Made a leak test and compression test today, after about 20 min warmup, at my 1958 FLH with following results:
Leak Test: Front Cyl 16-18% / Rear Cyl 15-17%
Compression Test (dry): Front Cyl 86 PSI / Rear Cyl 115 PSI
Copression Test (oil on piston): Front Cyl 101 PSI / Rear Cyl 138 PSI
During the leaktest with the timing hole plug removed, all the air noise came out of the crank case. No noise at the intake and no noise at the exhaust at all.
Here is what the plugs look like: (left Front, right Rear Cyl)
I make about 600 Mi a year. The bike starts good and runs smoth at 30 and 50-60 mi/h. Any advise? Is this critical? Immediate action required?
Thanks to all comments
Leak Test, Compression Test
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Please do not start new topics here, but here: New Panhead and Flathead topics
Please do not start new topics here, but here: New Panhead and Flathead topics
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Re: Leak Test, Compression Test
Is it a newly rebuilt engine?
I recommend a intake leak check and repair.
Next I recommend putting more miles on the bike.
That rear plug look new.
Jim
I recommend a intake leak check and repair.
Next I recommend putting more miles on the bike.
That rear plug look new.
Jim
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Re: Leak Test, Compression Test
do like what James says,but make sure the throttle is wide open when compression testing,are you running solids,or hydraulic tappets? noise at timing hole is normal .
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Re: Leak Test, Compression Test
Intake leak---The plug looks like it came out of the box.Remember to check the cover screws over the intake real good with soapy water/With a hole big enuff to run that lean-you probably can swipe your fimger accross the bottom of the manifolds clamps & it will be wet.Remember to do manifold first / then do another test with the carb. on.Those numbers rule out a head gasket.Let us know what you find.---Respectfully----RICHIE
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Re: Leak Test, Compression Test
Richie, can you elaborate on testing with the carb on? I am a believer in applying positive air pressure to the intake manifold (10 to 12 psi), but I'm not up on testing with the carb installed. By "wet" do you mean wet with gas?58flh wrote:Intake leak---The plug looks like it came out of the box.Remember to check the cover screws over the intake real good with soapy water/With a hole big enuff to run that lean-you probably can swipe your fimger accross the bottom of the manifolds clamps & it will be wet.Remember to do manifold first / then do another test with the carb. on.Those numbers rule out a head gasket.Let us know what you find.---Respectfully----RICHIE
Thanks,
Mark
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Re: Leak Test, Compression Test
MARK---Sorry I didn't get back sooner////But yes If a clamp is leaking -You can run your finger under both & they will be wet with gas.---Its funny I got so use to getting guys bikes ready for the season & Anyone that didn't fire by the 3rd kick/It was always the Intake leaking somewhere.I always check timing & go over a bike before I try to fire it.If you don't get a Cough or kickback from to much adv. by the 3rd kick HOT!-after priming,To me somethings wrong!These bikes start very easy!--Just find compression-stroke & relax your leg-It has to start!-If everything is in order.Also a good suggestion that somebody said before----After you fix her PUT SOME MILEAGE ON Her!.The worst thing is letting them sit for long periods of time!-Remember when you shut down & put her up in your garage /As she cools WATER is forming!--& that's not good for anything.Its good to run her even if olny weekends,But def. run her.After you check your manifold for leaks /its good to put a shop/vac hose so it blows out & Affix to carb.--Spray soapy water on shaft ends To check for wear/& hold the throttle open.Usually I find a Manifold o-ring or two!.The carbs. usually are good /But if a LINKERT-Always check.Remember those are nice carbs. & have TONS OF USE on them.Those You find bubbles now & then.-----Respectfully----Richie
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Re: Leak Test, Compression Test
Back with some findings:
to Jim: the engine was rebuilt back in 1989 and has about 2600mi since, the Rear Head was replaced (used one), new set of pistons +0.04 (inkl rings), new valves and guides +0.008. The plugs on the picture are new and have 150mi.
to JrJohnson: I made the compression test again, choke and throttle full open: Front Cyl 95 psi, Rear Cyl as before 115 psi. I run hydraulic tappets.
to Richie: I will do the manifold leak test, but first has to make this pressure plate with the nipple to put on the manifold. Let you know what I will find out
to Jim: the engine was rebuilt back in 1989 and has about 2600mi since, the Rear Head was replaced (used one), new set of pistons +0.04 (inkl rings), new valves and guides +0.008. The plugs on the picture are new and have 150mi.
to JrJohnson: I made the compression test again, choke and throttle full open: Front Cyl 95 psi, Rear Cyl as before 115 psi. I run hydraulic tappets.
to Richie: I will do the manifold leak test, but first has to make this pressure plate with the nipple to put on the manifold. Let you know what I will find out
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Re: Leak Test, Compression Test
ok, I think I found the troublemaker. I made the manifold leaktest and there was only one spot with bubbles.
I made some pictures: Rear Cyl Head
Picture taken from the r.h. side Do I have a chance to fix this leak?
Thanks, Martin
I made some pictures: Rear Cyl Head
Picture taken from the r.h. side Do I have a chance to fix this leak?
Thanks, Martin
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Re: Leak Test, Compression Test
The intake nipple on my front head looked like this, and I was able to get it to seal. I retested a couple of months ago, and it still wasn't leaking.