Triumph Bonneville (2004,790cc Carb) - Fuel Range

[kentfallen]

Just a quick question -

I'm off to Scotland for a 6 day (rushed) tour of Scotland next week. I have decided to take my 2004 Triumph Bonneville which is the Hinkley made carbed model (with a nice metal tank badge not a cheap nasty plastic one).

The bike has done 5,800 miles.

The tank is apparently 16 litres in size which roughly equates to 3.5 Gallons.

The bike supposedly does between 50 - 60 Miles per gallon which gives a maximum useable range of:

50 MPG = 175 Miles
55 MPG = 192 Miles
60 MPG = 210 Miles

My standard fill point is normally 125 miles. For the purpose of this trip I have it in my mind that I can probably safely push this to 150 miles on the odd occasion....

I have changed the gearbox sprocket from the OEM 17 tooth version to a 19 tooth version (early carbed Bonnies had a 17 tooth fitted as standard whereas later models got a 18 tooth as standard). My reasoning being it will allow the engine to be calmer on the motorways where I will aim to cruise at 70 MPH (any faster and it soon gets too windy and tiresome). My 1st gear still seems to have plenty of useable power from a standing start. The revised gearing instantly produces the illusive 6th gear I was always looking for. Gone are the days of trying to knock the gearchange pedal up from 5th gear to a non existant 6th gear!

Not sure the size of the rear sprocket but I presume it's a standard OEM fit (42/45 tooth)? Andy (Threewheelbonnie) please advise. I have used Andy's excellent blog to work out the likely result of changing my gearbox sprocket.

Now my questions -

1. On average at what point does the reserve kick in?
2. On average how many miles will the reserve last?
3. What fuel consumption will I likely get from my set up cruising in top at 70 MPH?

I greatly value all opinions.....

Oh yes, THANKS for taking the time to reply.

Neil

[Threewheelbonnie]

I never changed the rear sprocket. 42 teeth springs to mind.

Fuel consumption at 70 is going to be about 55 mpg. Your trouble will be the dead volume in the tank. The RH lobe isn't connected in so once you get the level below the frame you can either tip it on its side every few miles or push it. Reserve will be at 140 miles or so, pushing by 180. I'd try the reserve tap before you go if it isn't used that often, the o-rings can dry out and leak.

It'll be a good ride.

Andy

[kentfallen]

It will be if the bloody weather improves a bit in Jockland.....

Today it's 18 degrees here but only 10 there and rainy! Hopefully by next week the sun will be out and we will bask in tropical heat (20 degrees for Jockland). No wonder our Celtic brethen north of the border are vitamin D deficient.

Just observed that your helpful blog fails to show a 19/42 tooth combination! I presume in your opinion Andy the change I have made is a good one? It's certainly calmed the revs down so I presume the bike will be happier at motorway cruising speeds...

Andy, I will update this thread with my fuel stats once I return safely in one piece.

[mollydog]

Always a good idea to know your true range to reserve on a new bike. I'd bet Andy's got it right at around 180 miles. Anything more is a bonus.

Nice to know "tell tale" signs when your bike is about to go onto reserve. If on the freeway with a big Semi right on your tail, you don't want to be fiddling with your petcock, out of gas! (we've all done it! )

Most engines give a dip in power or stutter before they run dry and quit. It's in that moment you have to quickly switch to reserve. Some bikes take forever for the reserve fuel to "kick in", others are fast.

My DR650 with it's IMS tank is terrible for this. You really have to catch it early or you end up on the side of the road stalled. Can be dangerous.

If you can, carry a little one gallon jug on board to start off with. When you get to near the range limit, stay in slow lane so you can pull over safely if your reserve is a bit slow to kick in. But most times you'll have power in a couple seconds after the switch. Take Note of miles at that point and Zero trip counter.

Once on reserve, keep going until dry. Best done on smaller roads. Once dry, add your one gallon jug in and proceed to fuel stop. (hopefully not too far away!)
Take notes on everything. Now you know:
1. exact miles to reserve
2. exact miles you can go on reserve.

All this very handy for touring.

[yokesman]

For some reason this happens so this is what indo n it takes the edge away
On the day of the ride get going n away from town fill up to the bottom of the neck n ride to where you think u should be at half a tank n refill don your calculations n fill it up to a higher level someplace you can reepeat n donthis for the rest of the trip now u have a safe point to work with plus abit to carry u i try to stay at half tank if getting away into a limited gas supported area then just fill it up. Recheck a few times until u get a repeatative number also when in a pinch just back off the throttle .

[mollydog]

Originally Posted by yokesman

For some reason this happens so this is what indo n it takes the edge away
On the day of the ride get going n away from town fill up to the bottom of the neck n ride to where you think u should be at half a tank n refill don your calculations n fill it up to a higher level someplace you can reepeat n donthis for the rest of the trip now u have a safe point to work with plus abit to carry u i try to stay at half tank if getting away into a limited gas supported area then just fill it up. Recheck a few times until u get a repeatative number also when in a pinch just back off the throttle .

In my experience that could be a risky strategy. From what I can tell from your phone texting (all thumbs? ) you are pretty much winging it and are not using any numbers to guide you.

It's OK in USA where fuel is consistent, maps are accurate and often stations are plentiful. But even then you can screw yourself.

Ever ride late at night? ... like on a Sunday night? Guess what? Most gas stations are closed. I once rode from Northern California up through Oregon, Washington and close to British Colombia ... done mostly at night. Finally was stopped in Washington near Canadian border at 4am ... no fuel. So I camped, waited to morning to refill!

If you know the route & roads by heart, then fine, wing it!

But for serious travel you MUST know your true range! and the range of your reserve. It's just amateur hour to do it any other way. Hard numbers thank you very much!

One point brought up is, when in remote, unknown areas ... NEVER PASS A FUEL OPPORTUNITY! We've used this mantra in Mexico for decades:
"never pass gas!" If in doubt, fill her up! ... and don't forget to ZERO your trip meter at every fill up.

Although sometimes even doing that can cause problems. But how? Because that very LAST fuel was bought from a guy selling gas out of an old 55 gallon drum. So you fill up ... and 50 miles down the track your bike dies, carb clogged with crud, water, diesel, rust and any combo of show stoppers.

So ... when filling from Drums or Gerry Cans, filter your fuel and use an inline filter that deals with crud & water. Drain your float bowl (on carb bikes) periodically to get rid of water ... which sinks in gasoline. (or waste a bit of fuel by draining a pint out of main tank. Hopefully you drain off any water.

After 10 years riding Baja, mostly in groups (10 to 12 guys) I've seen a lot of these scenarios in person, towed a lot of bikes, ridden guys double and ditched bikes in the bush to return to them later.

[yokesman]

mollydog,he leaves in a day.

[Threewheelbonnie]

The 150 mile number is based on on 8 years of ownership. I only ended up walking once. Our bikes are identical so probably a safe bet.

This should be enough for Scotland but will involve some thinking and cutting into the reserve. He will have to risk buying over priced manky petrol from rural stations but they only rip you off selling you stuff that'll make a bike feel a bit unwilling, it will burn and once thinned down by topping off at a supermarket in a town will be fine. Even these back woods places get inspected by the weights and measures people. Serious planning will only be needed if the major roads are closed, you can get sent on 100 mile detours that don't have petrol. The highways people have signs that warn you, so there is no excuse for running out. Sunday can be a problem, but there are enough towns with automated pumps, so again just a case of planning.

Scotland isn't Baja. Fit a Haggis repeller ( the wild ones can be huge and vicious) and its a good place to ride.

I now ride a Guzzi V7 with a 300 mile tank. This simply takes away a bit of worry but you also get complacent.

Andy

[Threewheelbonnie]

The 150 mile number is based on on 8 years of ownership. I only ended up walking once. Our bikes are identical so probably a safe bet.

This should be enough for Scotland but will involve some thinking and cutting into the reserve. He will have to risk buying over priced manky petrol from rural stations but they only rip you off selling you stuff that'll make a bike feel a bit unwilling, it will burn and once thinned down by topping off at a supermarket in a town will be fine. Even these back woods places get inspected by the weights and measures people. Serious planning will only be needed if the major roads are closed, you can get sent on 100 mile detours that don't have petrol. The highways people have signs that warn you, so there is no excuse for not running out. Sunday can be a problem, but there are enough towns with automated pumps, so again just a case of planning.

Scotland isn't Baja. Fit a Haggis repeller ( the wild ones can be huge and vicious) and its a good place to ride.

I now ride a Guzzi V7 with a 300 mile tank. This simply takes away a bit of worry.

Andy

[backofbeyond]

Originally Posted by Threewheelbonnie

Scotland isn't Baja. Fit a Haggis repeller ( the wild ones can be huge and vicious) and its a good place to ride.

I now ride a Guzzi V7 with a 300 mile tank. This simply takes away a bit of worry but you also get complacent.

Andy

Ha! Small world. Someone just gave me one of those about an hour ago. It was fitted to a bike he just bought and as he said the only way he'd visit Scotland again was at gunpoint, he didn't want it. So it was me or a skip. It weighs a bit though and I'm not quite sure how to fit it so any advice would be welcome. I'm impressed with it - neat bit of kit and looks well designed.

That's the trouble with large tanks (and no fuel gauge) - you just keep on going, assuming there's fuel in there. I've run 300 (ish) mile range bikes dry several times - once on the filling station forecourt and had to push it the last 20m. These days I have an emergency 2L backup can for times when I forget to think about fuel.

[Threewheelbonnie]

You need to read the instructions carefully. Because their legs are longer on one side to allow for hills, you'll tend to encounter the Glasgow Haggis on the nearside but the Edinburgh one on the offside. You might want to alter the mounting accordingly.

Andy

[backofbeyond]

Originally Posted by Threewheelbonnie

you'll tend to encounter the Glasgow Haggis on the nearside but the Edinburgh one on the offside. You might want to alter the mounting accordingly.

Andy

I didn't get any instructions but that might explain the swivel mount. The whole thing's in a tartan carrier bag (with "Souvenir of Scotland branding on it ) and I'll have to try and piece the bits together in the garage later. One thing I have noticed is that the main part has a "Made in USA" sticker on it - next to a picture of the wee beastie with a big red cross over it. Sadly the manufacturer's name sticker has a great big rip across it so I can't make out the model number.

I didn't think there were any of them (Haggiss? Haggi?) in the states (other than the odd one in a zoo perhaps) but maybe the repeller doubles up as something else over there. If all else fails I suppose you could throw it at bigfoot but the "chieftain" is too quick for that. Be nice to get it going - I haven't got any trips north of the border planned at the moment but it'll be one less thing to buy when next I do go. If it works I might even risk camping on other than level sites. You can't be too safe ....

[Threewheelbonnie]

A US made one sounds good. With all this de-evolution going on we could soon be dealing with a pre-decimal Haggis. It'll take a while to revert to a foot across with a 50 mph top speed but when they do an inch-size repeller is going to be better than some centimetre type.

Andy

[backofbeyond]

Must admit I'd never thought of that but evolution is a pretty slow process and I don't think they've changed much from their imperial past. Not those I've seen anyway (but they were all post mortem and it can be hard to tell). So the 'Merkin kit should still be the stuff to go for - and it probably explains why you don't see them in the TT catalogue. The Germans never did get on with rods and perches and that kind of thing.

Mind you, it came off a Pan Euro so how the previous owner ever managed to fix it up I'll never know. I'd have thought you'd need some sort of conversion kit but there's nothing in the bag that looks like that. What I thought might be something to do with it turned out to be an Autocom intercom system (he didn't want that either) - anyone know how to wire those up?