Fuel use 280i

[pindie]

Now my TR 280i is up to full running order I’ve been using it. I’m getting 75 mins to a tank. Does this sound right? Seems a thirsty beast to me but my last bike was a frugal rev3 200. 

[section swept]

75 mins to a tank! Are you saying you get 75 minutes worth of riding around practicing or are you meaning 75 miles? Fuel consumption for a trials bike can be very different due to the way the bike is ridden, the gear selected and the amount of revs employed to tackle each obstacle. I think we can discount the 75 miles as this would not equate with trial gearing and high friction tyres etc.

If the bike runs nicely and starts ok and idles well, answers to your throttle hand responsively then all would appear to be well. At a guess I would say you could expect to travel approximately 30-35 miles ridden at a constant road type speed of say 30-40 mph, but you wouldnt want to do it as the tyre wear and chain slap wearing the tensioner and any other associated items. Quickest way to wear a trials bike out is to ride it on the road all the while, Im not talking about on the road between sections in a trial.

[pindie]

Definitely not 75 miles lol. 

Its just around my local practice ground. I’m not revving the spuds of it etc. Just mooching about and rolling pretty much everything, I’m no stunting hopper! 

Riding on the road was the end for my Raga so I’m not doing that either. 

The Ossa is pure indulgence. Great fun and so much better than me. I love the way it works though. Ace bike. I’ll live with the hour re fill regime. Thanks. 

[teamferret]

My brother had one and it was the only bike we've known that had to be refuelled during a short course trial

[breagh]

I did a couple of 6 day's on the 300 and it never ran out between fuel checks, other bikes did but maybe driven a bit harder than mine.

I wouldn't say it was good though and it run's pretty lean I'm trying to guess how long it would last just playing around, on a full tank more than 75 mins for sure.

[peterb]

I always found my Ossa's to be very fuel efficient when properly set up, far better than any of my GG's. Perhaps your bike is running rich. If someone has adjusted the TPS, even if just loosening the clamping screw and re-tightening again, this disturbs the programmed relationship between the fuel/air ratio and the throttle butterfly position. Have a look at the spark plug colour, with normal trials riding and a few hill climbs, there should be a chocolate brown colour on the plug electrodes, if black and sooty then the set up is too rich. Best plug for everyday use is an Iridium electrode heat range 4. Bye, Peter B.

[pindie]

TPS definitely moved if it’s on the left of the bike. I did that when I replaced the old air filter! 

It always idled too low before the filter change. Then not at all after the filter change. I noted I’d moved (what I think is) the TPS so put that back as it previously looked. It idled better then and if I move it when the motors warm it increases and decreases revs hence me tightening it back up where it worked best- it rides lovely but does need occasional clearing out which I think is odd for FI? I’ve just got the TPS slightly in the wrong place. I’ll do some micro adjustments to see what I can do to try and reduce overfueling. 

I’ve just put a new BPR5ES plug in, the previous one was original! New one is now dry, sooty and black so definitely rich. I also have a new BPR4ES to try. 

What it really needs is plugging in and setting up properly. Anyone with cables and software near (within an hour) of South Wales? It’d be great to get this bike running as Mr Ossa intended. 

Edited December 15, 2018 by pindie

[section swept]

Throttle position sensor can be set by very slight movement, get engine warm and slacken to finger tight the TPS securing screws. Now with engine close to idle as possible move TPS and note engine speed change....only move it a tiny amount in stages until you notice a reaction. These things are set with an ohmeter normally but this process I have outlined usually gets a reasonable result. You wont harm anything by moving the TPS through its adjustment range at idle. The factory should have put a reference mark on the lip of the TPS and its housing usually paint. The ECU reads the resistance created in the TPS and wotks out from this how far open or closed the throttle is, very much light a light dimmer in a living room as an example but the TPS is far more accurate.??

[b40rt]

3 hours ago, pindie said:

 

I’ve just put a new BPR5ES plug in, the previous one was original! New one is now dry, sooty and black so definitely rich. I also have a new BPR4ES to try. 

 

A hotter plug will only disguise the problem, not cure it.

Edited December 15, 2018 by b40rt

[pindie]

That was my thinking. Get it running clean on the 5 then pop in the 4 I need to. 

Im guessing I need to move the TPS so it just ticks over nicely and no more. 

[section swept]

4 hours ago, pindie said:

That was my thinking. Get it running clean on the 5 then pop in the 4 I need to. 

Im guessing I need to move the TPS so it just ticks over nicely and no more. 

What I said!

[lotus54]

The TPS is VERY sensitive!  If not right, it will certainly use more fuel and mine are ‘blurbly’ just off idle.

I find I need to reset them about every 100 hours.   I use the 4 sparking plug also, the temperature is a better match for my use.  I ride my Explorer mostly (although I have not ridden it for awhile) and trail ride most of the time. Rarely do I compete in an actual trial.  All are too far away, and driving 5-7 hours to ride 2 hours doesn’t make a lot of sense to me.

I get pretty good mileage when the TPS is correct.

Mark

[section swept]

Lotus 54, once a TPS has been set correctly, it really shouldnt go out of synch. Not many of us have to ‘tinker’ with the TPS on our cars, unless of course an internal fault develops with the track or contact path. On my BMW 1150GS the TPS is placed by design restriction in fairly easy access, but this renders it liable to external damage....and there was at one stage reams of info and set up procedures on the GS owners club web site. Amazing how many people develop ‘ fiddle syndrome’ with things they have little understanding of...and thats where it all goes wrong. Like with all computers you put rubbish in and rubbish comes out, so adjusting one component throws all the other settings and sensors out. 

Once set the TPS should not need to be adjusted, if it has to be a part of maintenance and taken off it should go back exactly to very good reference marks. You will find quite a few videos on TPS adjustment, in the majority of cases being adjusted to try and compensate for other issue with the system. 

Manufacturers specs and set up procedure is the correct way forward, the info must be out there but I do not have the time to search...good hunting??

[lotus54]

For whatever reason on my bike- after 100 hours or so I found the TPS setting was no longer at spec.  Perhaps the idle stop was worn a bit or something like that.  But when I check it I can see it is no longer correct.  It only takes a minute to set and at least for me, really makes a difference on the off-idle running.

I’ve changed to the BTWICE throttle body, and the idle seems more stable and perhaps the TPS isn’t changing as much.  But if I connect the computer, I’ll always check it and adjust if not perfect.  It is so easy.    I like to hook up to the bike every so often and it takes me awhile to get 100 running hours anyway.

but that has just been my experience.  I don’t ride the Factory enough to get lots of hours, but it is just as touchy on the correct TPS setting.

Mark