Topic: 466 project turned in to a 3+ year gig. now redoing the transmission.

[madmtnmotors]

If the engine is still in the frame, and the drive chain is still in place, and the wheels are still mounted, then put the trans in gear (4th or 5th will give it more leverage) then rock the bike back and forth. This will sometimes free a stuck motor.

[Jore]

It's on a stand so that's not possible, it's running kinda low on oil. Would adding more oil help?

[madmtnmotors]

Only through the spark plug hole into the cylinders, since it's likely the pistons sticking. I'm not familiar with the 400cc, but on the 750, if you remove the alternator cover then you can try the larger alternator rotor bolt to turn the engine with.

[Jore]

I filled the cylinders with atf and acetone, i'll try on the alternator side if I can nudge the engine. Thanks!

[Jore]

Updates: I took the alternator cover off, but damn screws, I ended up cannibalizing the heads on 3 of the 4 ones to get them off, good I'll replace them all. Well I tried turning the engine but with no luck, all I managed to do was unscrew the bolt, so no budging. The other good one is that I can shift the transmission but still, even with the crank pedal and the transmission in neutral and no luck, it's stuck.

What should I try now? Could heating the piston sleeves with a torch help?

[strynboen]

take the top of the engine..camchain...cam...and take the head off..too see for kororision in the cilenders..

cylender block can be rusted ..to the pinn bolts..so it not can be lifted of the engine..mine vas stuck..so have to hammer vith vooden bloks on the bottom of the silender block...it vas a hell to get it of..and not damage the finns.. heating can be used to separate the parts..fill diesel oil in borings ,,and heat to it boils..and free the pistons(if they are stock)
mine first 400 have all the same problems you have now..rust korosion stock bolts..and my frame vas heavy rusted in the front..from vater spray from the front fender area..the same problem vho ,,freze the tensioner bolts

Photo is my first 400 f..

[Jore]

That was a nice looking bike strynboen. Today I got a hold on pure lab grade acetone (benefits of working in a lab), it's way stronger than the one used for nails, so I'll try my luck with that and more atf.

On another hand, could I try cranking it with the starter motor? Or using the grease gun method?

[strynboen]

dont use elektric start...the chlutch are veak..and vill be smashed..or elektric vill get harmed...and grease vill need all valvets to be colsed to funktion..so the cam must be removed..and then it are more easy just to de montage  the hole top/head..to look insode the borings..and klean rust and heat direkt on the piston heads..vith a gas burner

[Jore]

I'll let the atf/acetone mix in the engine a few more days before trying something else, it' might need time. And thanks, I didn't know the clutches where weak. I might give the grease a try and remove just the rockers so that the valves are closed.

[strynboen]

you have to find aut the pistons posision..and find the 2 vho have to be forced dovn ,and build pressure on them..i have not tryed to pump pistons free vith grease..but vhy not..it vork vell on brake calibers..but start fill them vith acetone..then pump grease in,, to save the use of a lot of grease.the pressure can also press the acetone dovn at the pistons sides..and help it free up..have no idea if the head gasket can take 1000 psi in long time scales..it are normaly pressured for milisekunds at time..

[lajos]

Before you mess up more screws, get an impact screwdriver. I have one from HF, best $9 I've ever spent on a tool. Very easy to use and got all phillips head bolts out without any damage on a complete bike and engine tear down (I had a stuck cylinder stud but thats a different issue ;).

http://m.harborfreight.com/impact-screwdriver-set-with-case-37530.html

I've used the atf/ace mix with great success on rusted bolts, but atf and acetone separate if left alone. So if you filled your cylinders with the mix, acetone probably moved to the top and evaporated by now.

For my stuck pistons I used mystery oil and atf, started moving the next day. I turned the crank from the ignition side with the nut at the end the crank, but my engine is a 550 so not sure if you have the same nut.

[calj737]

Dont use the nut under the ignition side, use the stator side nut.

[Jore]

I do have an impact driver, but even with it there's some screws that won't move, since I'm changing them for allen screws I don't really mind if I have ti mangle a few to get them out.

I'f tried turning the crank from both sides with no luck, so for the moment I'm playing the waiting game with atf/acetone mix. Plan B will be with the grease gun.

[lajos]

Dont use the nut under the ignition side, use the stator side nut.

Cal's advice of course makes perfect sense, there's a beefy bolt on the stator side and small pins and delicate stuff on the ignition side. I think I got lucky with my motor starting to turn fairly easy after an about 50-50 mix of atf/marvel mystery oil soak.

[Jore]

I'm clamming mild success, I've been squirting Liquid wrench done the spark plug holes for the past few days and also I've squirted some rust converter, and gave it some heat with torch, well I tried cranking it and still it won't crank over,but now it moves a little bit more and I can hear a light clunk from around the cylinders every time I try to crank it.

So the second part of my plan is going to use the grease gun method to free the pistons, also I read that I could take a piece of wood and start banging around the cylinders and that should also help.

[Jore]

IT'S FREE!!!!!!!!!!!!!

Today I came home early and headed down to my neighborhood machine shop with a spark plug and a 1/4 inch grease zerk in hand, about 40 minutes later and 5 bucks less and I came out with this:



Well, armed with my new gizmo I came home, loaded the grease gun, and look for the pistons that where near BDC, I started with the center piston form the right side if you're facing the engine, started pumping and pumping some more, and then out of the exhaust port it started to leak some of the atf/acetone/liquid wrench mix, but a few more pumps on the gun and it stopped, after that I heard a clunk and grease started to leak out from the threads of the gun, stopped took out the grease adapter and look down the spark plug hole, it seemed full, so the clunk I heard must have been the piston going all the way down.

I decided to try the right outermost  cylinder since I figured it should be on or near TDC, I started pumping the gun again, the lever starts to get kinda heavy and now soft again, give it some more pumps and now grease starts coming out of the previous cylinder, success finally!

Since the gun was still loaded I gave it a go on the outermost cylinder on the left, start pumping grease in to it and I notice the atf/acetone mix gushing out of the center piston, and it had some power to it, you could see it jump about 3 cm with every pump from the gun. I would have done the last cylinder but I ran out of grease.

Now I know it's free, but my concern is why I can't crank it using the lever even if the transmission is in neutral, or at least I think it is, since you can turn freely the drive sprocket.

[calj737]

a coupe of things: seated on bike from left to right, cylinder 1, 2, 3, 4

if the cylinders are full of grease, remove all spark plugs. use the bolt under the stator cover only, and manually rotate the crank to help expel the grease you just added. You'll need to remove the head to fully clean the cylinders of all the grease too.

[Jore]

Thanks Calj I wasn't sure of the order of the pistons.

So now that the pistons are free, I'll manually turn the crank to get the grease out, but what should I do regarding the kick starter? with the clutch pulled in, the kick start lever will move freely, but the transmission's in neutral it won't move, no even with my whole weight on it.

[madmtnmotors]

Thanks Calj I wasn't sure of the order of the pistons.

So now that the pistons are free, I'll manually turn the crank to get the grease out, but what should I do regarding the kick starter? with the clutch pulled in, the kick start lever will move freely, but the transmission's in neutral it won't move, no even with my whole weight on it.

Where you say "but with the transmission in neutral it won't move" do you mean with the trans in neutral and the clutch lever released? If that is the case, then it sounds like something in the clutch assembly is binding and you likely were not dealing with stuck pistons. Have you had the clutch apart? I have no experience with the "little brothers", but I have had an identical condition with a CB750. Clutch in=kicker works, clutch out=kicker no worky. There were clutch components that were interfering with each other effectively locking the drivetrain in place.

[Jore]

Where you say "but with the transmission in neutral it won't move" do you mean with the trans in neutral and the clutch lever released? If that is the case, then it sounds like something in the clutch assembly is binding and you likely were not dealing with stuck pistons. Have you had the clutch apart? I have no experience with the "little brothers", but I have had an identical condition with a CB750. Clutch in=kicker works, clutch out=kicker no worky. There were clutch components that were interfering with each other effectively locking the drivetrain in place.

Yes, that exactly, clutch in = kicker works, clutch out = no worky. The last time the bike ran I was having clutch issues, it had some really bad clutch slippage, actually one time the bike had been warming up for a few minutes and it tried to take it out of a garage with a really pronounced incline and the bike just stopped midway will climbing through engine still running but with tremendous clutch slip. The other thing is, the pistons started to move with little to no effort while using the grease gun.

[Jore]

I'm officially blaming the clutch. Reading through the forum I found several similar stories, most of them go something like the bike sat for X amount of time and then kicker/starter is stuck.

This morning a got some grease for the gun and gave it a go on the cylinder I missed last night, it moved without problem, so I tried the biggest ratchet in my tool box and gave it a go, it turned effortlessly, the grease squirted out and landed a few meters away, and then with each turn you could hear the pistons sucking and popping the grease that was still around, with my hand about 10 cm away from each spark plug hole I could feel air rushing out of the pistons during the upward travel.

I pulled in the clutch and the kick lever turns easily, it's stuck if the clutch's out. I also left the transmission in gear and turned the crank from the bolt on the stator side, you could see the drive gear turn with each turn of the crank. I'm happy with my results, and I planned on changing the clutch either way, so I'll get to that soon enough.

[calj737]

Yeah, not uncommon for the clutch disk to seize up after sitting for so long.

[Jore]

it's been stationary for almost 2 years, so I guess it was bound to happen.

How can I address that problem?

[calj737]

Easiest way is to put bike and gear, and rock it. But, to get it into a higher gear (3,4,5) you'll need to be rotating the rear tire while shifting to aide in synching the transmission.

[Jore]

The engine is on a stand and out of the frame for the moment, so rocking it can't be done just yet. Currently I can shift it to first, neutral and second, and can't get it to other gears, since there ins't a lot of oil inside it, would filling it up and letting it sit a couple of days and then manually turning the pistons work? I'm thinking that maybe getting oil in pump again and having circulate might help with the clutch bind.