YASP - Series 90 failing to start

[gaffers]

are these nuts easy to find?

Do you think I need to clean things up first or just go ahead and tighten it?

[Charles uk]

John will have lots, Ebay should be ok, there must be a fastener supplier in Aldershot who carries 1/4 BSF nuts in stainless or plated mild steel in stock.

If it roared into life when you chucked fuel down the air intake I'm not convinced that this will prove to be Lilly the Pink's Medicinal Compound.

But I have been wrong before,,, on numerous occasions!

[gaffers]

Aww dont say that I was hoping this would be the reason. Dont take it poorly but I hope you're wrong

The crankcase looks pretty solid otherwise, no need to test with wd40. If there was a blow there the fresh paint (applied by previous owner) would have cracked, it's intact.

I cant test it until I get a nut and the binmen have been tomorrow

fingers crossed

[Horsley-Anarak]

Have the bin men been yet ?:D

H-A

[gaffers]

Well either the bolt into the block was corroded or I am an oaf as it broke while I was tightening.

I hope they are easy to replace?

[Charles uk]

Talk to John

Perhaps we should give the torque specifications once again, it might save some tears.

5/16" cylinder head bolts 18 ft/lbs
1/4" cylinder base nuts 9 ft/lbs
1/4" crankcase bolts 9 ft/lbs

That's probably why it broke!

[gaffers]

bugger me, I'm going to need to buy a new torque wrench to get settings that low.

I had read a good spanner tight fit........in my defence I play front row

[Horsley-Anarak]

Well, does it run?

I will give you £20.00 for it as a non runner

H-A

[gaffers]

I havent got the parts yet you cheeky bugger!

[gaffers]

I am trying to get the studs out of the block. I have tried using 2 nuts tighened together with threadlock with a liberal soaking of plusgas......and no the nuts move yet the studs are solid.

Any tips?

[charlesp]

Heat. Lots of it. On the block not on the stud.

[Horsley-Anarak]

I heat the stud and the cylinder around the stud, get the stud as hot as you dare.

A few sharp taps on the end of the stud helps, then mole grips on the stud.

Give it loads of heat in the stud area, but don't overheat the cylinder you may distort the bore.

If it shears off it can be a bit of a pain to drill out and retap.

Good luck

I can lend you a 1/4 bsf tap if you need one, or look on the bay they are quite common.

H-A

[gaffers]

Ok, I managed to get 3 of the studs out cleanly with a bit of heat, however the fourth snapped off during removal. I am guessing a drill-out and retap is in order, what size should I use?

I have imperial and metrix tap and die sets - which nicely cleaned out the threads on the other 3 holes

[Horsley-Anarak]

Dont use the metric, what you need is 1/4" BSF.

The tapping drill size for this is 5.3mm.

I normally drill them out in the mill, If it does not work you can make up a stepped stud or have a go with Helicoil.

H-A

[gaffers]

Ok, I managed to drill out the broken stud without damaging the thread too much. threads cleaned up, just need new studs and nuts