G-OMER

Ok, I assisted my friend with his low leak down on pot 1, his turned out to be rings lined up, so re align and new valves seen the pressure come to 75/80 A couple of weeks later I did mine, rings not in line but second ring stuck in piston and heavy scoring 90 deg from the stuck ring. Replacement barrel fitted, new rings and replacement head, test run and 80/80 pressure seen. Test flight today seen pot 1 temps climb out 350, cruise 288 at 90 knots 2600 rpm. Pot 4 showed 300 climb out and 240 at 2600 90 knots I varied the temps by backing off etc

I checked the old ex valve from the spare heads i bought and the collets completely close around the valve, now this motor has not had the valves changed, its serial no is towards number 2000, waiting for the exact number, i got 2 complete heads, 1 barrel and 1 complete piston with rings and pin. My original plan was to drop 2 and put these on then drop the other 2 , im now going to drop all 4 at once, so will prob re sell these parts

Well spotted, i just slung them on for the photo to check for a gap

Attached is pics of the new valves, the collets close completely around the valve and the valve rotates within the collets, these came from skycraft UK there is a step just below the collet were it looks like the last bit has been machined down as smaller dia than the valve shaft

I bought the valves from skycraft, i am replacing the barrel with a fully serviced unit from Roger, i also bought 2 fully serviced heads as well, so at the end of the job I will have all these parts available for the future or if any one else wants them

I am going to fit a new set of rings to my number 1 cylinder jab 2200, due to a 65/80 leak down, suspected stuck rings while i am doing a de coke on all 4. I also intend to fit new exhaust valves at the same time to all 4 motor done 500 hrs. What are the thoughts about changing the oil to a run in oil because of the new rings? And what grade to use? Im in the UK and currently run 15/50 aeroshell, would it matter for these, cannot see at the moment the benefit, does it help with the bedding in? How long does it take to bed in? Cheers Gary

New Facebook page for UK based Jabiru aircraft photos and discussions http://www.facebook.com/home.php?sk=group_156777114357786&id=215135188521978&notif_t=group_activity#!/JabiruAircraftUsersUk

yes. yahoo jabiru forum, another bloke with a 80/65 on number 1. thats 5 popped up in the same amount of weeks. trending.... Gary

thats the next move, had a top end overall course in december with Roger Lewis

no 1 has been like that for the last 3 leak downs regardless of what pot you piss in first

no 1 has been

me neither, is there a trend forming?

leak downs were 1 80/65 2 80/72 3 80/75 4 80/72 could only get 20 min flight after the service the next day from a 3 week lay up

bondloc 620. this is exactly the same spec as loctite 620 but 1/4 of the price in the uk

yep, correct