Very Strange Piston Question

[bladebj]

Hi everyone

i have a question

while i was replacing my clucth plates i noticed that i can rotate my engine (crank) with my finger very easily




it is like there is no compression

all plug are on it

can be my pistons distorted or its normal

it should not be easy like that to me

please inform me

thanks to all

[The Buddha]

It will turn, but how much ... you can take it through a whole cycle
Cool.
Buddha.

[bladebj]

It will turn, but how much ... you can take it through a whole cycle
Cool.
Buddha.

yea full cycle and very easily

i cannot understand how it turn but it turns full cycle very easily

but there is no white blue smoke and any significiant power loss

i have stock parts and my carb has a little sync issue

i can reach 60 km in 8-9 rpm on first gear

85 kmh in 8-9 rpm second gear

and 120 in 8-9 rpm in third gear

but after 120kmh i cannt have enough power and on 5th gear my bike doesnt go to 8 rpm stuck on 7 rpm but i thought it is because of my carb and fuel issue

[ineedanap]

I bet you're turning the transmission, not the engine.  There's no way an engine with that little compression would run.  What part are you turning?  

Your tool in the picture would be turning the hub and pressure plate (transmission).  

The engine is attached to the basket, not the hub.   

[bladebj]

i am not master but my friend who rebuilt a husaberg told me it s very strange

hmm we did  not rotate the clucth we rotated the other shaft which the signal generator rotating on it is it not directly attached the crank?

yeah you are right there is no way i think we did a theory mistake

I bet you're turning the transmission, not the engine.  There's no way an engine with that little compression would run.  What part are you turning?  

Your tool in the picture would be turning the hub and pressure plate (transmission).  The basket (attached to engine) is the part that surrounds it with the "fingers" and has the gear attached to the back of it .  

[The Buddha]

The piece you have your wrench in that pic is the center of the transmission shafts and Ineedanap is right, in neutral it will spin free.
Cool.
Buddha.

[the mole]

If you rotated the signal generator, that is the end of the crankshaft, and you should feel a distinct resistance to rotation as each piston comes to the top on the compresssion stroke (once each full revolution). If not, you have a problem.     
In your photo it looks like there is oil seeping from the head gasket area. If you do a compression test you can find out what you need to know.

[bladebj]

The piece you have your wrench in that pic is the center of the transmission shafts and Ineedanap is right, in neutral it will spin free.
Cool.
Buddha.

this photo dont show which part i rotated, i rotated shaft on the right (sginal generator's shaft)

[bladebj]

If you rotated the signal generator, that is the end of the crankshaft, and you should feel a distinct resistance to rotation as each piston comes to the top on the compresssion stroke (once each full revolution). If not, you have a problem.     
In your photo it looks like there is oil seeping from the head gasket area. If you do a compression test you can find out what you need to know.

yes i thought in the same way but if my pistons have a huge problem like that how can i get power from this bike

ok i change my question you said that a resistance to rotation while rotating the signal shaft yes we feel a little resistance but again we can rotate it with our finges (the signal gen. shaft)

is it normal?

dont we need apply some force while rotating

is it easy to rotate with our fingers

[the mole]

To rotate mine I use a spanner on the nut on the end of the crank, it is easy to turn until it gets to the compression stroke, then I need to put quite a lot of force on the spanner. If you can turn yours a full turn with your fingers you have very low compression, which would explain the low power you seem to be getting.
Like I said, you need to get a compression test done. It shouldn't cost much.

[gsJack]

I've managed to ride 370k miles on 6 bikes over the past 25 years without ever using a compression guage on any of them putting 80-100k miles on individual bikes which were well worn when I was done with them.  I've done all my own maintenance and repair work on my bikes.

A simple finger in the hole compression test will tell you in 5 minutes if you have enough compression to run well and if the compression is equal enough in both cylinders.  Take 5 and check it.  A loud pop about equal sounding for both cylinders tells you enough to get going.

[bladebj]

yea i will apply the test soon

To rotate mine I use a spanner on the nut on the end of the crank, it is easy to turn until it gets to the compression stroke, then I need to put quite a lot of force on the spanner. If you can turn yours a full turn with your fingers you have very low compression, which would explain the low power you seem to be getting.
Like I said, you need to get a compression test done. It shouldn't cost much.

[bladebj]

thanks man i will try it

I've managed to ride 370k miles on 6 bikes over the past 25 years without ever using a compression guage on any of them putting 80-100k miles on individual bikes which were well worn when I was done with them.  I've done all my own maintenance and repair work on my bikes.

A simple finger in the hole compression test will tell you in 5 minutes if you have enough compression to run well and if the compression is equal enough in both cylinders.  Take 5 and check it.  A loud pop about equal sounding for both cylinders tells you enough to get going.