"I'm basically asking for some honest replies to reassure me that these bikes are good, reliable and the company itself is stable."
By knowing your location we can refer you to actual owners and perhaps get a test ride on one. All trials bikes have some issues, some more prevalent in certain areas. Dry areas don't see much magneto issues, hot areas see lots of fan issues etc.
Some areas have brick and mortar trials shops some support is out the back of a van or trailer.
You are asking for our help we are asking for some basics to give the best support possible.
Did you set the Tiny Tach on 720 = 1 spark per 2 revolutions?
.5 spark per revolution I believe is the correct setting, but the unit only allows 720 degrees or 1 spark per 2 revolutions which one could argue is the same thing.
We don't know the programming related to the firing or the “wasted spark” characteristics of the Montesa FI.
I bought one of the Tiny Tach and set it on the 720 setting. The revs drop down when the fan kicks by about 150 RPM.
I was riding an event approximately 50 miles NE of Payson AZ in the Tonto National Forest area.
The bike was running great up until that event. May as well have been Everest as I could not breath LOL
I kept expecting to see a Sherpa (no, not a trials Sherpa bike) at the section with water and a oxygen bottle and offer to ride my bike to the next section for me LOL
I am not going to be drilling holes in my fender to let more air in. I have changed to a one step hotter plug, removed the back flame guard, cleaned out my air filter, re-checked my RPM to 1875. Re-route any and all breather hoses going into the air box.
I will be back riding normal altitudes (2000 > 3000 ft) this weekend so we will see how she rides. She ran great at those heights prior.
One other suggestion I received was to try running Race gas for high altitudes. What do you think? Do you think race gas at altitudes has the same effect on a FI bike as it would on a normal standard carb bike? Will running race gas harm the FI injectors. Cope, BR40t please chime in on this question.
“So that leaves” What....... Yer a*** hinging out the windea or what.
“You can fiddle with the air box” Eureka......... As stated all along I need more air flow/volume just as others have also stated by their air filter/ flame cage removal, air box/ crank case hose re routing, open up the fender air breather holes, recommendations. You started off by suggesting to change to a richer jet and then got all pissy when it got ignored.
In this FI case more air at or passing by the air sensors equals more fuel being injected in equaling a correct air fuel ratio and hopefully a
better running bike.
Still open to any others suggestions or experiences at high altitudes, high temps, little to no ambient air flow in wooded conditions with the FI Repsol.
Or necessary to stop ye bleathering on aboot brass jets. Auld reekie nippin year heid.
So what jet do you want me to change to fix the problem. Or any suggestions in how to re-program the FI to get more fuel even when there is very little air?
I checked my valve clearances at 2-3 hrs use on my 2014 and they were spot on. I assume they would be need checking again in about 40 hrs? Chatting with importer here in Australia he has not seen them out from factory... highly improbable to be out at this stage but not impossible.
The pipe out of the head is a crankcase scavenge/vent system AFAIK. So technically, dirty air (potentially oil misted air) gets drawn back into engine. Should not be an issue normally, as Honda engineers are pretty good! (wink) Can be an issue if rings/valve guides are worn excessively.
Mags
Mags
There are actually two breather tubes/hoses. One from up top (valve cover) and one from the top of the crankcases. The one from the top of the valves runs into a reservoir and then on to the air box. That one has already been removed from the air box and relocated. The other just hangs out pointing downwards.
If this was a stock venturi carb you would expect to see a blackened sooted plug in the issue I experienced on Sunday.
In this case (extreme case of high altitudes, high temps, stagnate air flow) of a FI system you would expect the opposite as in lean and white plug, why?
All fuel metering devices be it venturi or FI try to control the ratio of fuel to air. Not air to fuel.
In a stock venturi type carb we change jets to adjust fuel flow. The air coming in is set by the rider lifting the slide vie the cable and the size of the carb inlet and outlet and of course the size of the piston creating a vacuum. If the plug read too lean we would richen it up too rich lean it out vie the jetting.
On a FI system the sensors read air pressure air temperature and throttle position vie a sensor reading throttle opening this last one basically tells the engine management computer how fast the rider wants to go and how much air is going to be let in vie the throttle position. Once these readings take place the computer tells the injector how much fuel to squirt in to maintain a given fuel to air ratio.
For a standard carb and FI system There is a different fuel air ratio for each given RPM or throttle position or in a standard carb a different ratio for each jet or needle position.
Outside of re programming I have no control over the amount of fuel I can only control to a certain degree the quality and quantity of air being drawn in.
If this is true then as the air drops in quality and quantity then the engine management control will try to respond by cutting back the fuel accordingly to try and compensate for the lack of air, all while trying to maintain the correct fuel air ratio at each given throttle position.
There will come a point where at higher RPMs the correct draw for air will not be reached due to altitudes and extremely warm temperatures and stagnate ambient air flow so the FI management system will cut back the fuel accordingly, something has to give, my throttle position sensor is saying to the engine management unit the throttle is wide open therefore lots of air should be coming through yet the sensors that sense the air quality air temps and pressure is saying nope we don't sense that, turn the fuel down, yet the engine is still spinning wanting fuel and creating lots of vacuum pulses and in turn a lean condition at the plug tip hence why my plug is whitish.
One would expect to see a leaned out whitened plug in this scenario which I did.
The opposite is also true. That at sea level the FI system still tries to control fuel to air ratios. At sea level it will see lots of cool air coming in and will give out more fuel to the injectors as the ratio needs to be richened up as there is more air available.
Or in winter time it will sense cold dense air and provide more fuel to keep the ratios constant.
Hence why we richen jetting up for winter and/or use a choke.
Or maybe I am full of crap and too old to grasp FI
Glenn
Yes the system has lots of sensors monitoring the air quality, temps, pressure, throttle position, crank position etc. Look for the attached PDF in one of my above posts showing the sensor layout.
Tell your Scottish friend I am from Glasgow and live in the USA now. I can give you my cell number if you wish to give it to him.
Br40 with all due respect I don't think you understand the parameters and the non changeable variables we are working with here.
We don't need a lesson in carbs or lean vs rich. That knowledge is plentiful on this site.
The high altitudes and high heat are what we have to re-act to. The high high altitudes
mean less air, the high altitudes and high temps mean not only means less air but the air that is present is VERY hot.
Putting a richer jet in to cool it down if at all possible with a lack of air does nothing to help this problem.
Re programming the FI system to make it richer can only be done to a certain extent as the quality and quantity of air is still an issue.
The programmable ECM engine control management looks at all these variables and controls the fuel deliverable accordingly vie the algorithm. It can add more or less fuel accordingly but it cant control more or less air as this is fixed by the size of the inlet throttle body and the position of the butterfly valve controlled by the throttle tube.
If there is not enough air or cool to pull from then we have problem period.................
We are trying to figure out how to get more cool air or just more air period into the air box.
Going on about jets or jet theory is irrelevant. The ECU will adjust its fuel according to what it sees coming in i.e. concentrating on the mixture as you said.
Even if we could change to a richer jet you still need air flow at the correct ratios to make it all work correctly but if there is barely enough air to let the rider breath correctly let alone ask a FI system to work correctly then what?
You can see by the attached PDF file at the bottom that the idle screw (7) is in fact a not a hard mechanical butterfly throttle body stop but rather a air by pass orifice.
It affords an air adjustment from the filter side past the butter fly to the throttle body at idle.
If this is true you can then assume that the idle screw definitely only adjust the idle RPM which is necessary
for good starting amperage/voltage.
I am using a Jitsie filter currently.
The idle is sitting at 1875 RPM checked with a Snap On Automotive Digital RPM meter.
John suggested running a hotter plug i.e CR5EH-9. The bike comes standard with a CR6EH-9
I will follow the advice of running one step hotter plug (#5 instead of a #6) along with trying to get more air flow into the filter box.
JSR Hunt what do you mean by "It may also be worth removing the head breather pipe from the airbox just to get that little bit extra clean air into the system”.
Apart from that I guess it is all in the ECU and mapping as it looks at air density, temps, altitude etc and then goes through its algorithm accordingly supplying fuel.
I guess it was a perfect storm of high temps, stagnant air flow in the woods, high altitude, and dry dusty conditions.
This is a direct quote out of the 2014 Montesa manual
"Start Up Recommendations: If using your motorcycle at different heights, bear in mind that you must adjust the idle; otherwise you may have problems operating the vehicle”.
So they want you to adjust the idle at higher altitudes, partly due to starting and idling and off idle.
That coupled with my bad throttle and clutch control did not help.
The bike starts okay at sea level. It is also a 2014. Could the valves need adjusted already?
Here is my issue. I rode a trial Sunday and the bike kept stalling in the sections. I somewhat fixed that (how later).
Then on up hill climbs with several rocks to climb the bike would hesitate or get all boggy.
The bike was also hard to start sometimes.
Caveat to the above issues are the following conditions.
It was around 90F Altitude was over 8000ft No air movement as the trials was in a forested area. Dry and dusty. Dry air filter no oil on it.
I turned up the idle, that some what took care of the hard starting. Turing up the idle partially took care of the stalling in the sections.
The bogging down and sputtering continued on the bigger obstacles.
I am now down at approximately sea level today and the bike seems fine.
My hypothesis: The fuel injection just could not handle the high altitude coupled with the high temperatures no air flow and in a stagnant forest area. The air filter was somewhat clogged up but I could still see through it when held up to a light.
I need more air less fuel at the higher elevations, but how?
So now what? I intend to ride more of these higher altitude trials events and it will be hot dry and dusty with little to no air movement?
On a normal carb the idle adjustment only affects pure idle and just off the pilot jet.
The questions is: on the 2014 Repsol fuel injection system, does the idle screw still act like a standard carb idle screw or does it affect the other parts of the RPM range also. In other words does opening up the idle screw let more air in at more than just low idle type RPM’s?
I dont think it does but I want to get some more opinions on this!!!
If it only affects idle then how do I get more air in at the higher RPM’s?
It hard to advise as it is very hard to really see your technique due to how far away you placed the camera to the spot where the obstacle is. Can you please re-shoot with the camera closer and then we can really see what is going on?
Place the bike on a stand (not on the side stand). Take a close up picture of the bars from the side view. We want to get a idea of how you have the bar rotation set up relative to the ground/triple tree.
What gearing do you have, front and rear.
Tell us about you! Height, weight etc.
Do you have long skinny arms, short and stubby arms? Do you have long skinny legs or short stubby legs?
Not sure about else were. But my experience and some others I know is that the stock Montesa gas cap can and does disintegrate.
The internal base can separate from the outside cap making it useless.
Also ask Vince at V Mar about the extended rear brake pedal I had him make for me and my Respol riding buddy. The stock V MAR Montesa replacement rear brake pedal is shorter in length than the stock Montesa rear brake pedal which is good. However the foot rest is VERY narrow causing one’s foot to roll off of it during hard braking. I had him make me a wider foot rest on the rear pedal and it works great.
I also find the stock Montesa gas caps to leak as the seal under the cap gets broken as one twists it on and off repeatably.
The V Mar has a nice big thick O ring that seal gas cap to petrol tank.
Tell him Billy Traynor in Irvine advised you about getting the re-designed rear brake pedal.
Concerns
in JGAS (Formerly Jotagas)
Posted · Edited by billyt
"I'm basically asking for some honest replies to reassure me that these bikes are good, reliable and the company itself is stable."
By knowing your location we can refer you to actual owners and perhaps get a test ride on one. All trials bikes have some issues, some more prevalent in certain areas. Dry areas don't see much magneto issues, hot areas see lots of fan issues etc.
Some areas have brick and mortar trials shops some support is out the back of a van or trailer.
You are asking for our help we are asking for some basics to give the best support possible.