4 stroke maintenance

coastlinecascott 1/26/2016 7:40am
1/26/2016 7:40am
Since owning a carb 4 stroke, i found it fairly easy to work on. The maintanence is higher and more expensive (oil filters and oil). The fuel is cheaper. After it locked up over a triple from a bad cam chain Ive replaced the cam chain and topend. I got lucky since it was at idle with the clutch pulled in. No valve damage. Next go around is going to be all new oem valves, new seats, seals and all. That is going to be 7 bills easy. That still does not include oil pump and water pump for safety. So yes owning a 4 stroke in the long run is more expensive.
rtpilot
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rtpilot 1/26/2016 7:41am
1/26/2016 7:41am
Moto_Geek wrote:
That just great you can afford new bikes all the time and sell them before it cost you a lot. Go back and ask all the...
That just great you can afford new bikes all the time and sell them before it cost you a lot. Go back and ask all the people you sold your "low hour" bikes too and ask them how much it cost them now. Smile .
Great point! I completely agree. Yes, the new bike angle is quite a bit different from the used segment. Affordability was tough, I am not wealthy, but I would never buy a used mx bike. We have seen way too many people knowingly buy a clapped out bike for that magic price only to find out that the oncoming repairs would of been the same as buying new. I seen a lot of tears over the used segment. How many oil changes, how many times did the engine suck in dirt, and how knowledgeable were people that worked on it? Whether you buy a used 2 or 4 stroke, you toss the dice. Ok, a little off topic. If you do buy a used 4t and it grenades and repair it properly, you now have a very reliable bike for a good while, same thing with the 2t, but the 2t you have to stay on top of it. So is the 2t any cheaper in the long run? I think it's close.I know how hard people work to buy these things, and NEVER sell a bike with issues, as most people do. Unfortunately, this has fast become a very expensive sport, and the risks of used is a tough call. Whatever you choose, love the one your with. To ride is to live, everything else is waiting.(Steve McQueen.)
hillbilly
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hillbilly 1/26/2016 7:52am
1/26/2016 7:52am
When cam chains wear and stretch it makes the cam timing late and the engine lazy . It doesn't take much to get it off a degree.
MVmoto
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MVmoto 1/26/2016 8:36am
1/26/2016 8:36am
My father runs an off-road motorcycle riding school in So Cal and he has multiple Yamaha WR250F's with probably close to 1000 hours on them and they have never needed a new piston or new valves...

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coastlinecascott 1/26/2016 9:13am
1/26/2016 9:13am
hillbilly wrote:
When cam chains wear and stretch it makes the cam timing late and the engine lazy . It doesn't take much to get it off a...
When cam chains wear and stretch it makes the cam timing late and the engine lazy . It doesn't take much to get it off a degree.
The cam chain i pulled out was stiff as a board.
rbabb524
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rbabb524 1/26/2016 10:15am
1/26/2016 10:15am
I have had very good luck with my 4t, except my first one which was my fault since I neglected the maintenance. It was a learning curve for me. With that said, I will never buy a used 4t from someone. I don't want to buy someone else's headache; especially since so many people sell them before the problems start.
sandspider250 1/26/2016 10:26am
1/26/2016 10:26am
urbanlift707 wrote:
So someone tell me again how 4 strokes cost more to ride/race than 2 strokes. Don't get me wrong I love smokers too, I just don't...
So someone tell me again how 4 strokes cost more to ride/race than 2 strokes. Don't get me wrong I love smokers too, I just don't understand the argument that they are killing the sport and cost more to ride. Racing 250 two strokes I would get about 50 hrs outta a top end and it would cost me around $200 to replace that. I would also burn up a clutch in 50 hrs at another $100-150. My cranks would go at around 100 hrs and would be a top and bottom end at that point and cost $1000 to get back up to steam. Don't even start with me about 125's.....
On my 450 I replace my piston at 80hr, not cause I need one like I would on my two stroke(at 50 hrs), but just cause I feel like I should. It cost me $275, my clutch is fine cause it's a fing 450 and you don't need to clutch with all that torque. I've lost my bottom end on my last three 450's at around 130 hrs, at that point I do a bottom end, as well as a piston and cylinder to the tune of around $1,200. Maybe I'm lucky but I've owned a new 450 every year since 07 all with over 100 hrs and I've never touched a valve.
I usually sell my bikes around 150 hrs, the 250 has cost me about $2,000,three top ends, three clutches and one bottom end. At 150hrs my 450's cost me about $1,400.
Honestly I love both bikes, as each are a blast to ride, I've just never understood the cost argument.
You're just full of shit, that's all
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PC
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PC 1/26/2016 11:07am
1/26/2016 11:07am
Spend $30 and get an oil analysis. They will tell you how much your oil has broken down as well as contaminant levels. They will also tell you whether you can extend or shorten the OCI.

Buy a leak down tester. Dont just change your piston at 40hrs and have the seats cut at 100hrs because you 'think' its worn. Wait until you know it's tired before throwing money at it.

Check the valves after 1hr of break in so you have a static reference point to compare to as they wear.


I hope this helps somebody save a little $$
I have 6 bikes to maintain and I'd be broke as hell if I was replacing shit on a hunch.








hvaughn88
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hvaughn88 1/26/2016 11:39am
1/26/2016 11:39am
urbanlift707 wrote:
So someone tell me again how 4 strokes cost more to ride/race than 2 strokes. Don't get me wrong I love smokers too, I just don't...
So someone tell me again how 4 strokes cost more to ride/race than 2 strokes. Don't get me wrong I love smokers too, I just don't understand the argument that they are killing the sport and cost more to ride. Racing 250 two strokes I would get about 50 hrs outta a top end and it would cost me around $200 to replace that. I would also burn up a clutch in 50 hrs at another $100-150. My cranks would go at around 100 hrs and would be a top and bottom end at that point and cost $1000 to get back up to steam. Don't even start with me about 125's.....
On my 450 I replace my piston at 80hr, not cause I need one like I would on my two stroke(at 50 hrs), but just cause I feel like I should. It cost me $275, my clutch is fine cause it's a fing 450 and you don't need to clutch with all that torque. I've lost my bottom end on my last three 450's at around 130 hrs, at that point I do a bottom end, as well as a piston and cylinder to the tune of around $1,200. Maybe I'm lucky but I've owned a new 450 every year since 07 all with over 100 hrs and I've never touched a valve.
I usually sell my bikes around 150 hrs, the 250 has cost me about $2,000,three top ends, three clutches and one bottom end. At 150hrs my 450's cost me about $1,400.
Honestly I love both bikes, as each are a blast to ride, I've just never understood the cost argument.
sandspider250 wrote:
You're just full of shit, that's all
That's an interesting sig line you have there
Tom_May
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Tom_May 12/2/2019 1:19pm
12/2/2019 1:19pm
wreckitrandy wrote:
My experience with smokers is that most people don't want 'em to smoke. They don't like spooge running down their silencer. So, they mix their oil...
My experience with smokers is that most people don't want 'em to smoke. They don't like spooge running down their silencer. So, they mix their oil about 50 to 1. Sometimes even less oil than that. Try running your four stroke about half a quart low for 50 hours and see how they do.
Ran amsoil 80:1 in a 1982 YZ125.
Half tank Yamaha at 20:1 for break in.
Raced it for two seasons and rode it in the woods almost daily.
Never had that motor apart! No BS
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