No compression, Lifan 125

[headsmess]

wow, my first post in...um... a long time!

ok, no compression.

all this talk about clutches... could be chasing wild geese around the paddock?

first...pull the spark plug out. kick it over. does it go "woof woof" out the hole? is there spark? that will give you an idea if its simply the clutch slipping, or, as mentioned earlier...if its a valve issue. or you could take the caps off the valves and see if they are actually moving as expected. you gotta make sure the engine is actually turning over before blaming the clutch!

cus theres a whole lot of issues you may have, you gotta eliminate each and every one.

it starts (apparently?). but makes a horrible noise. so, theres a possibility that the cam chain tensioner is bust, and it may have jumped a tooth or two on the cams.

you said you looked at the rings...have you synched/timed the cams properly when you put it all back together? or retensioned the chain tensioner properly? and YES, the tensioner REQUIRES OIL. its sort of hydraulic...

it could be the kickback arrestor on the camshaft holding the exhaust valve open. i usually tear the things off, kickback doesnt bother me as i know how to start my bike(s) properly

the knocking noise could be the main bearings, they can sound freaking awful...did i see a mention of running it with no oil? same deal goes with rod bearings. the knocking could be one of the bearings collapsed, the piston smacking around like a...like a... meh. something to check.

it could be that kickback arrestor, has let the exhaust valve hit the piston, bent it, and nothing except replacing it will get it to seal again... remove the head. clean the chamber. fill it with some kero. leave it overnight. any signs of kero in the ports... think about replacing the valves. they may just need a re-grind.

just looking at the rings is no good... the bore might be glazed, which could be fixed with a simple honing, and getting a new set of rings... even if they do look a-ok, theyre cheap, and easy to replace.

and, if it is the clutch... maybe its stripped its splines out... it would just spin on the crankshaft then, which isnt going to do very much... except make nasty noises, mostly.

and, while talking clutches... plates? any missing teeth?

sorry if some of the things ive mentioned arent the issue...i just ramble

 

[ericbarile]

Okay thanks for the reply, okay first thing the clutch all I'm saying is there must be something wrong with the clutch because even when in gear holding in the clutch won't allow you to roll the bike so that's first thing. 2nd thing valves yes they are working right opening and closing and the cam wheel tensioner isn't bust it's all nice and tight and yes oil is used and yes timing is right.
I don't think it's the kickback but there is no backpressure coming from the exhaust and there is no missing teeth on clutch plates.

 

[my67xr]

When you push the bike along in 3rd or 4th gear can you feel resistance, eg; the engine turning over ?
If there is then it has compression.

To adjust the clutch, first put the bike up on a milk crate of stand to get at least the back wheel off the ground.
Next unhook and remove the clutch cable from the arm on the gearbox.
Now take the round cover off ( held on by 2x philip's head screw's) the clutch cover, the one that say's Lifan.
You will see a 10mm head nut with a screw in the middle, the flat plate behind it should have about .5mm movement in and out to the actuator rod.
If there is a lot of movement there you need to adjust it.
Loosen the nut and turn the screw in until it allow's the plate a touch of movement.
Then do up the locknut firm while holding the screw.
Once tight check there is a bit of movement at the plate there still

Now do you have some channel lock plier's or a shifting spanner ?
If put them on the arm that the cable connect's to and move the plier's/spanner down to engage the clutch
You will see the cam on the clutch actuator shaft turn and push the plate in toward's the engine
Do this a couple of time's to make sure the clutch is disengaging, check if the back wheel can be turned whilst in gear
If that work's then you can refit your clutch cable to the front of the cover.
Back off the cable adjuster at the lever on the handlebar's so it's screwed right back in.
Now adjust the inline cable adjuster that is about 100mm up the cable from the engine, so that there is about 2mm - 3mm movement before you feel resistance when pulling in the clutch lever
Check if the clutch is working now and let us know if the clutch now work's as it should
There will still be a slight resistance when you push the bike in 1st gear with the clutch lever pulled in.

 

[ericbarile]

Thank you okay first thing yes there is resistance when in 3rd and 4th gear, so I've done as you have said put the bike on a stand unhooked the clutch cable from the arm adjusted the actuator rod even though it was good but the clutch is still not disengaging while holding the clutch in 1st and 2nd gear .

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[my67xr]

Did you try the channel lock's moving the clutch arm ?
The clutch cable might be stretched, try tightening it up a bit more at the lever

 

[headsmess]

my head hurts...

this started as no compression, like the thread title says.

so, that could mean simply that the clutch was slipping, as the lifan kickstart drives through the clutch.

but now it seems the clutch simply isnt disengaging.

but that shouldnt feel like no compression. it should start in neutral no probs.

how you bump starting it in second if the clutch isnt disengaging? when you push it in second does the wheel lock (plenty of compression, no clutch slipping) or just spin? (no compression or slipping clutch...)

*gives up and goes out for takeaway*

cant help if the issue or the description of the issue keeps changing on every post...

 

[ericbarile]

I will try that but the clutch cable is brand new, and I thought having no resistance in the kick start has to do with the compresseion, okay maybe it might be the clutch slipping. Well my bad if I was wrong about the problem being compression still kind of knew to all of this stuff, I've been reading and it's all just kind of common sense and a lot of simmilarities to a car but as I said I'm still kind of new to this stuff. Well now I am unable to bump start it but yes usually in 2nd gear, and yeah when in 1st gear holding the clutch in doesn't disengage the clutch it's hard to roll then in 2nd there is less compression and easier to roll and so on so I guess it must be clutch slipping but I don't think that's the only problem.

 

[ericbarile]

Sorry for the confusion

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