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

? 4 hrs

I did a 100 hr service today on my jab, I can now confirm after about 4 hrs since fitting the cobra head my plug colours are all matching, so it worked. cylinders 2 and 4 are richer, 1 and 3 are leaner, all plugs the same colour, will post pics as a comparrison. only thing I found that I was not sure about was no 2 head after taking off the valve cover the oil residue in the cover was brownish, could be condensation build up as the jab has not been ran for 3 weeks (in the UK)the ali around the valve spring on the head showed a light brown staining, so poss blow back from the valve guide, all the other heads were fine. now to do a leakdown tomorrow Regards Gary

clive, i think if you remove 1 barrel, then the knock on will affect all the barrels if you think about it, so a full torque up is reqd. i am being lazy, hoping somone has done a map to save me from working it out

hi, i was after a map, or layout so i can number the bolts in order of torque up. soon to do a topend on the jab for de cock and 1barrel to come off with suspected sticky rings

Hi Has anyone got a through bolt torque up plan, i.e which nuts in order to torque up on a 2200 engine Cheers Gary

test flight went ok, did a 2 hr sortie, i did notice my cht was up to 350 mark on warm up and taxi, but this dropped down to about 240 after a couple of mins airborne, only other thing i noticed in flight was a small vibration on my top of dash mounted gps at about 2.4k rpm, this was not there at anyother rpm. will carry out another cylinder camera inspection on my 50 hr in 6 hrs time. any one know the right torque for the prop bolts on a 2200a with a gt prop

stuffed the camera down the airbox and through the cobra neck today to check the silicon had not migrated over any of the holes around the carb inlet and tilted the carb top to the rich side, all good, just hoping the weather clears up for some test flights tomorrow. also switched to BP ultimate 98 ron fuel as supposed to clear carbon out of the cylinder according to the web site, will take a few hundered ltrs to clean mine up Lol

was a long time to fit. I took the air box off and radiused the part were the out let pipe goes inside as this was sticking through, I did a trial fit, it could of done with a little bit more of an up sweep as quite a bit out of line to the airbox. I re cut the scat hose using the middle bit of the old 1, fitted the head, quick measure up then fitted the scat to the airbox, I could then not get the cobra head on the carb, so after another 2 cuts to the scat I managed to get it on. I nipped up the clip to the cobra head carb end but the head still remains slack on the carb, there is no saw cuts in the head. I did not want to add saw cuts so I stripped it again and put a bead of loctite black rtv type silicon (hight temp fuel resistant) around the carb then reassembled the whole lot again, this time the cobra head is sitting on a bed of silicon, not sure on how important it is to get an air tight seal in this area, but is should be OK. next time its removed I will prob beef up the cobra head in this area and add some saw cuts in it the beefed up bit should stop the saw cuts migrating.

Bugger, mine is tilted the other way

so top of carb to the rich side