Eliminateing counter balance weights

[flht1550]

Can a person eliminate the counter balance weights in a B motor. I have a friend that whats to build a stroker this winter and was wondering if it was possible. Is there and reason to discourage this.

[ThumperDeuce]

I am thinking about leaving the balancers out of my "B" engine this winter also.  I have not decided yet.  The downside is increased vibration and all of the potential headaches that go along with that.  The upside is decreased rotational mass.  Without the balancers you should be able to build a 7k rpm engine.  I recently emailed Hoban brothers about this.  They replied that they change the balance factor used if you leave out the balancers.  Also they would have no problem doing this on a bar hopper, but that the balancers are nice for touring.  I am in the process of replacing all the bulbs with LED's and going to a HID headlight to get rid of the filiments.

[Horizonmech]

 Yes the counter balance system can be eliminated, he will have to live with a bit more vibration.....If I remember correctly there is an oil passage that needs to be blocked off....the good side is he will be able to raise the rev limiter higher ( the 6200 limit on the B motor is mainly to protect the balance system bearings)......

[sonicskip]

There's a link to an article about lightening the counterbalance shafts in the tech tips section of HTT.
http://www.hotbikeweb.com/tech/0807_hbkp_twin_cam_b_motor_modifications/index.html


That would seem to me to be a reasonable comprimise.

Skip

[flht1550]

horizonmerch, Can you tell me what oil passage needs to be plugs. Or is there a tech tip on this that you know of.

[HD/Wrench]

The softail has a oil passage from the cam plate side through the case to feed the hyd tensioners. You can drill and tap it right at the cam plate side. Install a allen plug with red loctite and reinstall the o- ring done deal. It is the feed with the screen in it. You can also upgrade your system to the lighter version  of counter balancers from the 07 and up engines.

I have removed them and for a street engine the dowside is not worth it.
Now R&R has done this and claims with there crank much smoother than other methods. Reggi Jr has a 117 without balancers in his bike and claims very very smooth.

I have not done one and until I could ride a bike with that set up, would stick to saying leave them in unless you are drag racing the bike.  My own 124 was done without balancers ( hoban dark horse S&S crank)  and yes you can rev the bike past 6200, but in the upper rpms is had a heavy buzz. Go ride a 124 stroker evo in a softail if you are ok with that then go for it.

Correctly set up the B motor will be fine with the counter balancers left in the bike.

[11.7to1]

I have an 01 softail, untouched bottom end. I have had the rev limiter set at 6500 for the last 6 plus years. I have considered removing my balancers as well, but could not rationalize it for another 500 rpms. Better results from cam selection.

[HD/Wrench]

11.7  I know of many B motors that are spooled past the 6200 limit.  The engines that we have seen that had spun the timing sprocket where either done from panic stop on rear brake no clutch or missed shift.  Had one customer get confused ( his words not mine) and down shifted the bike from 4th gear to 1st and let the clutch out. Engine started to shake bad right then and there. With some common sense a 6500 rpm will work.  Even with that the large selection of cams are done making power by 6000 RPM anyways so adding more rpm is for what reason?? If not the cam the heads are done making power. Speaking in terms of street engines for the most part.

[ThumperDeuce]

My motivation for doing it is not to build up a 7k engine as much as getting an engine with quicker throttle response through out the range.  I also want to lose the compensator and go with an open primary.

I am not a wrench so I have not seen any engines which have been run for awhile and then disassembled.  Doesn't the polymer tensioner shoe wear (crumble) putting pieces in the oil like the cam chain does?    I never liked the way that setup looked.  I've tacked my balancer gear,  I understand the criticism about the need of having this be a weak point but I don't want it to slip out of timing.  Otto had an engine come in a couple of months ago in which the balancer chain broke and balled up in the case, not a pretty sight.Is there a stronger aftermarket chain that can be used in this application?  What are the differences between the old and new balancer setup?  How much lighter are the new balancers?  I know that Jim's 120 "B" engine was suppose to have improved the bearings ( I think they developed a tapered bearing, I don't remember anymore ) but they would not sell just that  part of their engine to use as a reto-fit.

One thing to keep in mind is that it is not an irreversible decision.  They can be put back in.  Too bad you have to split the cases to do it.

[11.7to1]

Not to be mean, but being confused and going from 4th to 1st, now that's funny right there. I think the stars and planets were aligned when my bottom end was assembled, I have beaten this thing like no tomorrow. A little over a year ago I actually broke all 5 rear pulley bolts. The dealership couldn't believe it. The broken bolts were all tight in the wheel hub.

But you are right, anything can be done when done right.

[hotroadking]

I've had my 00 B stroked for several years.

Its been though a lot but non of it I can see are the fault of the balancer system.

I still run the balancers for the street and would not pull them, it was discussed because it has been
rebuilt by SNS twice.  First time the balancer covers were not properly bolted down, caused the bolts to break.

Second time, the bolts did not get sufficient clamping load, they would TQ to spec but not load properly, both cases it caused rattles from the balancers.

SNS tossed in the new flywheels they just came out with, and properly installed the balancer covers so far it's been running good.  ON the street it is nice and smooth.

Can't see why anyone other than a drag racer would want to go back to the Old Evo blurry mirrors and eyeball ride..

[11.7to1]

Thumper, let me say this. A given mass is happy to accelerate. It is the sudden deceleration of a given mass in motion when things go boom.

[HD/Wrench]

My motivation for doing it is not to build up a 7k engine as much as getting an engine with quicker throttle response through out the range.  I also want to lose the compensator and go with an open primary.

I am not a wrench so I have not seen any engines which have been run for awhile and then disassembled.  Doesn't the polymer tensioner shoe wear (crumble) putting pieces in the oil like the cam chain does? no not really they seem to hold ok seen engines with close to 70 k on them and the strip where worn but not to the point of creating a issue I never liked the way that setup looked.  I've tacked my balancer gear,  I understand the criticism about the need of having this be a weak point but I don't want it to slip out of timing.  Otto had an engine come in a couple of months ago in which the balancer chain broke and balled up in the case, not a pretty sight.Is there a stronger aftermarket chain that can be used in this application?  What are the differences between the old and new balancer setup?  How much lighter are the new balancers?the difference is the way the bearings and counter balancers mount, as to weight the older version weighed in at about 6. 25 lbs give or take the newer ones are much lighter I dont recall what I weighed them at though maybe 4 lbs ?? sorry it was over a year ago when I did it and did not note the weight sorry  I know that Jim's 120 "B" engine was suppose to have improved the bearings ( I think they developed a tapered bearing, I don't remember anymore ) but they would not sell just that  part of their engine to use as a reto-fit.

One thing to keep in mind is that it is not an irreversible decision.  They can be put back in.  Too bad you have to split the cases to do it.

[ThumperDeuce]

Can the new style balancers and bearings be retro-fit into a 2004 case?

[HD/Wrench]

Yes they can.

[ThumperDeuce]

Are the new bearings compatible with the old balancers?  The idea being to turn down the old balancers on a lathe to lighten and balance ( saving some money ) and yet getting the benefit of the improved bearings?  Or do you have to do both together?