Enya 19

I got an Enya 19-V from Ebay - the seller (not a modeller)said it had 'good compression' - whis seemed odd as there was no plug - what seemed like 'good compression' could probably be explained by the dent in the bottom of the case the compression was at the bottom of the stroke instead of the top.

The seller gace me a partial refund which went some way toward buying a new mk-IV case from Enya UK,

I still however get a distinct 'stop' at the bottom of the stroke - the crankshaft on it's own moves smoothly and the rest of the stroke is smooth.

I've noticed that there is no gap between the top of the MKIV case and the MKV head - do I need a gasket of some sort - the compression seems a bit poor to.

Is the con rod 'bottoming out' on the case or is the crankpin bent?

Any other thoughts?

Check to see if the piston skirt is hitting the back plate or the crank web.

Trick question?

Being an Enya it doesn't have a back plate - I have noticed that the stroke is smooth until I fully tighten the frontplate to the case though.

I had this same problem with a Enya 15III. With mine, it was a bent crank shaft.

THe crank turns fine on it's own - could it stil be bent though?

Being an Enya it doesn't have a back plate - I have noticed that the stroke is smooth until I fully tighten the frontplate to the case though.
>Tony

Tony,
Check both sides of the lower end of the connecting rod. One side may have a smooth bearing surface cut in. If so, that side meets up to a comparable bearing surface on the crank pin.
If this is the case, make sure the piston baffle stays on the correct side when changing it around

Thanx George - turning the conrod round seems to have done th job!

However still got no compression - I now think that the Mkv piston/liner/rod may not be compatible with the mkiv case.

I've added a gasket between the top of the liner and head and the compression is better - still not as good as my other Enya 19's though (all mod 4003's)

It's probably worth giving it a run now.

Hi Tony,
Additional thoughts:
I have several Enya .19's but they are all Mk V's, I have no experience with a Mk IV. However, if the engine has been run extensively, things may have to re-seat because of parts becoming slightly out-of-round from running and possibly because of slight parts mismatch upon reassembly.
Piston/cylinder may have been "cleaned" by using partly or all synthetic lube. Remember this is iron/steel so perhaps using all-castor lube may restore some compression.
Also, I seem to remember that the CL version has something like 7.5-1 compression ratio vs 8.5-1 for the RC version.
In any case, let us know how it turns out.