4-stroke mainenance

what is the weekly, monthly, and yearly maintenance of a racing fourstroke. (and i mean if i buy new, and want to keep it race condition because i competitively race) please dont give me reason to buy a two stroke, or why 4 strokes suck. just the maintenance i will thank who ever gives me good information. thank you for reading! :thumbsup:

Depends.

Some go nutz, some service as needed. I suggest you D/L a Yamaha manual and read what Yamaha recs for starters to get an idea.

http://www.yamaha-motor.eu/eu/services/owner-manuals/index.aspx

I have to assume you are just getting into to it and therefore you would be more on the service as needed end. That means a new piston and rings every 100~150 hours, valves every 300, oil change every 10 hours. Compare this to the manual. Pros do rings every day of riding in some cases.

want to keep it race condition because i competitively race
if ur a want a pro level motor basically have 5-6 that you contently rotate around sending them off to get rebuilt by a mechanic costing 1000+.

and i dont believe you are a "competitive" racer if you have absolutely no clue how to maintain your bike. Get out of your trailer and help who ever is maintaining your bike.

i usually do oil every 3-5 hours because oil is cheap and engines are not. piston rings should be done every 50 hours or so depending on how hard you ride, and a piston at every 100-150 hours-as William1 said.

on my 250f I check valves every 10-15 hours, piston, rings and cam chain at 60 hours, oil change at 5 hours (non synthetic) or 10 hours (synthetic) with the oil filter changed every other oil change

and i dont believe you are a "competitive" racer if you have absolutely no clue how to maintain your bike. Get out of your trailer and help who ever is maintaining your bike.

That's a little too quick to judgement. Maybe he was a 2-stroke rider who just switched to thumpers, I know it was a huge transition for me. Or maybe he is a cross-over rider who rides off-road and motocross and just realized he is more competitive in motocross. There's a numerous amount of factors to consider before being so judgemental.

Personally, I'm not a 4-stroke guy, I'm probably about to sell mine, but I wouldn't be so quick to judge autoxpilotxoff about not being totally sure of the maintanence of a 4-stroke, he may be looking at what other people do, espicially considering the technology of the new 4-strokes.

Maybe he was a 2-stroke rider who just switched to thumpers
and didnt learn anything about 4 strokes in the precess. Sorry man in not trying to insult you but common its a very cocky first post.

If you want 90% reliability then change oil every know and then and if it makes a bad noise then take it to someone who knows better.

If you want 99.5% reliability then buy at least two bikes and have a dedicated mechanic.

and didnt learn anything about 4 strokes in the precess. Sorry man in not trying to insult you but common its a very cocky first post.

How's it cocky? Because he said 'competitive'?

You should give him a break. For whatever reason he wants to know the rough maintenance schedule for a 4 stroke that's being raced in a non-newbie class.

I have to assume you are just getting into to it and therefore you would be more on the service as needed end. That means a new piston and rings every 100~150 hours, valves every 300, oil change every 10 hours. Compare this to the manual. Pros do rings every day of riding in some cases.

Are you implying my schedule of changing oil every 1000 miles or so and putting in new stainless valves and a piston at 20,000 miles might have pushed it some on my 400exc? I'll admit it ran a tad better after doing so.

I still have it as my Colorado mountains bike with even more miles and it's been flawless. :thumbsup:

"and i dont believe you are a "competitive" racer if you have absolutely no clue how to maintain your bike. Get out of your trailer and help who ever is maintaining your bike."

I've raced supermini for three years, won a supermini championship for the track where i ride, and have won 2 schoolboy races on my kx100. ive gone too two fca mx camps (the ones with Pro's teaching it? yea) so im definitely not a newbie, and having had my kx for three years ive done 4 piston changes and uncountable services. so i definitely know how to maintain MY race bike. BUT i know very well that i dont know exactly how to maintain a fourstroke. im just moving up to 250f because i age out of supermini this year. and i'm starting in 250B. so im probably faster than you :smirk:

and i'm debating whether i want to go to a 150sx or a 250sx-f. and don't worry i'm not insulted by anything anyone said. i merely wanted clean cut information from someone who has maintained them well over the years so i could decide whether i want to stay two stroke and what i'm comfortable on, or switched to the fourstroke. thank you all who gave me useable info. thank you

It's a lot of maintenance at your level. I'd guess you're going through pistons every few months and a bottom end every year, depending on how often you ride. You're going to have to add valve inspections to your regular maintenance, maybe every few rides. I don't know how money flows in your house, but if it's tight, I'd consider the two stroke. It's kind of hard to say though, because while the maintenance is cheaper on the 2-stroke, it's going to be more frequent, especially if you're talking about buying a 125.

this is a very difficult question to answer . there are so many variables. however if you are fast you will be putting enough load on that 4 stroke that you will most likley be into more money and maintinance than you were with yor 2s It is a more complicated motor and it is less forgiving than the 2. In the end you will start down the road in a new learning curve. If you believe you have the skill to roll with the change, and the expense, then through trial you will get to know what the 4 needs to live. BUT that just it. You will have to grind through the learning curve. Do you want to do that at this time? Maybe its more important to you to go the next seasion with what you know already. Only you can say.

The 4 is more money and more critical of maintinance than the 2.

Anyways... Routine oil changes (for race machines, do it often, like 3-5 hours, or every handful of races), check your valves before each race, clean your carb, fresh gas/clean tank, clean or new air filter, new spark plug, replace fuel lines with each oil change..

Not sure about topend rebuilds. As a complete shot in the dark, probably a new topend every race season, but i'm not sure.

that all sounds reasonable. i love working on it, so im surely not afraid of working on it, as for money flow, REASONABLE amounts of money or no problem for us, we arent tight for money but arent rolling in it. lol and ive rode my my friends new 250f (he just moved up last season) and i think ill hit the learning curve screaming (or "farting" in a 4strokes case! lol) thanks to all of you for the advice! :smirk: ride on!

faster than you
no doubt man im out of shape ride maybe twice a month, if ur so dam good why not just go race loretta lynn's and go pro. Good luck man.

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