I'm considering a "gearing" change via changing out the front pulley on my 2014 Breakout to as small a pulley as I can get (because I have the high rpm Stage 4 Race kit now, which revs a lot higher than stock to make decent power).

I need to make sure that the drop in pulley size is not going to have me run out of belt adjustment range.

I don't have access to a pulley not on the bike and behind the primary cover, so:

What is the WORKING diameter (i.e. the diameter that the belt is actually riding on, not the "flange" diameter) of the 32 tooth pulley?

If I know that, I can calculate what half of the circumference is, and then calculate what half the circumference of the smaller pulley would be, take the difference, and then divide by 2, to get how far further back the rear wheel would have to move to restore proper belt tension.

Jim G

 

The general rule of thumb is dropping one tooth on the pulley will not require a belt change but dropping two teeth on the pulley you will require a one tooth shorter belt. You do realize that dropping teeth on the transmission pulley will INCREASE your rpm's.

 

Yes, raising the rpm is the intent.

I have also been told that changing the clutch sprocket in the primary to a larger sprocket achives the same thing but costs less, does not require a belt change, and does not upset the speedometer, but does possible make the "6th gear light" inoperative, since that light is DEactivated when engine rpm versus road speed mathematically exceeds what the ECM is expecting based on factory gearing and factory ECM programming.

It is puzzling to me that a 2-tooth chnage in countershaft pulley should require a belt change. I say this because the stock 32Tcountershaft pulley is approximately maybe 5" in diameter (very rough guesstimate since I don't have access to one). Changing to a 30T would make the pulley 30/32 x 5" = 4.69", a change of 0.31 in diameter. Therefore the change in CIRCUMFERENCE of the pulley is 3.14159 x 0.31" = a drop of 0.97". The belt actually runs over less than 1/2 the pulley circumference (since the pulley on the rear wheel is just over twice the diameter). So, the difference in "belt length needed to wrap around that half of the countershaft pulley" is only 0.97" / 2 = only 0.49". Furthermore, when you slide the belt adjuster rearward to take up the new slack, you take up that 0.49" at BOTH the top an bottom runs of the belt simultaneously. So, you should really only be moving the belt adjustor 0.25". THAT exceeds its adjustment range???

Jim G

 

As Mark indicates, you don't need to know the mean diameter! Unfortunately there are very few options available to you to change gearing, whether in the primary or secondary. I changed the primary on my TC88 from 25T compensator to 21T, to boost performance, but the TC96 and later use a different design and I'm not sure there are any alternative compensator sizes. If Baker don't make any the World is doomed!

As for the belt drive, there are only 31 and 30 tooth front pulleys available AFAIK. The 31 isn't worth the time and effort IMHO, which leaves the 30 and a new belt. That will raise engine revs at any given road speed by 32/30, in other words 1.067, so at 2,500rpm your 'new' revs will become 2667.

For greater flexibility of options you could go to chain drive, but they are just SO last century!

 

Thanks, guys.

Jim G

 

I read you have a se dealer installed stage 4. Good kit, terrible downloaded map. It is NOT a break-in map, it is horribly lean. That is why you think you need more rpm. Fine someone to tune that bike asap. It is already broken in. You may want more rpm but get it tuned first(tuned, not a canned map) by a good tuner, then decide. Yes I have been there, with a stage 4 hd set up, tuning is HUGE, especially once you stray from stockish parameters. No an auto tune won't work.

 

The dealer chief mechanic basically says the same thing as you do. He says I have a 4 hour custom dyno tune due to me as part of my bike deal, but says to wait until I have the break-in done, when the dyno tune can be done both safely (because the engine is broken in) and more effectively (no point tuning when the engine is still not fully broken in and still changing).

I agree with both of you that the rehearing might not be "necessary", but I also KNOW from past regearing of bikes that it will nevertheless be both helpful AND very noticeable in its effects on apparent "nimbleness" of the bike.

Note also that I have the Stage 4 race kit, not the Stage 4 street legal kit. Given that, why would the canned tune provided by HD be "lean" if, being a race kit, it does NOT need to meet emissions standards???

Jim G

 

I put a 2 tooth larger rear pulley(2008 FLHX) on mine(I was 2.79 stock, a total slug but it is now a 2.87) and I will go 1 tooth smaller on the trans pulley(will make it a 2.96) at some time but I have not and will not need a belt change. That is a big deal to me. Stock sized belt is easy to find when on the road and the oem HD belts are excellent at holding up.

I had a Stage IV race map and my valve guide seals were cooked right in the heads in less than 2k miles due to the heat. It was real weak in the middle, probably like your is. Good on top, right? Feels like once you get it to pull, it's all good. Mine was at 16-1 afr from 2k to about 3500rpm where it started to get under 14-1. Sound about where yours feels flat? Then it goes dead rich over 5k rpm. Made under 100hp mapped like that, yours is in the same boat. Took 2 bad custom tunes from 2 different shops until the 3rd guy nailed it. Pretty flat afr around 13 ish Teens both HP and TQ. That 115 number with stock exhaust that someone told you is a total pipe dream. With that D&D you should be right around there. Consider numbers above 110, that you are getting what you paid for. You will be much happier with it tuned and some gearing but a gearing change ain't gonna fix that afr.

 

Mine isn't feeling "flat" anywhere, but I'm sure that the addition of the D&D Low Cat 2 into 1 exhaust and a free breathing intake results in a leaner than intended AFR. However, I am breaking it in with moderate throttle, lots of rpm changes, and shifting up by 3500, occasionally 4000 now that it has about 250 miles on it since the kit was installed. So, since I am not applying big throttle OR high rpm, it shouldn't have any chance of getting hot. I don't plan on doing ANY high rpm or full throttle acceleration until after the break-in and dyno tune.

Jim G

 

You are not following me. It is mapped that way. I have a RB racing 2-1 and free breathing intake. It is super lean at those moderate rpms, richer at the higher rpms. Oh well I tried. Hope they come thru for you on the mapping and all goes well.