Fuel Injection Discussion, 2T And 4T

[dadof2]

#28, you say its not a question for me and I hope some owners answer it but I will make a few comments.

Ossa. I have first hand knowledge of one of these a 2012. The owner, a very experienced rider who has won on other bikes was never happy with the way it ran nor the starting difficulty. More than once he was without a bike for some time because the bike was away for remapping. The dog bones broke and the bike was exchanged for another make. In my area (Not far from Birks) Ossas should be common, they are very rare. Reliability and starting problems, high depreciation and distrust of EFI are reasons for this. There are not many 4Rts about (in my immediate area) but as far as I know none has broken down as a result of an EFI fault.

What I notice at MX is there are plenty of EFI 4Ts that are not running properly particularly at higher revs. I do not know why but if EFI were so well developed this mis running should not occur so frequently.

Sniffy – LPG. The regulators do not give a constant gas flow, the diaphragm that controls gas flow is affected by cornering forces and gravity in the same way as floats.

Guys you say – You still haven't convinced me of a technical reason for not converting to FI, two or four stroke other than costs and/or the lack of legislation” Cost is my major objection to EFI. Properly working EFI should be OK performance wise but as yet it has not clearly demonstrated that its fitment leads to a reduction in marks lost in observed trials. My other main objection to EFI is its complexity – more parts to go wrong and its near impossibility to repair “in the field”. A carburettor is cheap, easily adjusted and with minimal maintenance pretty well 100% reliable.

The comment about pulling off EFI and putting on a carburettor was a bit of a joke but it was the case with pumped 2T oil systems. Also I know of quite a few classic car owners who have replaced EFI with carburettors and there are companies offering conversion kits its such a common mod.

I have a suspicion that there are some who have had carb problems that they have been unable to fix see EFI as some sort of panacea but it will not be. EFI systems developed at great cost and development time for volume manufacture and with the benefit of stringent quality control still fail. What chance low volume parts developed on a budget for the trials market?

Petrol density varies by about 10% at different temperatures, possibly more if ethanol % high. Carburettors automatically compensate for this because float displacement is constant. Unless EFI has a fuel temperature sensor it cannot adjust for this and without a Lambda sensor to detect this it misfuels as a result.

[0007]

Overall I really have no problems with carbs and it's good that we can work on them in our home shop but there are more problems with carbs and more running condition issues

A modern 4 stroke MX bike has never really existed in this state of tune, the power level is just off the charts and when these engines were carb'do quite frankly they were very very hard to tune and sucked to start and they just changed from time to time, in a way they forced major carb developement be use they were so fussy, EFI made these bikes a lot better

Expense is an issue but we can't let this get in the way, manufacturers need to progress, can you imagine if they stopped, we wouldn't have liquid cooling or a descent ignition system or any reasonable suspension, bikes would be 350lbs

Heck we would be wearing hats instead of helmets and tires would suck and and and the list goes on

I thrive on and I need new and improved or I would quit the sports I love, it's not just trials bikes its boats and sleds and street bikes and ATV,s and so on

Bring on bigger better stronger faster and even bold new graphics

[nigel dabster]

#28, you say its not a question for me and I hope some owners answer it but I will make a few comments.

Ossa. I have first hand knowledge of one of these a 2012. The owner, a very experienced rider who has won on other bikes was never happy with the way it ran nor the starting difficulty. More than once he was without a bike for some time because the bike was away for remapping. The dog bones broke and the bike was exchanged for another make. In my area (Not far from Birks) Ossas should be common, they are very rare. Reliability and starting problems, high depreciation and distrust of EFI are reasons for this. There are not many 4Rts about (in my immediate area) but as far as I know none has broken down as a result of an EFI fault.

This is where you bend an argument to suit your point of view, which negates the whole thing.

Anecdotal evidence of one bike doesnt mean you know everything about the brand. Most would agree (birks himself I'm sure) that the reliability of the ossa was questionable in 2012 models, its much better now and a pal got all the way round the scott on one.

To take a leap and glibly say "distrust of fi" is based on not one shred of evidence at all.

Out of all the things that would put me off buying one this would be the last.

[steveo]

In regard to the question on FI components. I have had the first 3 280i Ossa's with all of them used exclusively for Trials, no fast trail riding. The first 2 had over 120 hours with no problems at all with the FI and the 2013 has only 100 hours and again not a problem in that department.

[andyrothers]

Isn't it as simple as "you pay your money you take your choice"

[baldilocks]

Thanks steveo.

So whatever issues people think may arise in reality FI seems reliable on a trials bike.

[hrmad]

4rts sound pretty reliable by accounts online, it will be interesting to see how ossa FI systems last 5 years down the line- but most people will probably buy a new bike by then I suppose. If Honda still made a 2 stroke I would be tempted to save for one, hehe.

What tech are they using on modern 2 stroke MX and enduro bikes these days? And is it applicable to trials?

[jon v8]

The simple fact is fuel injection is way better than carbs can ever be.The trouble is there has to be a compromise on development costs,price of parts and design life etc.In my work world of Land Rover products EFI transformed the Rover V8 engine and made it run properly.The current crop of Ford/Jag/LR v8's have engine management so accurate you could never imagine a carb being in the same universe.Power,driveability and emissions are all excellent,and its extremely reliable.

Trouble is with bikes is that they don't have the same R and D budgets,if they did and emissions laws were applied to bikes in the same way that cars are - we would have said goodbye to carbs long ago.

Most resistance to EFI is like anything else,a lack of understanding,once you learn how it works is actually very simple and easier to work with than carbs.This is because generally you can view live data to see what is actually going on.I wonder how long it will be before Honda use wideband oxygen sensors on their 4rt - that would take the whole thing on a large step...

[b40rt]

4rts sound pretty reliable by accounts online, it will be interesting to see how ossa FI systems last 5 years down the line- but most people will probably buy a new bike by then I suppose. If Honda still made a 2 stroke I would be tempted to save for one, hehe.

What tech are they using on modern 2 stroke MX and enduro bikes these days? And is it applicable to trials?

If FI is not reliable, your bike will have little or no residual value if the replacement parts are as expensive as being mentioned.

[tahoebrian5]

How about the apt smartcarb? Similar to a lectron, uses a single metering rod instead of multiple circuits like a conventional carb. I've got one on my ktm and its a bit smoother than the stock carb. Apt claims that it atomizes fuel better than FI which results in more power and better fuel economy, and better for the envirment. They are closed circuit so they don't leak, and they automatically adjust for changes in atmosphere and air filter, etc. I still find myself adjusting the needle occasionally. Nice thing is, there is an adjuster on top of the carb, so it only takes seconds to "rejet"

Anyone have them on their trials bike?

[0007]

Yamaha used Mikuni "Smartcarb" in 1996 on snowmobiles, there was a host of problems and repeated failures of the solenoids that controlled air flow through pilot and main circuits

And we had to rejet cuz they just didn't compensate properly

The next model had flatslides and I never heard of smart carb again after that

[tahoebrian5]

That must be a different product. The APT smartcarb is relatively new and has no affiliation with mikuni.

Here is a link

http://www.powerapt.com/index.php

The billet versions are spendy, but the cast versions are around $400 USD if I remember correctly.

Edited December 23, 2014 by tahoebrian5

[dadof2]

#36 I see you are picking holes again rather than making a positive contribution.

My experience of Ossa is not limited to just one bike, I just quoted this example because I knew it from new and regularly rode with and discussed it with the owner and knew some of its history after he disposed of it. I know of several other Ossaa that have had starting and running problems and mechanical reliability issues. I have also seen John Crinson win (although he fived my not too hard section) on one, but his success has not been sufficient to outweigh the perception of unreliability that has been created by other Ossas failures. The owner of the bike I gave as an example described it as a "heap of shyte". A bit harsh perhaps but it sums up his experience and frustration at the amount of down time the bike suffered.

Evidence of distrust of EFI. If I posted this my posts would be a mile longer than they are. I know of plenty of people who distrust EFI and are well fed up with the repair bills they get from it, these mistrusting people range from farmers, to car owners and motorcyclists. Try convincing a tractor owner who has just had to fork out £2500 for new injectors or a car owner that £550 for a single injector is reasonable and you will soon experience dislike and distrust of EFI.

http://www.pistonheads.com/gassing/topic.asp?h=0&t=625641&i=0

[dadof2]

A couple of old saying that spring to mind regarding carbs vs EFI

1) If it ain't broke don't fix it

2) Fools rush in where wise men fear to tread

Honda have done a very good job of miniaturising EFI and getting rid of the wiring harness, but these small EFI units are not integrated with the ignition ECU to the same extent as car systems. It effectively became compulsory to fit a Lambda sensor and use closed loop fuelling on cars from 1993. 2T EFI is not yet closed loop, ie. it is already at least 11 years out of date, and when riders of 4RTs dispense with the Lambda sensor they pretty well retard the fuelling to a pre 1993 situation.

Honda have vast experience of EFI and sell the systems in very large numbers meaning development and tooling costs can be spread thinly. European manufacturers of much lower production volume and less developed 2T EFI systems are likely to face significant difficulties and high unit costs.

Honda have some of the highest manufacturing quality standards in the world and for their off road bike supply decent manuals. Compare this with the usual output from the Europeans.

Long term back up may also be an issue. EOBD (which trials bikes don't even have yet) is not as universally compatible as it should be. I know of at least one series of vehicles where a scanner is not available and the manufacturer never sold the diagnostics kit, they just leased it (quite expensive) to franchised dealers. Once the volume of those vehicles being brought to franchised dealers for servicing / repair dropped the dealers no longer bothered to lease the diagnostics.

Unless there is some sort of rigidly enforced OBD protocol for bikes soon there are likely to be numerous serviceability issues in future.

Read the text below the video, the link may not take you to this, 3 injectors at $500 each?

A quote I came across "Old technology.? You are not paying attention. New 2 strokes are super quiet, super efficient, no smoke, and I get 2 nm per gallon. My old yami 2 strokes were great motors and lasted nearly twenty seasons, but the technology in the new etecs can't be denied"

Edited December 23, 2014 by dadof2

[jkmr1]

2012 TR280i. Hundreds of hours riding. Hot, wet, humid conditions. Starts first or second kick always. Runs perfectly always. Never had to replace any EFI component. I have the cables and software so diagnostics and remaping is no problem. Only thing I did to make it work was fit a small 12v flight battery.

2014 JTG 300. spent hours and Hundreds of $ upgrading to a Keihin to get the best performance out of it.

2015 JTG 300 Racing. Half dozen kicks to start from cool (Never really cold!) Starts first kick when hot. Runs perfect.