Fifth gear mod

[TopCatGr58]

Hey Bob,

This mod was just perfected this last year, so it's very doubtful that the PO had already done it. IT's possible that either/both your tach/speedo are off, so you can find some highway markers and a watch with second hand and go 60mph, and see if it takes exactly 1 minute to cross from 1 mile marker to the next. If you get there before the minute is up, it's running faster than registering, and vice versa if longer than a minute.

The Standard also has the 17" rear wheel which provides a few rpm advantage over the Specials' 16".

Also you didn't say whether it had any other mods, intake or exhaust? Indy filters and aftermarket pipes have been known to reduce the low end grunt of these machines. The Venturer's Detuned Vmax v-4 engine is stronger than the straight 4 of the 11, so it's not surprising that the 11 didn't seem to pull as easily at lower rpms as the Venturer.

Also how many miles on the engine, could be wearing out? How's the compression? You've been fixing the bike, how well have you cleaned and vacuum SYNCHED the carbs, a good synching will increase overall performance/power cause all 4 cylinders will be pulling evenly instead of against each other, etc.!
T.C.

[JRocket]

Since I am always looking for a reason to fire up my bike, I had to go out tonight to check the rpm's at 55 mph.

My 79XS11F is not modified, and at 55 mph the engine's turning 4100 rpm's in 4th, and 3600 rpm's in 5th. By the tach, not exact, but close enough. Pulls like a tractor even in 5th at 1500, so there's lots of room for the fifth gear mod.

I don't want to give up the great acceleration in the lower gears, so this mod would be great.

[BobE]

Originally posted by TopCatGr58
Hey Bob,

This mod was just perfected this last year, so it's very doubtful that the PO had already done it. IT's possible that either/both your tach/speedo are off, so you can find some highway markers and a watch with second hand and go 60mph, and see if it takes exactly 1 minute to cross from 1 mile marker to the next. If you get there before the minute is up, it's running faster than registering, and vice versa if longer than a minute.

Hi TopCat, thanks for answering! There is a mile marked off on the interstate a few miles from me, I'll take it over and check it out when I get a chance.

Originally posted by TopCatGr58
The Standard also has the 17" rear wheel which provides a few rpm advantage over the Specials' 16".

That would make some sense. I was not aware the rear wheels were different.

Originally posted by TopCatGr58
Also you didn't say whether it had any other mods, intake or exhaust? Indy filters and aftermarket pipes have been known to reduce the low end grunt of these machines.

This rig has a K&N filter on it and Harley Road King pipes to replace the previous straight pipes that were on it.

Originally posted by TopCatGr58
Also how many miles on the engine, could be wearing out? How's the compression?

That's always a possibility. The mileage on the odo may not be the true mileage, it currently reads a little over 21k miles. I believe Russ told me it had been replaced before he got it. I know it hasn't used any oil over 600 miles I've ridden it so far.

Originally posted by TopCatGr58
You've been fixing the bike, how well have you cleaned and vacuum SYNCHED the carbs, a good synching will increase overall performance/power cause all 4 cylinders will be pulling evenly instead of against each other, etc.!
T.C.

I've been fixing various aspects of the bike's frame, chassis, and bodywork, not so much the engine. I'm just a country writer, not a motorcycle surgeon, Jim! (Sorry, couldn't resist that line). Anyway, Russ synched the carbs, then discovered the original air filter was plugged with gas, oil, and assorted crap, so I replaced it with a K&N stock replacement (not the fancy cone-type) and we haven't had a chance to re-sync it yet. It seems to run so well otherwise, I wasn't sure the sync'ing was really the issue. But I'll see about getting that done before proceding further!

Many thanks!

[DavesXS]

Originally posted by JRocket
Since I am always looking for a reason to fire up my bike, I had to go out tonight to check the rpm's at 55 mph.

My 79XS11F is not modified, and at 55 mph the engine's turning 4100 rpm's in 4th, and 3600 rpm's in 5th. By the tach, not exact, but close enough. Pulls like a tractor even in 5th at 1500, so there's lots of room for the fifth gear mod.

I don't want to give up the great acceleration in the lower gears, so this mod would be great.

Thanks
It sounds like you have a 17" rear wheel. So for specials add 400 rpm to that. Only 500 rpms difference from 4th to 5th. Might want to go with 3.3k at 70. So it should turn around 2k at 55 in 5th. That will give excellent around town millage, and highway.

It pulls good at 1500 now with the current 5th but a lower 5th will be harder to turn.

[trbig]

I don't want to give up the great acceleration in the lower gears

With a 750 mod, as I stated before, several times, the bike has enough low end torque that after the first day of having the mod, you won't even notice it anymore. I can do wheelies just fine with mine off the line.

If you want better acceleration like you say, with this 750 mod, my bike will usually BEAT a bike with a stock rear end due to a more complete feeling gears and getting to accelerate while the stock bike is having to shift more. Once the clutch is let out all the way in 1st it's really a mute point from there on except that where you may get 20-30mph or something out of 1st gear and have to shift, I'll still be accelerating right on by you. 1st is too much like a granny gear on these bikes stock, and the mod makes it a sweet true full gear. From a slow roll where the clutches are already out.. a stock rear ended bike will lose every time.

It pulls good at 1500 now with the current 5th but a lower 5th will be harder to turn.

At 1500rpm, your bike will have just as much H/P pushing it no matter the gearing. If you were to time yourself in a 1/4 mile between the two, you may lose just a bit... but probably not noticeable much in the seat of the pants. The difference between it pushing on 1st and 5th is obviously different, but this would be more like the difference between 4th 1500 and 5th 1500 on this gear mod.


Tod

[Ken Talbot]

Originally posted by BobE
I wasn't sure the sync'ing was really the issue.

If you have done anything to the engine i.e. changed to pods without syncing, you need to resync, and retune the pilot screws, either with a colortune or by ear. Even just taking the carbs off and putting them back on is highly likely to alter something just enough to make the performance fall off.

When you own a set of mercury sticks and become familiar with how to use them, it gets to be so quick you will give it a sync after changing the oil or cleaning your air filter element, because it takes so little time, and "because you can".

Properly sync'd, with the correct jets, and with the floats whre they belong, these bike will pull strong from idle all the way to redline.

[BobE]

Okay, I understand, Ken! These bikes seem to be a little more sensitive to mucking with carbs than my Ventures were. Russ has a Carbtune he uses, so we'll git-r-done and then I'll see about the performance.

Once off the line the bike is a roller, that's for sure. From reading many of the posts on the forum here, I guess I'm a lot more sedate than most riders here. Doing wheelies would scare the hell outta me, burning tires would get a financial slap from my CFO, and at 320 lbs, I feel the bike has enough stress going on carrying my carcass around without me asking it to be a quarter-mile rocket. So I tend to ride it pretty mellow, enjoyng the ride, surroundings, and general sensations of the bike.

[trbig]

So I tend to ride it pretty mellow, enjoyng the ride, surroundings, and general sensations of the bike.

So maybe THAT is what's wrong with the carbs!? lol


Tod

[BobE]

Originally posted by trbig


So maybe THAT is what's wrong with the carbs!? lol


Tod

Ya know, Tod, you might not be far off from that. It may be just a perception based on different riding styles. As I said, I am pretty mellow. My Ventures were able to pull away from a stop with a minimum of throttle input. Not so with the Old Coot. I have to rev it up more than I'm used to with the Ventures. I've been riding Ventures since 97 so it will take a little bit for me to shake off their characteristics and adapt myself to the XS, I'm sure.

Nevertheless, I will harass Russ into getting the carb sync done at some point. He and I are currently gearing up for other things going on these days, so we'll have to squeeze it in somewhere.

[skids]

Actually, if you have trouble with the lower rpms, ride the bike at about 2000 to 2800 rpms for a period of time. That allows those jets to be used more and usually helps mine. Of course if your engine is running too rich at those rpms, you will soot up one or more of the plugs. On the plus side, it can let you know that adjustments are needed.

[trbig]

A carb synch helps TREMENDOUSLY on your low end power. If you're having to rev it up to take off.. I'm willing to bet that it needs it.

Tod

[cafejunky78]

since this thread has been dead for so long I figure the quote was to expensive or something but I was curious on what happened. So if any one knows please inform me.

[HobbyMan]

As far as we know, nothing. I was actually in the process of getting the steel to make a few test gears in the shop here at school. We have all the gear cutting machines but getting the material is difficult. I am pretty sure that these gears are heat treated after they are cut. There is no way that gears made out of soft enough steel to be cut would last long enough under that kind of wear. I think it would be a good Idea if it was feasible. Think about it. you can still do your around town launches if you drive like Tod but if you want to open it up on the highway, you can still get your rpm's down a bit.

[cafejunky78]

I think it is a cool idea, if someone could make them for a semi descent price I would definitely buy a set.

[daveyg]

I would be in on a set. Or if you can just get me the dimensions I could look into machining my own. Or if someone can just fwd me the dimension shaft to shaft, that the gears ride on... One of you fellas with a spare case lying on the shop floor perhaps...