ronsealdeath

Sagging Member

• Dec 13, 2015

• #21

Forget book psi figures, you cant replicate the conditions land rover tested under so your readings on a diy gauge will be way off even on a healthy engine. So just go by the fact compression is more than 10% lower on one cylinder then try with oil in comp chamber to check ring wear. But have you tried a new plug and lead on that cyl? A plug firing in the environment of a combustion chamber with fuel air mix flowing over it isnt like a test in air. You can only rule spark out by replacing plug and lead in this case. It sounds to me like one is failing under running conditions.

 

D

divie

Well-Known Member

• Dec 14, 2015

• #22

I am hearing of lots of fake NGK plugs on the auto jumble circuit. Had mates chasing non or poor starting bikes. New genuine plug and all was well.

 

peter8315

Active Member

• Dec 14, 2015

• #23

just waiting for a head gasket delivery and will pop the head back on and like you say ronsealdeath, its got to be some thing along the spark line, but will look into that when got head back on, and will keep you posted as to any further developments

 

Dippypud

Never Knowingly Understood

Full Member

• Dec 14, 2015

• #24

divie said:

I am hearing of lots of fake NGK plugs on the auto jumble circuit. Had mates chasing non or poor starting bikes. New genuine plug and all was well.

Click to expand...

Years ago Champion spark plugs, then the market leader, had the same happen ... cheap nasty Spanish made plugs, more failed than worked ...

 

Dippypud

Never Knowingly Understood

Full Member

• Dec 14, 2015

• #25

ronsealdeath said:

Forget book psi figures, you cant replicate the conditions land rover tested under so your readings on a diy gauge will be way off even on a healthy engine. So just go by the fact compression is more than 10% lower on one cylinder then try with oil in comp chamber to check ring wear. But have you tried a new plug and lead on that cyl? A plug firing in the environment of a combustion chamber with fuel air mix flowing over it isnt like a test in air. You can only rule spark out by replacing plug and lead in this case. It sounds to me like one is failing under running conditions.

Click to expand...

Compression can also be lost through the valves and valve seats if they are not sealing well ... common in older engines run on unleaded petrol without lead replacement additive ...

 

peter8315

Active Member

• Dec 17, 2015

• #26

Well, put head back on today, without really doing much to it, started it up and bingo, she run's sweet as a nut, and dare i admit it, i think i had the firing order wrong, i was working on the rota arm going clockwise, and checked today and its anti clockwise, so ill put it down to a senior moment, that cost me a lot of stress, thanks all for your input

 

jamesmartin

Well-Known Member

• Dec 17, 2015

• #27

peter8315 said:

Well, put head back on today, without really doing much to it, started it up and bingo, she run's sweet as a nut, and dare i admit it, i think i had the firing order wrong, i was working on the rota arm going clockwise, and checked today and its anti clockwise, so ill put it down to a senior moment, that cost me a lot of stress, thanks all for your input

Click to expand...

weve all done it ,but main thing is it running ok now and youve fixed it yourself

 

Edlandy

Active Member

• Dec 17, 2015

• #28

Well done for sorting it out!

 

tottot

Well-Known Member

• Dec 18, 2015

• #29

Well done,just don't get a V8.

 

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honolulujoe

Well-Known Member

• Dec 18, 2015

• #30

excellent, time for a cigar

 

chris7

Well-Known Member

• Dec 18, 2015

• #31

Be interesting to know what your compression readings are now?

 

peter8315

Active Member

• Dec 21, 2015

• #32

funnily enough that was the first thing i did, and they still read around the 80psi mark, but it runs like a dream now i hav'nt took it out yet as got to put wing back on, but will report back