scottw wrote:
smokescreens wrote:
so i went out to the garage to tinker on the bike even though im still waiting on parts to show. played around with the valves some just to make darn sure they are set right and i also did the leakdown test again making darn sure all the valves were closed and the result is originally i thaught my exhaust valve were bad but as it turns out i was just a tad past TDC and the valves opened just a hint but after i double checked it all it im not leaking air out the intake or exhaust im losing 40% out both cylinders (not the 60% like on my first test) and i turns out i cant hear of feel air in the pipes or carb but im losing it into my crank case did a compression test on the front and got a dry test of 90psi but my battery started to turn slow for the rear so i gotta wait for it to charge back up to test that and to do the wet test. so what should i look at rings and head gasket?
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Dont do anything to the motor yet!

Do the following and i bet your test results will be better/more compression.

* You need to hold throttle wide open when doing comp test because throttle plate thats behind the carb slide is almost fully closed at idle sig blocking/reducing incomming air to fully fill the cyl for proper comp when doing comp test.

* You also need to remove the air cleaner so you can hold up throttle slide and or prop it up/open because its also blocking air from enetering carb/motor for proper comp results.

If you dont do the above 2 items the motor still shows compression but is some cases (not all) the avail air to be sucked in with throttle plate closed and throttle slide in lowers position blocks significant air from entering the cyls reducing overall comp reading for each cyl.

* Also,you said your battery was so weak it only had enough power to get a partial comp test on 1 cyl,well thats no good too which can also reduce comp reading on 1 cyl you tested so far.

You must start with a battery thats in decent cond thats fully charged so motor spins over at a decent speed at least thru 3-4 full strokes of comp at same approx cranking speed on each cyl for a proper comp test. If your bike battery isnt that good you can use your cars battery with jumper cables to ensure you have consistat battery power to ensure motor spins over properly/even when comp testing both cyls

* Its better to do comp test with motor at normal op temp but its not a must,its more important if you have suspected issues with ring seal & or valve sealing in heads with a tired motor that when it heats up & things expand those issues are more likley to show thier ugly head.

* And of course as you already know you need to deactivate the de-comp solenoid on motor to ensure its not releasing compression for proper test results .

When you do all of the above then you have done a proper comp test to get the full potetial /max comp reading for each cyl .

Scott

thanks scott.

i did hold the slide wide open and the battery was pretty good on the front jug but with a full charge i will do both with a warm motor and full charge on the battery and disconect the decompession soliniod. on a side note should i do a dry and wet test or just the dry with a warm engine??

If the dry test comes out ok there is no need for a wet test. The wet test just lets you know if a compression loss is rings or valves. If you have low (out of spec) compression on a dry test you would do a wet test. If the compression come into spec on the wet test it would indicate worn rings. If it didn't come into spec on the wet test it would indicate a valve issue.

ok so now i did the compression test the corect way.

1. hot engine
2. diconect/disable the decompression soliniod
3. hold carb at WOT
4. wet and dry test
5. fully charged battery

off the service manual.

the minimium compression should be 142 Lbs
the standard compression should be 171 Lbs
the maximium compression should be 199 Lbs

and here are my findings.

i was even as far as compression goes but i barely made it past the minimium compression at 150 Lbs ( wet test made a 2 lbs difference to pressure bringing me to 152 lbs) so i would assume that tells me that my rings are good but even though my compression falls within specs it barely makes it past the minimium presure. when i did the leakdown test i was losing 40% into the crank case, i could feel the air coming out of my crank breather and if i blocked it off for a few seconds when i removed my thumb i could hear a rush of somewhat pressurized air coming out of it. im no mechanic by any means but im pretty sure its a bad head gasket. but i wouldn't mind opinions, (honest opinions)

Proper compression tests are done with a fully warmed engine and NO impediments to the air intake charge.

Usually no more than 6 revolutions are typically necessary, but cranking at strongest starter speed is also necessary, requiring a fully charged battery.

All things considered, if you're getting equal compression on both cylinders within specs, you're probably truly good, even if the numbers you are looking at seem to be on the low side.

If you've no reason for rings, gaskets or valves to be bad... you're likely running full compression.

I am still leaning towards SVS the 05 was really bad about that especially if you have been jetted too rich.

but if a valve was stuck open i should lose the air into the exhaust right? im tight as a drum on intake and exhaust valves. im losing all my air from the leakdown test into the crankcase and its coming out of my breather hose. in fact when i unbolt the rockerbox cover and remove it you can really hear the air rushing out of the heads somewhere. if i put the covers back on it gets quiet again and when i unbolt the exhaust there is no change in sound at all, still quiet until i remove the rockerbox cover.

Smokes
I think you are chasing a ghost and gettin yourself all worked up over nothing. I don't think you have a problem. The head gaskets are separate from each other so in order for one to be bad it would be allot lower than the other. Move on my friend and don't look back.

smokescreens wrote:
ok so now i did the compression test the corect way.

1. hot engine
2. diconect/disable the decompression soliniod
3. hold carb at WOT
4. wet and dry test
5. fully charged battery

off the service manual.

the minimium compression should be 142 Lbs
the standard compression should be 171 Lbs
the maximium compression should be 199 Lbs

and here are my findings.

i was even as far as compression goes but i barely made it past the minimium compression at 150 Lbs ( wet test made a 2 lbs difference to pressure bringing me to 152 lbs) so i would assume that tells me that my rings are good but even though my compression falls within specs it barely makes it past the minimium presure. when i did the leakdown test i was losing 40% into the crank case, i could feel the air coming out of my crank breather and if i blocked it off for a few seconds when i removed my thumb i could hear a rush of somewhat pressurized air coming out of it. im no mechanic by any means but im pretty sure its a bad head gasket. but i wouldn't mind opinions, (honest opinions)

Don't forget to account for altitude on your pressure readings. I was checking compression on my 04 and it was way low (only has 3500 miles). I live in Denver and didn't realize how much difference the altitude makes. The max, min and standard readings in the manual are for sea level. When I factored in altitude it was perfectly normal.

Don't forget where your crankcase vent is. If you are leaking past the valve stems then you are leaking into the crankcase as well or you are leaking past the rings.

Curt, the valve stems and seals are isolated from the cylinders when the valves are closed.