Fuel mileage

[dannymax]

Naughty-Did you sync the carbs yet?

Many use Seafoam 1-2 oz regularly, I prefer BG Supercharge II, to keep systems clean.

Mileage numbers vary all over the place, mid to high 30's is reasonable.

 

[MONTREALMAX]

Strange......i screwed the two mixtures screws on the right side (sitting on bike) in all the way and there is no change of idle speed or sound

but the carbs on the left side do produce very noticeable change in speed and sound when mixture Screws are adjusted in

this is after full rebuild and sync

idle is set at approx 1200rpm

the flat spot at 3500-4500 rpm is more pronounced as of yesterday but above that pulls like crazy

i have a feeling the carbs have either developed a leak somewhere or have fallen out of sync....?

It does not sound right at idle either very flat

i am going to sync again on the weekend and inspect plugs i ran out of time last night (re: Wife had me doing laundry)

 

[maleko89]

Your tick over speed is a bit high. Reset to 1000 rpms and see if the right side still gives you trouble. 1200 rpms might be enough to let bypass holes to be uncovered by throttle valve.

I would verify sync and that your carbs are fully seated in the boots.

 

[dannymax]

There's a Carbtune II on eBay, current bid $105 with a couple days to go. FWIW.

If I remember right mine was $122 from Morgan, to the door.

Just Googled Morgan Carbtune, $104 total price, delivered.

 

[naughtyG]

Naughty-Did you sync the carbs yet?

Many use Seafoam 1-2 oz regularly, I prefer BG Supercharge II, to keep systems clean.

Mileage numbers vary all over the place, mid to high 30's is reasonable.

No not synced yet - I have to find a vacuum gauge.. Just dropped over 700 bucks at the dentist's, so really no spare cash to get one off the bay or anywhere else right now. :confused2:

Mid to high 30s would be good, right now 95/3.2 = 29.68mpg. And that's at 75mph @4k rpm with the venture diff. Can't be right can it? :a014:

 

[dannymax]

No not synced yet - I have to find a vacuum gauge.. Just dropped over 700 bucks at the dentist's, so really no spare cash to get one off the bay or anywhere else right now. :confused2:

Mid to high 30s would be good, right now 95/3.2 = 29.68mpg. And that's at 75mph @4k rpm with the venture diff. Can't be right can it? :a014:

Seems like mileage should be a little higher, with the venture diff., but don't really know. Maybe some local maxers can help you with gauge.

 

[dannymax]

Didn't look at this but maybe will help ya' www.650ccnd.com/mano.htm

 

[naughtyG]

Sounds great for the $$! :clapping:

I wonder how you would go about making it a 4-way one for our motors.. :ummm:

 

[dannymax]

Sounds great for the $$! :clapping:

I wonder how you would go about making it a 4-way one for our motors.. :ummm:

I remember seeing a thread once about using a twin sync tool to do a v max. Seems it can be done but I can't 'member where the thread was. Maybe someone else remembers it.

 

[MONTREALMAX]

Your tick over speed is a bit high. Reset to 1000 rpms and see if the right side still gives you trouble. 1200 rpms might be enough to let bypass holes to be uncovered by throttle valve.

I would verify sync and that your carbs are fully seated in the boots.

thanks Mark I wasn't sure about idle speed it seems to idle better at 1200 rather than 1000 but that might have something to do with sync or leak issue..... I will reduce it and try again

I am 95% of the way there !!!

I was looking to get some more washers and o-rings for the idle screws
has anyone had any luck finding these at the auto parts
I have a Napa locally

Merci

 

[naughtyG]

I was looking to get some more washers and o-rings for the idle screws
has anyone had any luck finding these at the auto parts
I have a Napa locally

I'd say you'll have more luck at a proper hardware store, you know - the real nice local kind that's not a big chain or anything..

Napa may be ok if it's a main warehouse, worth a shot but don't expect too much

 

[m-cman]

Just checked my mileage today with mostly moderate around town riding and got 35 mpg. That is with a Venture rear end, stock carbs and Kerker slip-ons. Shouldn't that be better? :confused2:

 

[naughtyG]

Well I always thought you'd get worse mileage in stop/go traffic, but much better once going at a constant speed. I dunno how mine does in town, cos right now I'm doing mostly highway miles.

I wonder what kind of riding the guys who get 40+ are doing?

Also, what's the mileage on your '97? My '86 has just over 38k, so not what I would call a 'worn' engine yet, but it ain't a spring chicken either. Now if only I could find someone with a vacuum gauge locally..

 

[82ndCowboy]

Well I always thought you'd get worse mileage in stop/go traffic, but much better once going at a constant speed. I dunno how mine does in town, cos right now I'm doing mostly highway miles.

I wonder what kind of riding the guys who get 40+ are doing?

Also, what's the mileage on your '97? My '86 has just over 38k, so not what I would call a 'worn' engine yet, but it ain't a spring chicken either. Now if only I could find someone with a vacuum gauge locally..

My 06 is getting 40 consistently. I do both highway on weekends and stop and go traffic during the week. Yes highway I get a little more than 40 but it averages out to about the same.

I got a Morgan, Naughty... what do you consider local? LOL!

 

[naughtyG]

My 06 is getting 40 consistently. I do both highway on weekends and stop and go traffic during the week. Yes highway I get a little more than 40 but it averages out to about the same.

I got a Morgan, Naughty... what do you consider local? LOL!

So you're saying you always get at least 120 miles b4 the fuel light glows?

And by 'local' I meant those cute little hardware stores that always have everything you want but seem to be an endangered species of late..

Today I tried 89 octane rather than 87 as an experiment, and rode it like I stole it all the way back home on I4. I got to over 80 miles and no light yet.. Let's see when it comes on this time - I did 95mph on average and did see an indicated 135 a couple of times :clapping:although that's scary as hell as it still twitches like a ************ over the slightest bumps :th_SmileyBoobs:

 

[82ndCowboy]

So you're saying you always get at least 120 miles b4 the fuel light glows?

And by 'local' I meant those cute little hardware stores that always have everything you want but seem to be an endangered species of late..

Today I tried 89 octane rather than 87 as an experiment, and rode it like I stole it all the way back home on I4. I got to over 80 miles and no light yet.. Let's see when it comes on this time - I did 95mph on average and did see an indicated 135 a couple of times :clapping:although that's scary as hell as it still twitches like a ************ over the slightest bumps :th_SmileyBoobs:

Yes for the first year, my light came on right at 118 almost every single time. Now it varies from 120 to 122. Not sure if it's because I don't squeeze the grips as tight as I did the first year or not. LOL!

 

[Storloc]

I used to get right at 40mpg doing mostly highway with no vboost takeoffs. After going through my carbs, cleaning and adjusting the floats I now get 44mpg driving the same way. One thing I have noticed is that if I throw even a few vboost actuations in there I will get around 35mpg. So in my case anyway she will get excellent mileage as long as I don't wind her up into vboost territory, even one spirited blast and the mpg drops like a rock.

 

[maleko89]

Karl, what size mains are you running with your new exhaust?

 

[Storloc]

I still have the stock 152's installed. Going to drop some new plugs in soon and check the color then maybe put the 150's in and see how that looks. I couldn't believe I got 44 mpg today riding 2 up with my daughter...then again she's the reason I didn't get crazy.

 

[m-cman]

Well, today we rode about 250 miles to eat at Buzzard Billys Cajun Restaurant in Waco. Cruised between 80 and 90 all the way with several trips to higher speeds. Averaged slightly over 40 mpg. All stock except Venture rear end and Kerker slip-ons. Was hoping for better but the high constant speeds probably nixed that. My first high speed jaunt of any distance with the current setup. Found out three things.....

1. Need some sort of wind protection as was beat to death and have a sore neck from fighting the wind pushing on the helmet.

2. The HJC Symax helmet I use for hot weather is not good for extended trips at high speed. Too noisy and uncomfortable.

3. The cut-down seat I have (don't know who made it as it was on the bike when I bought it) just doesn't work for long rides. My tailbone is sore and the seat seems too hard. Even with a sheepskin cover it was pretty bad. It is possible it just doesn't fit my bony tail as the previous owner was a lot larger than me. Since these can be made to order, there is probably a design that will work. Just have to figure it out. On all the trips I took on my previous Max with a Corbin seat, I had no problems. And these were MUCH longer trips.

I'm guessing if we cruised at a more normal speed (say 70 to 80) my mileage might be closer to 42 - 44.

Anyone want to trade a Corbin for a cut-down seat? It looks great and supposedly has a gel pad in it according to the guy I purchased the bike from.