chuck4788

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 purchased mine from Rocky Mtn, included free shipping.

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. Anyone have some experience with this tire?

I have two friends with earlier 4RTs and they have not had any oil migration issues. The CRF versions of these engines are known for shaft seal failures that allow oil to migrate between engine/tranny.

Check your reed valves.

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.

Modifications are needed, biggest issue is the air boot is too small for the PWK. You can use Beta jetting for a starting point. Couple of threads in this Forum.

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.

Yes 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. The Owner's Manual covers all of the above.

Suggest this site for info on JASO certified wet clutch oils. http://www.oilspecifications.org/articles/JASO_MA_JASO_MB.php

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.

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.

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.

ATF is gear oil for wet clutches. 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.

Thanks I can machine one of those in aluminum.

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! Here is the thread http://www.trialscentral.com/forums/topic/44648-315r-clutch-oil-and-baad-drag/ Go to post #15 for the latest list of possible oils. You will see the Gro 75W as thinner than the ELF.

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.

The Montesa VIN PDF in post #7 also shows digit 9 as the check sum digit.

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: 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.