Silver Century not starting

[Glenn19750]

Hi, newbie to SOS and plenty of good advice read already. I got my first 40+ late last year, and have successfully rebuilt another from a sold-as-seized condition so I’d like to think I know my way round them a bit.
My issue is with a Silver Century WS1582A0. I got it locally and in an unseized condition. Little rust, but nothing terminal. The thing is, I just cannot get it going, I have so far done-

Set points to .020
Set new D16 plug to .025
Bright spark on drill test
Woodruff key present. Baseplate ht outlet at 4 o’clock.
4-5 mm play up/down on flywheel. No slack side to side or front to back
Checked main jet 45 = 10:1
Compression ~50 psi
Oiled crankcase inside with neat 2-stroke oil.
Leaky float chamber fixed, tickles correctly and fuel seen on main jet. Fuel system flushed several times.
Head off- piston slope correct.
Water channels clear.

It feels as if no fuel is getting into the combustion chamber. Has anyone experienced a blocked transfer port? Plug looks dry after each attempt to barrel start. Am I missing anything obvious?

[RickUK]

I wouldn't suspect the transfer port - check that both carb jets are clear, either by taking the carb. off to check (look through), or with the carb in situ, take the float bowl and the throttle cap off and shine a torch from the underside to view through the jets. Also check the float chamber banjo bolt for muck, and the filter which should be present in the bolt recess. I realise that you have seen fuel present on the main jet.

Compression is low but still OK to start, and may come up once the engine has run.

[Charles uk]

Plug gap should be 20 thou but shouldn't make much difference & try a squirt or 2 of easy start, that will show if the carb is working.

[Glenn19750]

Thanks both. Will try those tips over the weekend. Won't be giving up on it.

[Nudge]

Do you have a spark? Sometimes the HT lead may look ok but a lot of the time that is the issue. If you don't get a cough with the engine start / wd40 / CRC or fuel in the plug hole then I put 10c on the HT lead.

[Glenn19750]

Looks like a v strong spark when held against cylinder head and flywheel turned with a drill. I do have a spare lead so will give this a try at weekend, just in case it’s not sparking at pull cord speeds. Thanks, will post back with results.

[Nudge]

I hope you have oil in the cylinder and crank case when you use the drill. Not something I would do!

[Glenn19750]

Ok, spent most of the morning tinkering with the suggestions made. No luck, so I bit the bullet and started on a power head strip down. The bolts were all suspiciously loose, on removing the block I found the crankcase to block gasket did not have the hole cut out for the transfer port. Hence why no fuel/oil charge was getting to combustion chamber! This was not rebuilt by me!! Well now it's all apart, I plan to hone, replace piston (damage to port side of skirt!) and new rings. Then will rebuild with new gaskets and a high compression head I have from a 59' Century I'm breaking.
Thanks for all the advice chaps.

[Glenn19750]

At long last. Rebuilt @nd fired up on 4th pull. Few more little tweaks before dinghy test. Thanks for the advice everyone.

[Journeyman]

Glad you got it going, not a problem you would expect to find!

[Charles uk]

Glen it would be fascinating to see how much difference your upgrade makes to the compression figures, do you have a gauge?

Run it, stop it, remove plug & fit gauge, 3 or 4 pulls, take reading, & exactly the same after upgrade.

[Glenn19750]

I do have a compression gauge so will check over the weekend and post back. Curious myself, have to fit a new water pump rotor as this one had perished. Have the parts now so will see how I get on over the weekend.

[Glenn19750]

Much later than stated so sorry for that. Finally got new rotor in and pumping good flow of water. Did the compression test and returned a solid 70psi. Well up on my base reading with the low compression head. I would say this conversion is well worth the effort.
Thanks again for all the help. Next project - 40 plus with bing and steel tank!

[Charles uk]

What was the compression difference between before & after?

[Glenn19750]

50 before, 70 after. Can't judge real world difference on the water as it wasn't running when I got it. Should make a difference to cold starting. Ran it for 10 mins today to clear fuel out of tank. Might get a sea test with fresh fuel tomorrow.