaps though.
Like I say it should at least attempt to start but isn’t. I’m thinking it’s electrical problem when the plugs are in the head as the timing gun not flashing is suspect to me!?
If you try easy start you could save yourself an awful lot of bother messing about with carbs and fuel if it still won’t start
3 month old fuel will not be the problem.
Edited by johnv, 30 July 2020 - 01:18 PM.
#11
Posted 30 July 2020 - 01:37 PM
#12
Posted 30 July 2020 - 02:39 PM
I made the same mistake. Dizzy 180' out. I turned the dizzy through 180' to correct it. Started fine. Don't know if just swapping leads round does the job.
Initially I just swapped the leads, then corrected the dizzy drive 180, essentially they are one and the same thing but it’s better to have the dizzy drive correct in case I forget one day that it’s 180 out
#13
Posted 30 July 2020 - 02:40 PM
If you have no luck - happy to come up and see if a second pair of eyes can spot the issue
Cheers Graeme I’ll let you know if I need a lift
#14
Posted 30 July 2020 - 05:40 PM
Easy thing to check, is the engine grounded/strap in good condition?
#15
Posted 30 July 2020 - 07:21 PM
Noted that with plugs out and cranking, you have spark.
However, I'm suspect that with the plugs fitted, there's no spark or it's a weak spark. Why I suggest this is (i) wet plugs and (ii) you can't get the strobe light to flash,
Just why it would do this, I can't say for sure, but, keep in mind that while you may see a spark with plugs out, when fitted the gap is subject to much higher 'air' pressures and so it's much harder to make a spark, ie, need a higher voltage to jump across the gap.
I'm not sure if this is any help, or a wild goose chase, but these are my thoughts.
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