sportsawyer

To find ethanol free gas in the USA & Canada, see: http://pure-gas.org/

I use the Apico forged short levers. Reasonable price and don't snap easily like the cheaper cast levers.

See the manual available via the link that JimmyL provided. You can download the PDF manual for a 2016 300RR in English. Wiring diagram for the European street legal version (2ED) is on page 6-16 and the competition version (4ED) is on the next page. See the 4-pin connector on the latter (located near headstock) for where street legal sub-harness attaches to the main wiring harness for power.

The 300RR uses washers under the springs to get a little more preload and clamping force. If you want to see the location of the washers, there's a 300RR parts list on http://www.montesa4rt.nl/ and the washer is Reference # 20 and P.N. 22403-NN4-L60. Mitani sells Tomoyuki Ogawa springs which are advertised as "stronger", Banyeres sells them. Another option would be slightly softer springs and use all six. I can't suggest what would work. Like JimmyL said, the newer friction plates are better. I use those with dimpled steel plates and Dex VI ATF, this works very well for me.

The pre-2014 4RT crankcase is not directly vented. The only gas path out of the crankcase is through the reed valve into the stator / timing chain case. Once there, gas travels to the head via the timing chain opening and out the breather tube on the valve cover. So on the piston downstroke the crankcase vents. But on the piston upstroke, the reed valve closes and there is no venting. So as the piston moves up, it starts pulling a vacuum that resists the upstroke. The 2014 and later 4rt crankcase has a small orifice between the left crankcase half and stator / timing chain case in addition to the reed valve. I haven't had one apart yet, so I haven't seen if the orifice includes a ball check valve or if it's just a simple orifice that flows either way. It's on the 2014 and later parts diagram for the crankcase, Reference # 18, P.N. 90901-NN4-D00 with description ORIFICE #190. If it flows both ways, I'm sure it could be sized such that the downstroke would still build up enough pressure to open the reed valve. With this configuration, the downstroke is still vented through the reed valve and out the breather tube as above. Some venting may also go through the orifice and combine with the flow to the breather tube. But on the upstroke as the piston starts pulling vacuum, gas can be pulled back on the breather path, through the orifice, and relieve some of the vacuum and resistance on the piston upstroke. The cam and ECU changes are probably also contributing. How much effect each one has... I have no idea. I'm just bringing up the crankcase difference between the earlier and later engines and how I think that change could affect engine braking.

While the sump reed-valve may reduce engine braking, it isn't the change that may have additionally reduced engine braking in later models. I say that because the same reed valve has been in place since the very first 4RTs. I believe its primary purpose is for moving oil from the sump to the screen-filter / oil drain cavity that's exposed when the left side cover is removed. There are other changes in the 2014 and later bikes. One is an orifice in the left crankcase half that vents between the crankcase and left side cover (stator & timing chain). A similar orifice has been used for several years in the CRF250/450R, and went through some sizing changes over the years on those engines. It could be that this is helping reduce engine braking a little because it provides some venting on the upstroke to reduce vacuum -- vacuum created because positive pressure on the down-stroke opened the reed-valve. Another change is the cam, which has longer open-times for both the inlet and exhaust valves. This could reduce engine braking. See http://www.montesa4rt.nl/ (Tuning | HRC | Camshaft) for the difference between the new cam (HRC cam) and original cam profiles.

There's also a later "Setting Tool" (wiring & box) that uses a USB connector. 99techno, you may also want to check Banyeres as a source.

There's a test procedure for the fan relay on page 6-9 of the manual. The temperature sensor isn't an on/off switch, it's resistance changes continuously with the coolant temperature. It's not connected directly to the fan relay. The temperature reading goes to the ECU, and the ECU tells the fan relay when to turn on. The ECU also uses the coolant temperature reading for FI along with the other sensors. Manual page 6-5 says at room temperature, the temperature sensor resistance should be 2300 to 2600 ohms.

My 2014 came with a hardcopy owners manual, but it didn't include the parts list like my 2005. American Honda sent a CD later with a PDF parts manual.

Sorry, I misread your first post. If the ground wire & connection is good, the B/W is about all that remains. You might try removing the ECU connector and make sure everything is clean and dry. Maybe check the B/W wire connection to the connector pin. While the connector is off, can check continuity from the B/W pin to the kill switch B/W bullet connector. Same from G pins 14 & 30 to kill switch G bullet connector. It seems like the only other thing would be that somehow the shutdown procedure in the ECU became corrupted.

I haven't seen 2017 parts lists online. But http://www.montesa4rt.nl/ has web-based 2016 parts lists for both 4RT260 and 300RR, and Montesa France has PDFs for download. In the meantime (until 2017 manuals show up online, or you get a CD in the mail with a PDF parts list for your bike), if you understand how Honda part numbers work, you can probably guess 2017 parts that you know have been changed on the new models. For example, the brake pedal changed on the 2017 300RR. The 2016 PN is 46500-NN4-L60 where the "L" shows it's a new part in 2016 and the "60" is for the 300RR model. So I'd bet that the changed 2017 300RR pedal will have PN 46500-NN4-M60.

The engine stop switch on the 4RT is normally open, and closed when pressed. If I'm reading your post correctly, you've replaced the switch with a jumper wire. That's the same as having the switch pushed full-time, so the engine will not start or run. Remove the jumper wire -- just leave the switch connectors unconnected -- and see what happens.

Turn it in (CW) to closed, then open it 3 full turns (CCW). This should get you to a point where it'll start, but it may be a little high on the rpm, so you may have to close a little from there.

To check for a stuck-open injector, you could also just remove the tank / injector assembly from the bike (leaving fuel line and return line connected), position so fuel tank is normal (with some fuel in it) and injector is over something to catch fuel, and connect a battery to the fuel pump 2P black connector. For checking stuck injector, I don't believe you'd need to have the injector connected or pressure regulator vacuum line on. So it could be done away from the bike on a bench. It sounds like you may have already done something similar in the first post. If you know someone with the PGM/FI programming tool, it has some primitive diagnostics. Look in the manual chapter 6 for information. Good luck, hope you find the problem.

That's what I got from the text. I'd suspected they had separate maps for each plug, and apparently that's the case. So there can be a lot of control of the burn by changing how the plugs fire as a function of TP and RPM. This new works engine was first used in FIM competition in 2013 -- the first year of the new no-stop rule. Don't know if that had anything to do with it. Another change in that engine is cases that have clutch slave cylinder mounting on the left side. So the clutch configuration can be similar to a 315r, CRF250R/450R, Beta, Sherco, ... with pushrod through the main shaft. If you look back at WTC photos from 2013 on, Bou used the new clutch configuration for part of 2013 and then went back to the same clutch-cover actuation as stock bikes. Fujinami used the newer clutch longer, but has been back on the clutch-cover actuation for a while now. All competition photos I've seen of Busto -- when it could be determined -- show him using clutch-cover actuation. The interview had some vague wording about importance of clutch in trials. But didn't go into the use of left-side actuation and going back to clutch-cover actuation. If you look at current photos, you can see a simple plate covering the slave cylinder mounting location on the left side, and clutch hose / banjo bolt / etc. on the right side of the Repsol-Honda Team bikes.

Honda has some information about Bou's bike here: http://world.honda.com/WCT/2016/toni-bou-v10/machine/ The article shows the works TB/ECU unit and has some information on the dual spark-plug phased ignition.

The difference is the 4RT clutch is actuated by a slave cylinder in the clutch cover rather than rod coming through from the left side. So adding washers between the posts and clutch lifter plate 22361-NN4-000 (where they'd need to go in this configuration) moves the lifter plate out and pushes the slave piston further into the cylinder. So it'd depend on having enough back-cylinder for the slave piston, or putting more gaskets or a spacer under the clutch cover to get the slave back into its normal working range. Bottom line, it might be a little more involved to go that way vs. a clutch actuated from the other side.

The 300RR has a washer (P.N. 22403-NN4-L60) under each spring to get a little more preload than the smaller displacement 4RTs. So you might be able to get a small reduction in clutch pull by removing the washers. Which would be like flipping the hat washers on a Beta. I'd guess Honda put them in for a reason. So you might get a little clutch slip with the washers removed on the bigger engine. Don't know if you could find a clutch master cylinder with softer leverage ratio or smaller piston.

Did you check the fork tubes for any nicks? Local peaks around nicks can damage the seal. I've had a few, and took the high points off very carefully with a fine, flat whetstone.

I'm hoping Montesa is coming up with a 3E "Competition" version in addition to the ED version for 2017. It may be a lot easier to get that into the USA. Personally, I'd much rather have a 3E than an ED.

I looked at it a while back, and couldn't see the different transmission gears either. Also didn't see the shorter footpeg brackets, but they could be buried in there somewhere.

The 2005, 2007, 2009, 2012, 2014, and 2016 parts lists all show the same PN for this bearing -- 91071-NN1-000 BEARING, NEEDLE 15X21X12. They were also used in the 315R.

The ELF HTX740 is a very low viscosity gearbox oil.

I just measured new OEM and aftermarket dimpled plates, and got the same thing -- 1.4mm for OEM, 1.5mm for aftermarket dimpled. I've used aftermarket dimpled plates from Jitsie and Apico, both work the same and I'd guess they are sourced from the same manufacturer. I have the dimpled plate setup in 2 bikes, and both work perfectly. I'm also using the OEM friction plates (with newer version -B00 papers) and Dexron VI full-synthetic ATF. I think the hydraulic actuation would self adjust to the slight change in stack height. Did you check the clutch hub and basket for notching? Not sure, but if either is badly notched, the change in stack height might cause problems. Only other thing I could think of is assembly wasn't quite right when put together with the dimpled plates the first time. You're getting the dot-marks lined lined up, right? I've also heard the center-nut torque should be done to spec (I've always done it to manual spec), and I tighten the spring bolts with crisscross pattern in many steps -- moving the lifter plate in evenly and slowly. Good luck. I've been very happy with the setup I'm using... really couldn't ask for a better clutch.

Seems like the most likely location for transmission oil to get into the engine oil is the right (primary drive gear) side crank seal. See frame E-11 in the parts book, part reference number 31. Note there's a reed valve (reference number 12) at the crankcase bottom. And the reed valve opens to the stator / timing chain side when there's positive crankcase pressure (piston going down) to purge oil from the sump. So when the piston is going up, and the reed valve is closed, there's some vacuum in the crankcase. The vacuum could be pulling oil in past a bad right crank seal until the transmission oil level gets below the bottom of the seal. That might be about a 100ml drop.