I'm using it on a dirt bike with the Tubliss system and it has held air for several days. The X11 on my Monty is still working good. The reason for the new D803GP is the D803 on my XR began leaking air thru the sidewalls from me running it too many miles at very low pressure. Based on the tire size I expected a low profile tire but ended up with one that is taller than a D803.
I just purchased a new Dunlop D803GP tire (120/100R18) to replace a D803 (4.00R18). I expected a low profile tire but what I got seems to be a higher profile tire than the 4.00R18. It appears narrower and the loaded rolling circumference at 5psi is greater than the 4.00R18 at 10psi. The tire is made in Japan by Sumitomo Rubber Industries Ltd. So I'm now concerned that it may not have better traction.
Hopefully not slipping. I've two clutches damage by using the wrong oil and had to replace the frictions.
I have a CR250R clutch pack in my 315R with dimpled steels and it is IMO a fantastic clutch, I've used the ELF HTX740 oil but switched to Valvoline Dextron VI ATF (synthetic) because the Elf is difficult to find and expensive in my area.
Update on the setup I'm using: Dimpled steel plate set (available from Apico or Jitsie retailers like BVM Moto or Splat Shop) and the OEM friction plates -- 2 each 22201-KY2-000 cork and 4 each 22201-NN4-B00 new type paper -- with Valvoline Dexron VI full synthetic ATF.
I first installed the above in my 2005 4RT in May, and it worked so well I changed my 2014 4RT260 to this setup when I ran out of ELF HTX-740 later in May. I was mainly driven by the fact that HTX-740 had become unavailable in North America and only thicker oils were available. But the above dimpled-steel setup worked better for me all-around -- smoother and longer engagement, no drag, no stick after sitting a few weeks or more, easier shifting, easy to find neutral, much less expensive for oil changes, and oil that's readily available from local auto parts stores.
To give an example of the elimination of drag and stick, as a test I recently started my 2005 4RT after having it sit unused for a month, cold andin first gear, on the 2nd kick. It didn't walk away with clutch stick or drag, just sat there idling. After a little time, with the bike still stationary, I shifted it into neutral with ease.
Very similar to my 315R experience, although I'm running all cork frictions; results are the best clutch action of any bike I've owned.
Two breather hoses go into those two holes on the left spar. I don't have my manual with me and it was a few years back but if I remember correctly it is the alternator and tranny vent hoses.
For a starting place on the Showa forks turn the clickers full out (CCW). Also a PO may have put the wrong oil in the forks, or too much. The oil for the right leg should be cartridge fork oil, a very thin oil. Showa SS05 or Honda SS05 fork fluid or similar. No cartridge in the left leg so the oil just lubes the bushings. The level in both legs determines the resistance to bottoming, standard level is 39mm from the top with the fork fully compressed.
Good discussion but I would add that at least here is the USA most modern car oils have anti fricion additives that can cause clutch slippage.and#160; Been there done that with Mobil 1 oils in my XR.
and#160;
ATF oils are wet clutch gear oils, which is what our 315Rs have.
and#160;
Besides all of the comments about cork vs paper friction plates and flat vs dimpered steels a dimpered steel has less drag, except my CRF250X has no drag with smooth steels. So YMMV.
and#160;
Synthetic ATFs have doubled or tripled the life of auto trannies for cars and trucks.
and#160;
Thin oils provide less drag and faster hookup, thicker oils more drag and slower hookup.
Oil viscosties are available at each oil mfg web site.
and#160;
All of which is why I run the Elf oil or Valvoline Dextron VI in my Monty.
and#160;
The 315R and 4RT clutches are based on the CR250R clutch, as is the CRF450F clutch.
On edit: my 315 has a CR250 clutch pack. A friend has an 05 4RT and it has the original plates and terribly grabby clutch with lots of judder using the ELF oil.
Stock jetting for my 04 is 35 pilot, and my mixture screw is out 2 1/2 turns so I'm thinking of going up to a 38 so the mixture screw will be in a more effective range.
Now there is a paradox! If they change it to Repsol (although in my 2014 manual it does say to use Repsol for the engine oil) we have no Repsol in Australia (that I've seen) so I'd be in the same situation like those that can't get Elf for gearbox… I couldn't get Repsol for gearbox, so i would use Elf!
As for the Elf and its friction additives and not being used in immersed clutches… if the additives allow slip maybe that what Montesa wants??? Doesn't slip on full clutch engagement but may slip slightly on take-up giving more progression on clutch take-up??? Just a thought?
Mags
Good point
My experience has been:
Modern car crankcase lube oils are risky to use in a wet clutch because anti friction additives can cause clutch slippage. But JASO-MA oils ar OK. ATF oils are gear oils for wet clutches.
Montesa recommends Elf HTX740, which is a very thin synthetic gear oil. Elf cautions to not use this oil in a wet clutch. EBC and others recommend not using synthetic oils in wet clutches. Go figure!!
Dextron ATF provides much smoother clutch engagement than "F" ATF.
Synthetic ATFs are much thinner at typical ambient temps than Dino based ATFs (see chart below).
Thicker oils cause more drag, thinner less drag and faster hookup.
Cork friction discs provide the smoothest engagement, paper the grabbiest. EBC claims smooth engagement with their sintered cork and Carbon Fiber frictions.
CR250 frictions provide better clutch action for 315Rs and 4RTs. Probably because they are all cork compared to Montesa using a mix of cork and paper plates/
I tried a Valvoline synthetic Dextron VI ATF in my 315R with good results. A little more drag when cold, slightly longer range of engagement, and smoother lockup. But how much was new oil versus old oil, or different brand? The increase in drag was fixed with a bit of adjustment at the lever.
I have also used Mobil 1 with a wet clutch with slippage problems. But Shell Rotella T and T6 provide good clutch action, but are thicker than the syn ATF.
If my memory serves me right, ELF HTX 740 has been the recommended gearbox oil by Montesa Honda for years, both for the 4RT and the 315 Cotas. Always used it, bought from BVM, but now I'm stuck as to where to get it from now.
So maybe I will have to consider an alternative.
But the HTX is difficult to find at my location so I did some research: The HTX is a very thin synthetic gear oil, Elfs spec sheet says the viscosity is 21cST@40C.
The closest I found was Valvoline Dexron VI synthetic ATF at 29.5cST@40C. So I tried that and liked the results. As a side other gear oils ranged from 35 to over 100cST@40C.
ATF is gear oil for wet clutches.
The Japenese bike makers have a spec for wet clutch use; JASO-MA. So any oil that mets that spec is OK for wet clutches, and that includes some engine oils.
But engine oils are thicker than HTX and thin oils have much faster clutch hookup and less drag compared to thicker oils.
The bearings are standard metric tapered roller bearings but with a 1mm larger ID.
The standard bearing number would be 32005/26, the /26 indicating a larger ID. The inner is probably not available from a bearing supplier.
The generic Honda part number is 91015-425-832, available from any Honda dealer. (used on a ton of off road Hondas from the early 80s to the late 90s).
on edit: The standard metric tapered roller bearing is 32005, the 05 indicating the ID. Metric bearing IDs are coded in the last two digits; 00=10mm, 01=12mm, 02=15mm, 03=17mm, 04 and up is times 5. Honda's version is is equivelent to a 32005/26 number, the /26 indicating a deviation from the standard. So you can buy the outers from a bearing shop but probably not the inner.
My ridding buddy has a 4RT and his fan runs a lot, but not really any more than the fan on my 315R. I let the 315 warm up until the fan comes on, that is my indicator that it is warm enough to ride.
My riding buddy has a 4RT and he often had starting problems that seemed unsolable so we started do some tests: We found that too fast a kick and it would not start but a firm slower kick would alway start the bike.
We suspect it has something to do with the rpm theshold that the ECU uses to determine starting mode vs running mode.
The starting mode also includes shutting power off to the cooling fan so more power is available for the fuel pump.
I've been using Valvoline synthetic Dextron VI ATF for several years and I prefer the clutch action over the ELF oil, very smooth and no drag. If you want sharper hook up use a non Dextron ATF.
The Valvoline Dextron VI oil has viscosity very close to the ELF oil so no clutch drag. other ATF are thicker.
I bought a PWK two years ago for my 04, but have been procrastinating installing it because it is a 28mm and I was concerned that I might lose low end throttle response.
Another problem is adapting the larger PWK inlet bell to the Monty air boot so I'm curious about your installation. Can you post pictures of your installation?
I encountered a simialr problem in finding the ELF oil for my 315R so I did some research and as others posted the ELF is a very thin synthetic gear oil; not recomended by ELF for wet clutches but recommended by Montesa. Go figure!
My 315R manuals recommends Elf HTX 740 but it is hard to obtain in my location. It is a very thin synthetic gear oil and I substituted Valvoline synthetic Dextron VI ATF, the clutch action is smoother which I like. Depending on how you like your clutch action a syn ATF, either Dextron type or standard type, would be two good options.
I posted the following in another thread on Monty clutches, although it is for a 315R the plates in the 4RT are the same size:
Besides the dimple disc, that Montesa finally switched to, oil has a big effect on clutch operation. Montesa specs a very thin Elf HTX740 synthetic gear oil, but it is expensive, and for me difficult to locate. My research. Thick oil slow hookup and increases drag Thin oil faster hookup and less drag. Regular ATF or Ford type vs Dextron type; Dextron has smoother lock up, regular ATF quicker lock up.
Thick and thin above refers to the oil's viscosity at 40C.
Gear Oils................................ @40oC........... @100oC GRO Gear Extreme 75W*......... 20.............. 5.2 Elf HTX740.syn........................ 21.4............. 7 Valvoline Dextron VI ATF syn.. 29.5........... 6.0 Motul ATF VI*..........................30,5...........6.10 Mobile 1 Dextron VI…………. 29.5…..…. 5.3 Royal Purple Max ATF........... 35.0............. 7.5 Valvoline +4........................... 34.13.......... 7.55 Allison Transynd syn ATF ..... 53.9............ 9.75 Elf HTX735.............................114............17.8 Amsoil 75W-90 syn**……….. 130……. 15.6 Amsoil 80W-140 syn**…….... 256……. 26.4 Silkolene Medium 85W-90... 150-340..... 15 Silkolene Light 75W-80......... 100-180..... 15 Silkolene Comp 80W-90........ 100-145.... 15 Silkolene Pro SRG 75............ 100-180..... 11 * info from Trials Central posts. ** Hypoid gear oil - do not use in a wet clutch
I have CR250 plates and discs (dimpled) in my 315R and switched to Valvoline Dextron VI ATF syn and have the best clutch action of any bike I have owned, and much smoother clutch action than with the Elf oil.
My friend's '05 4RT clutch, with OEM plates, is very grabby with lots of chatter while slipping. Apico sells the same clutch kit for both bikes. He has tried different plates and it still chatters, I think he should try a different oil.
New Dunlop D803GP Tire
in General Trials Talk
Posted
I'm using it on a dirt bike with the Tubliss system and it has held air for several days. The X11 on my Monty is still working good. The reason for the new D803GP is the D803 on my XR began leaking air thru the sidewalls from me running it too many miles at very low pressure. Based on the tire size I expected a low profile tire but ended up with one that is taller than a D803.