The big maintenence lie?

[AFJ7732W]

I often hear about how much less maintenence there is to a 2 stroke, than a 4, mostly from guys on 2 strokes. However the 2 stroke guys like to change the piston and ring after about a year of riding, or 250 hours. It takes about an hour and a half to do that. Costs aprox $150.

I am going to have my valves checked in my 07 WR450 once a year. Last year they were all well within spec, so no money was spent on parts. It didn't take me any time. I paid the dealer to do it, and it cost a lot less than $150.

So, it seems to be a "top end job" vs a valve check. We change our oil a lot more, but they mix gas.

What am I missing? How is the 2 stroke less maintenence?

[2005_xr250l_thumper]

less complex engine means that if you throw a rod or something that damages your engine, the two stroke would be cheaper to rebuild and simpler.

[stevenacarter77]

very good answer !!!

[FORMA MOTO]

Top end failure on a Two stroke is almost never catastrophic, unless you ride it with detonation for a long time. It usually runs until it looses power, but will start.

Top end failure on a four stroke is sometimes catastrophic, and will stop running if the you get a leaky valve. Then it will not start.

An abused and neglected four stroke can take out an entire motor!

A top end on a two stroke can be done by a 9-year old blind girl for under $200.

A top end on a four stroke usually requires precision machining of several parts, a highly qualified specialized mechanic, and $ 1500 bucks.

[WR_Dave]

Both engines, if they were equally maintained, would give several years of service with minimal maintenance costs. The 2T uses up a piston and rings every year or 2 and gets regular oil changes and needs mixed gas. The 4T needs regular valve clearance checks, regular oil changes including a filter and an occasional timing chain. The big difference comes when there is an engine falure or problem. While the piston and rings on both aren't drastically different, when you get into cylinder and cylinder head repair the 4T costs go up 5 times what the 2T costs would be. This is why regular service with quality products on the 4T is so important. The 4T on most brands shares the tranny and engine oil ( read -clutch and gear shavings debris ) on the 2T the oil change is for the tranny only and the engine is lubed by the mixed fuel. Again, with quality products and quality service, both types will give long enjoyable service life. These costs and service intervals also depend on how the operator runs the machine, an abusive rider will up the costs on both and a rider who is easy on the machine will have alot less extra expense on either machine. WR Dave

[123BigcoopDawg576]

A top end on a four stroke usually requires a highly qualified specialized mechanic, and $ 1500 bucks.

This thread is great...I am not qualified and the last two top ends I did were well under 800 bucks.

1) My dads 06 WR450 had 13K miles when we did his topend....we replaced the piston and rings, valve seals and valve springs....we put the stock valves back in and the stock shims...started first kick...total cost was around 300 bucks (I would like to see a 2 stroke go 13K miles on the same topend)

2) My buddies XR600 we did the whole topend valves and all...parts cost around 700 bucks. Again once done, started right up. This was on a 16 year old bike....can you get 16 years on a stock 2 stroke? NO ?

[CanadianWR450]

Not to hi-jack or anything, but for a 4-stroke, how often should you replace the valve springs, and what do you look for as a indication that they should be replaced?

[bills442]

"mixing gas" and "changing four stroke oil" aren't even CLOSE to being a comparison. It's takes me < 10 seconds to measure a quantity of oil and dump it into a container.

[bills442]

This thread is great...I am not qualified and the last two top ends I did were well under 800 bucks.

1) My dads 06 WR450 had 13K miles when we did his topend....we replaced the piston and rings, valve seals and valve springs....we put the stock valves back in and the stock shims...started first kick...total cost was around 300 bucks (I would like to see a 2 stroke go 13K miles on the same topend)

2) My buddies XR600 we did the whole topend valves and all...parts cost around 700 bucks. Again once done, started right up. This was on a 16 year old bike....can you get 16 years on a stock 2 stroke? NO ?

An XR is NOT a valid comparison to a modern 4 stroke. Noone would question the reliability of an XR's old school, low revving, low compression, steel valve motor; however, many would question the reliability of *some* modern MX 4 strokes. Yamaha seems to be one of the better ones, and this report seems to verify that further in my mind.

[123BigcoopDawg576]

Noone would question the reliability of an XR's

I thought we were talking maintenance not reliability...to me replacing a piston once in a blue moon is maintenance ?

None the less I have yet to a yamaha 4 stroke cost some one an arm and a leg to rebuild.

My buddy's crank finally went in his 426 a few months back...800 bucks later we rebuild it (again put the original stock valves back in - I would like to see that with a honda )

Lets do the math 800/8 = 100 a year and people are talking about doing 100-150 dollar piston changes on a 2 stroke. I simply fail to see how 4 stroke are sooooooo expensive

[FORMA MOTO]

This thread is great...I am not qualified and the last two top ends I did were well under 800 bucks.

1) My dads 06 WR450 had 13K miles when we did his topend....we replaced the piston and rings, valve seals and valve springs....we put the stock valves back in and the stock shims...started first kick...total cost was around 300 bucks (I would like to see a 2 stroke go 13K miles on the same topend)

2) My buddies XR600 we did the whole topend valves and all...parts cost around 700 bucks. Again once done, started right up. This was on a 16 year old bike....can you get 16 years on a stock 2 stroke? NO ?

Yeah, I was quoting shop retail prices, for shock effect.

16 years on an XR600? Sound normal to me! I got 24 on my XL600R!

You can't compare that motor to any other motor made, accept maybe a Chevy small block!

[02WR426Cali]

"mixing gas" and "changing four stroke oil" aren't even CLOSE to being a comparison. It's takes me < 10 seconds to measure a quantity of oil and dump it into a container.

I think he was talking more about the cost of oil over the year and not the amount of time it takes to change or pour. Oil costs are probably about the same for a year.

[Bumperlt]

2 strokes require oil changes as well, for thier gearbox, I would say as much as regular oil changes on a 4 strokes because the clutch is what kills the oil.

[WR_Dave]

I don't know about the rest of you , but I answered the question in an average Joe's costs per the life of the machine basis. I wasn't trying to enter nor do I want any part of any pi$$ing contest. Nothing personal, to each his own opinion. I am a mechanic so my costs would be very much lower than say the guy who takes everything to the stealership if we are starting to include labor etc. over and above the parts it takes to "maintain" and repair the machine. WR Dave

[llamaface]

(I would like to see a 2 stroke go 13K miles on the same topend)

My record is about 7000 miles, on an 02 300exc.

For sure, the yamaha 4-strokes have an excellent reputation for reliability, but for me personally, an advantage of a 2stroke is that I can do the work myself, whereas some of the 4-stroke work involving valves or cam chain installs I don't really feel confident to do on my own. It just requires a higher level of expertise and more tools as well.

I also generally prefer riding a stroke, but sometimes I get in the right mood and really enjoy riding my 4strokes too. ?

[123BigcoopDawg576]

I don't really feel confident to do on my own. It just requires a higher level of expertise and more tools as well.

I felt the same way until I "dove in" and tried. I was surprised at how EASY it is...aside from timing a 4 stroke, the basic rebuild of a top end is the same ?

[Ebs]

When this discussion comes up I think people are more concerned with cost then actual time spent on maintenance. A 2 stroke guy might have to do a top end for $150 every year and a 4 stroke guy might only have to check/adjust the valves, but when it come times to rebuild that top end it will typically cost much more to do so.

[123BigcoopDawg576]

but when it come times to rebuild that top end it will typically cost much more to do so.

How so...if you rebuild a 2 stroke every year for 8 years compared to one rebuild of a 4 stroke at the end of 8 years. IMHO its even ?

[Charles De Mar]

My record is about 7000 miles, on an 02 300exc.

For sure, the yamaha 4-strokes have an excellent reputation for reliability, but for me personally, an advantage of a 2stroke is that I can do the work myself, whereas some of the 4-stroke work involving valves or cam chain installs I don't really feel confident to do on my own. It just requires a higher level of expertise and more tools as well.

I also generally prefer riding a stroke, but sometimes I get in the right mood and really enjoy riding my 4strokes too. ?

If she sees this your getting dumped!

[SJMC_DON]

I've owned nothing but WR's (5 now).... I have never done a top end on any of them.

I check and adjust my own valves, change my own timing chains and the most I have ever torn one these motors down was to replace a broken kick shaft stop on my 99' 400:worthy:

Now my son, who is now 17 yo and switched from XR's to 2T's at the age 12 has cost me nothing but time and money on motor work... we both race and ride about the same amount but with routine top ends and the occasional cylinder or re-plating it gets expensive:banghead:

Having said all of this, I think that a 2T ridden and maintained by an adult is far less subjected to the abuse that of which a teenager administers:foul:

For arguments sake.... I have had both in my garage for many years and I like my Yamaha 4T when it comes to operating costs and reliability ?