ET: Engine (Twin) Leak down test
- Thread starter Bill Cannon
- Start date
Thanks for all the help guys.
Can any one help with the thread of the cylinder studs where the two halves screw together?
Cheers Bill
Can any one help with the thread of the cylinder studs where the two halves screw together?
Cheers Bill
10 mm x 1 mm pitch fine.
Thanks Greg, but shit, metric I'll have to scrap the bike now!
Cheers Bill
Cheers Bill
Good thing you don't have an RTV then........ That's where all the changes started.......All the case through studs were 8 mm fine pitch........ Yuck.
As it has only done 1000 miles I doubt it has had time to settle down yet. Looking at the plugs , I reckon to go down on the idle jet by one size. get the heads back on, do another leak test before fitting the pushrods ,just to prove the rings. Your storeman most likely has the required nuts on the shelf. Be lucky, Roy.
Thanks Roy.
Gardner carbs so no idle jets! But I can screw the needles down a bit after starting with the richer setting.
Unfortunately BMW rarely use fine thread, I'll have to nick some off my XL185!
Cheers Bill
I’m not one to use the chemicals sold at the local auto parts store and think majority are snake oil. One of the things I do use is combustion chamber cleaner. When Honda introduced the 4 valve engines in 79 there were some situations where bikes would come in (usually after lots of in town riding) and the valve clearance was excessive. Long story short.....It eventually became evident that installing thicker shims to take up the clearance and not dealing with the carbon would lead to erratic idle or burnt exhaust valves once the bike was driven on the highway for an extended period of time. In a case where the leak down test suggests things are leaking past the valves and wind isn’t blowing out the crankcase breather, then I wouldn’t take an engine down until I had run combustion chamber cleaner through it and repeated the leak down test.
Not sure who makes it, but it was given the factory’s blessing.
Not sure who makes it, but it was given the factory’s blessing.
I've just put a new 40 mm Gardner flat slide on my racer.......not too sure about race carbs on a street bike. I just rebuilt a Shadow with TT Amal's on it..........great carb's and very well made, but not easy to tune unless you have a good supply of slides, jets and so on.......My thoughts are that they tend to run very rich which is ideal for a racer, but difficult on a road bike. The Gardner's have very little in the way of adjustments, so you might want to re think of the practicality of using these........I could be wrong, but I'm just going off my own experiences. I've yet to find out for myself how to set up the Gardner.......once the bike comes back from having it's exhaust done, its time to fire it up for the first time.
Sorry for radio silence but the thread got locked for editing. Graham has kindly re-opened it.
I tried the petrol in the ports and then in the chamber, no sign of leakage at all.
Rings and bore are both good.
I'm now thinking the tester has led me up a blind alley!
I'll re-grind the valves anyway having gone this far.
I've removed the front head as well to de-coke it.
The only other possible cause of the symptoms I can think of is the valve timing has moved but this seems unlikely as my cams are welded to their shafts. Having written this it just occurred to me that a damaged rocker could cause this as well. Unlikely but I'll check.
After 30 years of ownership I still yearn for that utopian vision of having an Egli that I can take for a long ride and have a good likelihood if getting home without a problem arising!
Cheers Bill
I tried the petrol in the ports and then in the chamber, no sign of leakage at all.
Rings and bore are both good.
I'm now thinking the tester has led me up a blind alley!
I'll re-grind the valves anyway having gone this far.
I've removed the front head as well to de-coke it.
The only other possible cause of the symptoms I can think of is the valve timing has moved but this seems unlikely as my cams are welded to their shafts. Having written this it just occurred to me that a damaged rocker could cause this as well. Unlikely but I'll check.
After 30 years of ownership I still yearn for that utopian vision of having an Egli that I can take for a long ride and have a good likelihood if getting home without a problem arising!
Cheers Bill