lotus54

I’ve found I need to adjust and reset the TPS about every 100 hours to keep it in top running form.

Lots are parts are ‘standard’ trials stuff- but certainly some stuff will get hard to find. Setting injection, checking and trouble (not really many ‘codes’) is easy (like mentioned, software and now cables are readily avlailiable). I have both and find (at least mine) likes to have the TPS reset about every 100 hours. I have almost 400 hours on my Explorer (also have a low hour factory 300) and is my favorite bike. But I want to be able to keep riding it so I bought a Beta 4T I can ride also and put less hours on the OSSA. The Beta is actually very similar to ride as the OSSA, nice smooth engine, weight about the same as the Explorer (much more than the factory). OSSA might have a bit better balance, but I’m just an intermediate trials rider (although I’ve been riding 50 years) and perhaps have no clue what I’m talking about. I would suggest a 2014 or newer, some big improvements were made. Still claims by the owner to try and start production again, but at this point I doubt it. Unless someone comes along and just starts it up with loads of money to do it right. Probably would need to be a big company like KTM that wants to build trials bikes and doesn’t. Seems unlikely to me. There is certainly a LOT of things it has I like more than any other current bike out there. The air filter location is one (way up high by the steering stem- stays really clean and doesn’t fill with water), radiator location (stays clean of mud etc and very protected), exhaust (tucked out of the way from damage), cassette gearbox (service is really easy if required), FI into the crankcase/transfer port (better fuel ecomomy and runs super clean) oh well. Lots of great bikes out there.

I've mentioned it before- but I've made a mod that make the OSSA very easy to start. A small LiPo battery that is only triggered when you hold down a 'kill button' style switch. they 'wakes up' the ECU and also runs the fuel pump. really makes a difference.

PM me with your email and I’ll set you up. mark

They look great! I like the new fuel venting setup. After the ‘claims’ by the advertising people, is there really any difference in engine braking on the 4T? Mark

After warm up, my 4T will start just find in gear with the clutch pulled in (all the way). It does not drag at all when all the way in. Normally I use one finger on the clutch and can’t pull it quite all the way in (hits my other fingers, even when slide in as far as possible), but no issue when riding at all like that. It will even start ok that way, but seems better all the way to the bar. For me, it starts really well- as long as I don’t kick it hard or fast. A gentle prod and it fires right up. I usually stand beside it, since that discourages a fast kick. mark

I have Billy’s old 300T. I use the same oil he used- the only time I have any issue at all is when initial cold start. Unless I let it idle and warm up quite some time- the clutch is sometimes ‘stuck’ and I have to ride with it pulled in and brakes on a bit to unstick it. I attribute it to the much colder weather than what he has- a lighter oil could solve it, but it works so well the rest of the time I just keep using the same stuff. It only does it after parked overnight or longer. Not a big deal to me. Mark

I’ve used special fiberglass brushes to clean the pins. If you had the factory cable- using the software you can activate the fan. That will show if the rest of the wiring is good or not. Then read the temperature. These will overheat pretty darn quickly with no fan, even with everything else in good working order. At least in my experience. Darn minimal airflow without it. Mark

When I had a small amount come out of the ‘drip hole’ I looked into replacing the water pump. (The drip has not happened again, so I have not replaced it yet). the manual says to replace it at some 60 hours, but I assume that is under extreme competition use and I doubt any ‘normal’ user does maintainence at those recommended intervals. I believe the best way is to remove the radiator and side supports, remove skid plate and all but the rear engine mount, remove exhaust. Loosen carb jubilee clamp and tilt the engine down. Then you can remove the top head cover and have access to the gear that drive the water pump. Do you have the service manual? mark

The OKO I fitted to my Explorer from Mid-Atlantic trials worked great.

LIke mentioned, I find mine starts much better with a very mild, slow kick. If I kick it like my OSSAs then it doen’t Like to start. I do find it is better with the hot start, not throttle, slow kick. If that doesn’t work, full throttle and a couple of hard kicks seems to do the job. Mostly if I have any issue it is due to kicking to hard. (So it seems to me anyway). Note I have a 16 factory model, the ‘high low’ power switch has been removed, so no idea if it does anything. I was told it doesn’t do much until high rpm. Mark

Yes, a good point. I try to clean everything pretty well after every ride. But I’ll give extra care., It has been quite muddy lately and the routes (I hesitate to call them trails) go though some swampy areas that get pretty mucky. mark

I’d suggest the easy things first. 1. Choke off 2. Air box doesn’t have a rag or something left in it 3. Replace sparking plug (perhaps the easiest?) It could be just a bad electrical connection, or poor earth connection on the coil.

Any part numbers would be very appreciated.

I had found the FI very, very reliable with quite minimal maintenance required. I like it. Software access was easy (of course now that OSSA is not in business, finding the interface now is difficult, but setup was super easy) But I certainly understand those not wanting to get into the FI world. The CV carb on my 300 4T works pretty well, but I wonder how it would be with FI similar to the Montesa (another bike I seriously looked into buying). just my thoughts- what do I know?

I have a 2016 Evo 300 4T It has a Grimeca caliper. Anyway, what it the consensus for the best brake pad for mud. It has some Galfer in there now, I can’t read the number. Looks physically the same as the SRS 802. Anyone have their favorite for mud? (Knowing the number for the rear would be handy also, just looking at the front at the moment) Mark

The OSSA injector goes directly into the crankcase- right at the rear transfer port. Not really that much different Than the KTM (only one injector of course), it is NOT throttle body injection. I do not know how the Vertigo is setup.

I didn’t see anyone mention this (sorry if I missed it). Make sure there it play between the lever ‘rod’ and the piston in the master cylinder. If the adjustment is too tight, the piston cannot come all the way back and it will do as you describe. Also check the adjustment that controls how far OUT the lever sits- if it is too far toward the handlebar it will do the same thing.

Also make sure your HotStart valve is not open. That will make it run lean with pops etc. Although not the rest of it.

Make absolutely certain the brake rod has clearance to the master cylinder piston. AND that the piston is coming all the way back down. Mine had that haywire ‘sideways lid’ on the master. So I need to either bleed from the back and open the screw- or use a syringe to bleed from the front. mark

For the front you can still run Tubliss. I find it works very well (I’ve gotten pinch flats with the stock tube). If your rear is a tubeless rim, then bring some plugs and a small pump. If a non-tubeless rim, then run Tubliss (I do on my OSSA Explorer, works fabulous). mark

PM me your email address. mark

I’ve been using Motorex 2T full synth. I started using it with my KTM 300 when new and it always seemed to work well so kept with it. I have a mixing container that shows very lean mixtures, so I just measure out the appropriate amount and put it into a 5 gallon container before putting in the fuel. The rush of from the pump mixes is really well. Plus I have it a few shakes after and before every fill. Lewisport told me to run 100:1 in the explorer, so that is what I have done. I’ll bet I could run less with no problems, it did have some carbon build up on top of the piston after almost 400 hours. But since everything looks so good I’ll likely stay at around 100:1. I do run around 110:1 in my Factory 300 OSSA- but I do more road connections with the Explorer (it is plated). I think the mixing container I have is from the boat section of the local ‘has everything’ store. Mark

I didn’t take it as an attack at all. I figured you were just clarifying. Glad to have the discussion. Mark

You are certainly correct, and I’m sure those work fine. That’s why I said ‘personally’. I make that choice for a few reasons, 1. The dealer (who would do warrarnty claims when applicable) told me specifically to use it. 2. I like the extra protection of a full synthetic. 3. It has worked well (so far) and see no reason to change. 4. I ride in cold weather often and I like the multi-weight capabilities (perhaps doesn’t matter) I’m not saying I’m right, just what I do. (I run full synthetic in my Beta 4T, Ducati and AJP, Car and Van also) mark