450 MXer Pitfalls?

[Cary]

Pretty much sounds like the same routine with my brothers 125. Does it cost much more than a 2 stroke for the piston and ring and to get it sorted by a shop? Liked to be able to do it myself but thats unlikely

Yes as there is the cam chain etc involved but for shop it's not a major as have tools/experence, so a simple job.

I haven't had one done by a shop but would only figure on 2-3 hours labour.

[Windy]

This is my first post, so I'll make it count.

Yes 4-strokes need more maintenance, they have more moving bits to wear. But if you change the oil every 500 miles, or after each race engine life is better than a 2-stroke (2-strokes have given me a very sensitive clutch hand ).

Yes Supermoto is hard on MX bikes, particularily the gearbox, as they invariably won't have a cush drive. Thrashing an MX bike around a supermoto track is no different to engine life than thrashing it around an MX track.

Re. piston life. If anybody is quoting times like "10 hours", then they are talking 'race' hours, and if the average race is only 15 minutes long that's 40 races at top level racing standards (or a whole season). At 'club' level you should get years.

Re. valve clearances. Get a Yamaha, or any other bucket and shim engine. That way you can check them as often as you want but you will rareley have to do anything. Buy a Husaberg, for example, and you do need to check them very, very often.

So change the oil (any good 10/40 will do), and there is no reason why a 4-stroke will be any less reliable than 2-stroke. The only thing to add is that when it goes bang the four-stroke will be more expensive to fix.

I have just completed my first season at supermoto on a seven year old bike and have only had to do oil/filter changes, and air filter cleaning. I will be having a peek at the valves, but I doubt if anything else will need attention other than swingarm bearings and fork seals (but that would be the same regardles of the bike).

But if you want to do the SM thing I would go WR because of the 5 gears, just get the YZ timing mod done and you are away.

Long post I know, but I hope it helps you to decide

[Coyote]

This is my first post, so I'll make it count.

Yes 4-strokes need more maintenance, they have more moving bits to wear. But if you change the oil every 500 miles, or after each race engine life is better than a 2-stroke (2-strokes have given me a very sensitive clutch hand ).

Yes Supermoto is hard on MX bikes, particularily the gearbox, as they invariably won't have a cush drive. Thrashing an MX bike around a supermoto track is no different to engine life than thrashing it around an MX track.

Re. piston life. If anybody is quoting times like "10 hours", then they are talking 'race' hours, and if the average race is only 15 minutes long that's 40 races at top level racing standards (or a whole season). At 'club' level you should get years.

Re. valve clearances. Get a Yamaha, or any other bucket and shim engine. That way you can check them as often as you want but you will rareley have to do anything. Buy a Husaberg, for example, and you do need to check them very, very often.

So change the oil (any good 10/40 will do), and there is no reason why a 4-stroke will be any less reliable than 2-stroke. The only thing to add is that when it goes bang the four-stroke will be more expensive to fix.

I have just completed my first season at supermoto on a seven year old bike and have only had to do oil/filter changes, and air filter cleaning. I will be having a peek at the valves, but I doubt if anything else will need attention other than swingarm bearings and fork seals (but that would be the same regardles of the bike).

But if you want to do the SM thing I would go WR because of the 5 gears, just get the YZ timing mod done and you are away.

Long post I know, but I hope it helps you to decide

Give that man some rep. Thanks for all that info. That's what I wanted to hear

I'm selling the CBR for sure, I know that now, but I'm more likely to get an RG at this stage. Got some info on motorcycle/scooter couriering from Texmo and was thinking of doing that over my school break to earn some money that could go toward a nice motard in the future. Also it'll give me some bike time on the RG if I choose to race it, which is likely. Also thinking of saving some money for a cheap van/ute to take myself up to Manfeild without relying on my Dad and the trailer, just something cheap on trademe

Also selling the CBR and buying a cheap RG will give my dad the money to get the trials bike he's wanted for a while

[Garvani]

Well thank god for your post Windy.. you guys had nearly completly put me off the idea of getting a bike..

Heres the deal, im new to all this, i want to get a reasonably new bike say a 2001, and was pretty much sold on a yz250f (possibly a wr250f??)until i started reading about all this damn maintence you need to perform on them, i don't plan on racing (well not for a quite a while anyways) just for firebreaking & some track practice. Can someone break down the maintence costs for me? as in taking it to a shop to get done etc.. (im pretty sure i can handle an oil change myself tho :-) How often is a rebuild really needed? far out i hope not to often at $4,000 a go.... And how much is a set of pistons & rings gonna set back a guy...
Im not that financial so thank god i didnt just go out headfirst and buy a bike like i was going to do then find out a couple weeks later what i was in for. So yeah if someone could write me up a cost summary (along with the recommended hourily usage they should be performed at) cos at a guess i would think i would be doing at least 8+ hrs a weekend fanging around the local firebreaks etc...
Anyways hope i don't sound like a complete tool.

[Eurodave]

Heres a pic of the latest progress on my Honda 450 street tracker
Ive nearly finished the paintjob & my home built exhaust pipes are going in to be hi temp powder coated black very soon
Also Ive been doing a lot of polishing of all the alloy bits, dirty ,time consuming work but theyve come up a treat!
Ive made a pair of what seem to be called 'beauty plates' out of alloy,to hide the gobby fillets & Hondas pidgeon shit welding around the swingarm mount.
The chassis punches have been exercised too, check out the holy chainguard
Next up is a total strip & frame sandblast/repaint in 2K

[Badcat]

that looks sweet dave!!!!
the seat you made me is away being painted as we speak - will post pics in my XT500 street tracker thread when i have them.

excellent work!

ken

[Eurodave]

that looks sweet dave!!!!
the seat you made me is away being painted as we speak - will post pics in my XT500 street tracker thread when i have them.

excellent work!

ken

Cheers bro! Cant wait to see what youve been up to!!

[clint640]

They are still very reliable when motard raced and are a strong motor.
Sorry if I gave the wrong message there.
But any motor that lives at the high end of their rev range, pays a price in longevity.
And from what I have read more and more guys in Europe are now starting to using the RFS motors.

Rik

I wouldn't get stressed about thrashing an LC4, They are probably the most suitable dirtbike engine for sustained high speed. The current LC4 motors are the product of the 10+ years of development that has kept KTM winning Dakar on them every year, they are made to be held WFO all day.

That street tracker is sweet Dave!

Cheers
Clint