Off-season maintanance on CRF450X and KTM 300 XC-W

I have become my BIL's mechanic, which I don't mind as he provides the land for us to ride on, the least I can do is help repair/maintain/fix his stuff.

I had his 2008 KTM 300 XC-W apart as the bike would not idle. The root of that problem was the fuel line which had hardened and crystallized from the inside and was sending the small, plastic crystals all through the carburetor and clogging the pilot jet as well as the needle/seat interface. Once I had taken the tank off, cleaned it, the petcock and its screen, replaced the fuel line and cleaned the carburetor, the bike ran perfectly. Started, idled and ran like it should. He got a deal on the bike as it only has 16.6 hours and 300+ miles on it.

The 2008 CRF 450X is another story. I finally got the fuel tank off and it was full of sediment, dirt and gunk. Between the petcock/fuel inlet screen disintegrating and sending all the plastic crystals and bits of the screen's framing into the fuel tank, the petcock and the carburetor, I had to take the tank off and wash it out with Totally Awesome and water, flushed out all the petcocks as the tank is a larger Acerbis tank, and sent the carburetor out to be cleaned and rebuilt as the FCR carburetor is above my skill set and there are too many diaphragms, seals, o-rings and parts to check from wear that the cost of having a professional do it is worth it.

I have also changed both oils and the engine filter and cleaned the air filter.

I now need to wait for the new fuel inlet screen, a new NGK spark plug and the carburetor to come back and install it so all I'll need to do once I get all that stuff installed the only thing left will be to wheel the snowbike outside and clean out the airbox.

I'm glad I'm getting all this done now when the time to ride is not pressing and I can let things dry, wait for parts to arrive, and be able to do the work when it is nice out and not be in a rush for anything.

Meanwhile my 2017 Beta 500 RR-S is perfect, and is ridden back and forth to work every day there is no rain, and with the Rekluse Radius CX, is ridden off-road every chance we've been getting and this upcoming week is another chance for us to camp and ride.

coryf89 said:

water pump seal gone bad on the crf yet? (leaking from weep hole below water pump)


valve clearances and oil filter and thats about it on those hogs!

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No, no water pump seal, yet.

I know next to nothing about the bike other than how it runs and most of this past winter it has run like crap but that should all change with the fuel system having been cleaned and the carburetor being cleaned by FCR.com-a pro that should have it cleaned and rebuilt to be like new.

The bike had hardly been used when my BIL got it last winter. The KTM had 300 miles and 16.6 hours on it and I suspect that the 450 would have about the same miles as the engine looks almost new from the outside. My bike, being only a year and 1/2 old looks like it is 30 years old compared to the two bikes he got. I think that the two guys got the two bikes, rode around a field/farm for a bit and that was about the extent of their riding. I don't even think the bikes ever went through so much as a mud puddle as after 10 years, they are still clean and have never had any cleaning product sprayed on them, ever.

Misha Subo said:

We have two of the 300 XCWs - 2008s. They are the perfect bike for our purposes but there's a few minor glitches that needed sorting over the years.


1. Clutch side gasket should be updated to the thicker aluminium/rubber type found on later models ~ 2012-13..up. The original paper gasket blows at the water pump juncture and causes coolant to cross contaminate trans oil or vice versa. This causes poor cooling etc.

2. Electric starter motor should be replaced from 350 watt to the stronger, later model 410 watt unit. Huge difference in starting torque but make sure the thrust washers on the idler gear are shimmed to make the teeth fully engage on the starter pinion gear otherwise the teeth will wear out. Got a good cheap 410 watt ebay starter a month ago for ~ $120.

3. Jetting is really smoothend out by switchng to the Suzuki needle NECJ On the third clip down from top. See this thread of jetting recommendations which is for the later models but also works well with the 2008.

http://www.offroadontario.ca/forum/viewtopic.php?f=2&t=1430

Other than that, ours are bone stock 300s..one with EE and the other with a FMF spark arrestor. Going to buy a third 300 (don't tell the wife) for the second son who is now tall enough to ride my 300 in the dirt, we need three snow bikes and I'll probably get another Camso conversion. Camso/300 XCW is the perfect combination for our terrain = dense trees in the Algonquin Park area.

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I knew you had the 300 XC-W but did not know or remember that you happened to also have 2008's, the same year as the bike my BIL has and that I had just finished working on. It is an awesome trail bike.

I love the electric starter and now that I had cleaned the carburetor, the bike starts right up and idles perfectly. New air filter, changed the gearbox oil. Flushed and bled the clutch and brake-everything but the fork fluid and rear shock got replaced.

My BIL is planning on getting the Camso 129 kit for the bike and I'll be the one to install it this upcoming fall.

Misha Subo said:

Ben, your stock starter motor will work fine but I found to keep things loose (tight) by making sure your pinion-idler gear clearance is tight and everything lubed. Not necessary to do the Slaven's wet mod as long as the crank gear is greased and you clean that stator compartment out often - especially after a really wet ride with river crossings or water outs.


If you've got a nearly new 2008, I'd buy it off you in a heartbeat. I need the third one for my middle son, now about to join us on the snow bike trails this winter. Lucky you (BIL), they're such a simple, light, high performer. If you hear of another nearly new one PM me ASAP.

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Thanks for all the most helpful tips.

My BIL is planning on having me install the Camso kit this fall and for now, the bike is ridden lightly around his hayfield and dirt-road trails he had made on his mountain so it sure is not demanding terrain by any stretch.

He got each bike for $3,000 and I thought they were great deals other than the fuel system cleanouts I've had to do and which were not that bad. I had taken the carburetor on and off the KTM five times in an afternoon as I had kept adjusting the float height incorrectly. Once I finally got it right, things went well. That, and after I had replaced the fuel line-which was the original cause of all the carburetor issues.

I'll agree. The bike is incredible. It is light, and sits up really, really high, and the 300cc power has been awesome on the wide open hayfield perimeter.

If, somehow, another KTM 300 comes up, I will surely let you know. A couple of guys got the bikes new back in 2008, hardly rode them, then had them sit for all this time as the carburetors were really bad and between the fuel filter on the Honda crystallizing and the fuel line on the KTM crystallizing, they have held up incredibly well after 10 years.

I only hope that nothing goes wrong with either bike for a while as as much as I don't mind wrenching on them, I'd rather just ride than repair.