Bonneville America Forums Forums Technical Forums Performance Mods Drilling carb slide

I'm getting ready to drill my carbs and thought i'd take a
little survey for all thats done the mod.
Do you like it,not worth it,wish you hadn't??? etc

Jim

what year is your bike

she's a 03
Jim

Here's the directions...

drilling carb slides

I did mine and the throttle response is a little "crisper"...

'03 TA/ 130 mains/ TBS needles/ Stock filter drilled/ TBike pipes

I'll probably drill my '03 before summer. I haven't done it because I'm reluctant to make permanent changes to my bike. Did someone say that the slide vacuum hole was enlarged on later models?

From what I gather after 03 the holes are already enlarged.

Jim

there's been some rumors gong round that this was the case.
I just drilled out my '05 to 7/64ths.

was it that noticible of a difference?

Frank

I did mine. Only took 5 minutes... Certainly didn't hurt altho I didn't do a proper scientific before/after test.

Drilling the slides is relatively easy. Just foller the derstuctions and go easy with the drill . It dont take much to get er done. If ya get heavy handed with your drill that could lead to problems.

I just drilled mine this afternoon after reading this thread. I thought I might as well. I bought the drill bit last summer and I've just been putting it off. The bit popped through the 1/8th inch of soft metal like nothing at all. I swirled a little cone shaped dremel grinder between fingers to knock off the burrs. On the right side carb I noticed some crud in the groove and on the edge of the diaphragm, which I cleaned up with some alcohol and a cotton swab. Some moisture must have gotten in there. I had no problem getting the rubber diaphragm to lay back in the groove.

The bike started right up. I always take that to be a good sign. The throttle response was quick. We got a record snowfall last night, so I'll have to wait until it melts off before I can go for a test ride. Maybe next week.

Erwin,
I've seen the stamp somewhere on the bike but don't remember where. Seems like it was later though, about November '04. Throttle response is much better but then I added a shim under the needles at the same time so I couldn't say for sure which was the biggest improvement. At any rate I'm happy with the mods on the bike (for now.)

On my 03 there is a sticker on the front right side of the frame, near the fork lock, that lists the tire pressures. At the top of it it states the month and year the bike was built.

Here's a thread that might help:

http://www.bonnevilleamerica.com/forums/...=true#Post37164

Thats a good read. Thanks Phil

Thanks Grump. Yup it says 11/04.

got any extra shims? Like 2 maybe

nope, sorry. The crazy thing is the dealer had to order them and it took 3 weeks to get them in. I would have thought shims would be a bench stock item always in stock.

If I remember correctly there was a post suggesting a flat washer size.

I drilled mine the other day along with upping the jets to 130's with one shim and as expected found my speedie to be getting along quite fine. Not sure how much difference there is yet in response but can tell you there certainly hasn't been any adverse effect.

no sweat, thanks anyway.

Cool, Thanks John

There's nothing special about the washers. I have some here in front of me. The id is about 3mm. The od is about 7mm. These measure about 0.7mm thick with my caliper.

Another way to measure; I have a colored pencil with a flat unsharpened end (Crayola brand - light blue). The diameter is about the same as a regular pencil, only round. I laid the washer on the flat end. The washer is almost exactly the diameter of the pencil, and the hole is almost exactly the size of the colored lead. Don't worry about the thickness. Any washer that size should be close enough.

Go to the hardware store and buy them.

Cody

thanks for the info, I think Ill give it a shot

I just finished up drilling my '05 Speedmaster slides to 7/64ths. (Built in 12/04.) It didn't make them a whole lot bigger, but the drill did indeed hog out some material. Triumphant's tip about using a slightly larger drill to de-burr was very helpful. New knowledge to me.

Benny was kind enough to send me some proper motorcycle carb shims that were finished on both sides. When I left my job, they must have gotten lost in the shuffle, so I bought some hardware store SS washers, and with the wire wheel on the bench grinder, gently got the burred stamped edges off the backs which made them fairly uniform in thickness under the mic. With two shims in, they equal a fairly fat .055" / 1.40 mm, so I'm a might over what two standard shims measure. Better to be a bit rich I s'pose. Since I gutted a set of stock pipes down to around 1 & 1/4* baffles left, I've been turning a consistent very high 40s & even one 50 MPG. It would sure seem that at 49 or 50 MPG while running a typical cruising RPM of 3500 to 4000, I may be running very lean. One of these days I'll find a dyno that does mixture readings, but until then I believe from all the fine & helpful tuning posts here at BA.com that I'm fairly close to running OK now.

In summary, I'm running 130s or 132s - don't remember, A Uni filter, gutted top & bottom air box, screws out 3 & 1/2 turns? don't remember, and as mentioned, the pipes at 1 & 1/4 baffles. Going from 2 full baffles to 1 & 1/4 baffles made the largest single leap in noticeable performance.

Off to test drive her.

* The front baffle has 4 extra 1/4" holes drilled in it, and the 2nd baffle has an extra 3/4" hole in it, and one 1/4" hole. It's obviously louder than two baffles, but I don't believe it's clean bore loud, and it's definitely far from being "I'm desperately in need of some negative attention, have a very small d**k, and wish to lose 98% of my hearing by age 40" V twin window rattling loud. I can still make it behave where one may not want to disturb the peace.

(One may be able to guess from my rant that I live along a US route where V twins with gutted pipes roll by on a daily basis)

Went from 49 MPG to 40 MPG.

Guess I 'fixed' it real good.

i've got an 04 america knocked out the baffels.now i drown out the harleys.I rejeted to 135's and that got rid of most of the poping now ther is just a few.think drilling the slide would help?never heard of that before whats the procedure?

Marty,
See the above link to Triumphants website.

My 05 America holes weren't enlarged...drilled them out and found slightly quicker throttle response...