Leak down / compression tests

[xfuctx]

Need help with leakdown procedure. 99XX

The Reason i'm doing this is, bike boiled over at beach 95F 2 yrz ago (heat knock, green sweet stuff that pets like to drink was on the ground etc..) and to kick me while i was f'ing down, i watched aircooled vtwins go by w/no probs? figure that out? cowling? pump not efficient at low rpm? i dunno.

Anywho... Honda stealer said it was common for birds to do this on hot days.???. then they listened to the bike and disagreed that any knock was there at all :evil: (well fuck me in the ass and call me susan) my hands were tied at that point i guess, and that (lack of knock) still seems to be in my imagination 2 yrs later . In addition to the knock prob, i can't set the idle to recomended 1100 rpm as it knocks heavily and backlash loudly when it leaves cold idle (clutch pulled in quiets this a little tho)

After that minor discrepency at the stealer, i did a compression test and ... for cylinders 1,2,3,4... got #200,215,190,205 PSI respectively. during this test i think i forgot to hold the throttle open if it matters? Vacume reading Pulse rapidly at idle as well, heard this is normal w aggressive cam/engines? idunno.

I have a compressor, sparkplug hole adapter, and tons of other tools,

do i need anything else? cirtain type of guage for monitoring the pressure on the chambers? techniques for procedure?

My goal is to get my hands dirty and have this bird running like new agn.

Any help appreciated thnx

XfuctX

[Northman]

I see no need to do a compression test or a leakdown test.

Make sure your coolant is clean, and the strength is right. The cold knocking you are experiencing is the damping springs in the clutch hub.

Perfectly normal until the bike warms up.

[XX4me]

I'm with our brother from the great white north on this one. I doubt the compression has anything at all to do with what your describing.

The over heating could have been due to a poor mixture, sticky thermostat or even air in the system.

The knocking and backlash you described sounds alot like poor firing of the cylinders causing an uneven power stroke. Pulling in the clutch just takes that niose out of the equation.

My 2000 did that somewhat, especially when she wanted plugs.

[xfuctx]

I was hoping i would hear responses like these as i always figure worst case senarios with auto repairs, forgot it was a bird for a minute there.

Plugs are ordered and hopefully clear up that bag o' marbles and if not, i may suspect my knock sensor... here i go again lol. but XX4ME you got me focused on timing now cuz she does have a shuffle in the rythem at idle and a heavy unburnt fuel oder. flushed coolant and added with prestone 50/50 for second time since the boil just to be shure.

Northman, you metioned the clutch damper springs, are those the six springs that load the clutch plates? I think ill do em any way since i have drageraced beforefore and beat those plates to a pulp with some novice crappy launches. the ones that go whhhheeeeeeeeeuuuuuuu. lol If you done that before than you prob know what i mean.

While i wait for parts i shall remember that the bird is bulletproof, and shit, she still gets up first and second without the need for a herckyjerck first. that's just raw power baby. :twisted:

[demon]

Plugs are ordered and hopefully clear up that bag o' marbles

Hmmmmmm, how many miles on her?

Bag o marbles usually spells CCT.

The 6 springs are your regular clutch springs. The hub is a damped unit, not solid like aftermarket billett replacements (for dragracing)

[TechnoGecko]

I'd just do yourself and replace the following things to make your bird happy.

#1 - CCT, it'll quiet the rattle and give you some piece of mind

#2 - Thermostat - cheap and again, good piece of mind incase yours is on the fritz

#3 - Change coolant, might as well while you're replacing the thermo

.. the rattle you hear without the clutch pulled in is the clutch rattle, its normal on the birds. After I got mine I thought something was wrong with it as well, but I quickly learned it was normal.

Also, you might want to give Joe (rockmeupto125) a PM about any remaining X11 CCTs. I can't remember if he got rid of all the ones he ordered or not.

[xfuctx]

I did the cct about 3 thous mi ago (not x11 tho) and this is deeper, to clarify more like a bag of lead marbles or like bad or low octane gas. i probed it :? , and it's coming from the bottom end/ cylinder area definitely. sounds like it.s at each cylinder combustion time.

I see where i strayed about the damber springs now i need to get back to studying ghoty more.

[xfuctx]

didnt know tb plates effect compression i guess that i just assumed the intake valve would isolate the preessure in the chamber from the tb. im thinking this is like an valve overlap thing?

anyway, i will do it agn ( the right way) with em closed, when i get my new plugs.

just a thought, if it,s not compression and this knock proves to be a timing mixture issue, any suggestions on sensors that may have been effected by boilover to cause a rich condition?

cool temp sensor, knock sense, or melted wax unit?

[rideonXX]

If you are doing a check to discover the compression----the throttle needs to be OPEN. As mentioned in a post above, check done with throttle closed brings other issues into the mix---clouding the diagnostic process. At least relative to actual compression. Happy trails kel

[xfuctx]

Brain fart i meant with them open

[OZXX1100]

I once had pre-ignition problems that produced symptoms that sound similar to yours.

That was caused by seriously neglecting the oil change interval and resulted in heavily carboned up combustion chambers.

My fix was as follows:

Changed oil and filter (put a budget oil in first).

Put a bottle of Motul engine cleaner in oil and ran for ten minutes.

Changed oil and filter again (used the good stuff this time).

Put fuel system/ injector cleaner into full tank.

Ran that tank of petrol empty over the next week.

Changed oil and filter again.

Changed plugs.

Put fuel system cleaner in again.

Waited for about another tank of petrol or two to run through bike (takes me about a week to use a tank), using fuel cleaner in each tank. By about the end of the first tank, noise was almost gone.

Voila

All my noises disappeared never to return.

I now run fuel cleaner every fourth tank fill.

My problem was so bad that I had carbon flakes randomly jamming under valve seats. Compression tests would show one time a certain cylinder down and then another at the next test. A leak down test was done and valve seals proved to be fine.

Once I got the shit out, all was good again.

Motul was the only "motorcycle" engine cleaner I could find so with respect to the wet clutch, I went with it.

When I saw the oil come out the first AND the SECOND time :cry:

Will never neglect my baby that way again.