[cfile]

OK, I've split my engine on the 79cm400 and have balancer problems. I am trying to remove the front balancer, but shaft will not come out. I did not remove the top end of the bike, and fear that one of the head bolts also holds the front balancer shaft in place, just as the rear balancer shaft is held in place by the bolt holding the oil screen. Am I correct, and if so, can I removed one head bolt and put it back without affecting the head or head gasket? If I am not correct, what could be holding the balancer?

 

[Rod Fryatt]

I have just done the same operation. There is no need to disturb the top end. Once you remove the bolt for the tensioner quadrant and the spring on the end of the front balancer shaft it should pull out.

 

[cfile]

I have just done the same operation. There is no need to disturb the top end. Once you remove the bolt for the tensioner quadrant and the spring on the end of the front balancer shaft it should pull out.

When you say, "bolt for the tensioner quadrant", are you referring to the bolt that holds the mechanism for tightening the balancer chain, ie the bolt at the end of the shaft? I have already removed all of that from the engine. If that is all that is required, I must have some damage to the case that is holding it in.

 

[Bill H]

If you have the bolt out and the spring off the shaft should slide out . Do you have the slippers loose they could be keeping the chain tight and putting pressure on the front balancer and not letting it slide out. If you havent take the slippers out remove the rear balancer and take the chain off the front balancer then if it doesnt come out start looking for the problem.

Bill

 

[drydreamer]

I assume you do not have a manual and do not know of cmsnl for the exploded views ?

 

[drydreamer]

You are aware of the dot on the end of the shaft and its purpose, the dot by the quadrant "nut". Place at 3 o clock for maximum eccentric unadjustment, but remember your engine is upside down, not that that makes a difference in this instance.

I assume the rear balance weight and shaft etc. are off as you know about the "cut out and bolt".

 

[cfile]

I have the rear balancer out and the bearing cover removed. The front balancer weight moves freely on the shaft and the shaft turns easily and slides back and forth about a millimeter. I think the slippers are removed, not 100% sure what they are but certainly the chain is just dangling, no tension, only hooked to the front balancer. I do have the shop manual and refer to it often. The only thing it says todo that I haven't done is removed the cam tensioner, but I don't see how to do that. I've looked at the exploded view in the manual, and it would seem that you'd have to have the camshaft and cam chain out of there to remove it. I also, don't see how it would affect the shaft. I do understand the dot, and the quadrant nut, the latter which is off the shaft at present, and how the tensioner for the balancer chain works. I appreciate everyone's attempt to help me, but I'm stymied. I thought maybe there was something going into that groove on the shaft that was holding it, the end of a head bolt or something. If push comes to shove, I'll attempt to replace the damaged rear balancer and shaft and just reassemble as it is. But it's a lot of work to do a half assed job.

 

[longdistancerider]

Just catching up here, been real sick for a couple of days.
There's nothing holding the shaft in the case, it's secured in position by the adjuster unit at the end. Once the spring and clip are removed from the inner end it should slide out. You've gotten that far already so now it would be a case of some sort of interference on the shaft to the case like a worn area where it sits in the case. I'd look specifically at the inner one by the spring since that where the oil flow is located and with the rear damage being likely to bad oil flow it's probable.

 

[cfile]

Thanks for all the help. Got it out with a few taps from hammer and block of wood. Looks ok, just tight on one spot near the spring. Probably a little carbon build up. Should clean up.

 

[Bill H]

Glad it it came out. I have 400a on the work bench I couldnt see any thing that would hinder the shaft from coming out. Let me know what the build up was in case I run into the same thing down the road.

Thanks.

Bill

 

[longdistancerider]

Hey Bill, cfile had a rear balancer failure that's ground into the crankshaft carrier so he's facing a complete oil passage contamination issue now.

 

[Bill H]

Ok thanks Jim.

Bill