4-stroke engines quieter?

How2

New Member
Joined
Jun 18, 2008
Messages
7
hello all... noob here.

i've been told that 4-stroke engines are quieter than 2-stroke, but that they require more maintenance (ie. oil changes, etc)

In your opinion, which is the quietest motor and why? Are mufflers effective and what is your experience with them, if you choose to answer with mufflers as a component in your answer.

Thanks!
 
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HoughMade

Guest
4 strokes are quieter than 2 strokes- no doubt. Mufflers help, but all of these engines require some sort of back pressure to run correctly so running without one is not a good idea. I suppose a guy could run a straight pipe, but it would just be loud and performance would not really be better.

There is not more maintenance with 4 strokes, but the type of maintenance will be different. No oil changes with 2 strokes, but plenty of other things to mess with...of course there is the mixing oil in the gas every time you fuel up.
 

How2

New Member
Joined
Jun 18, 2008
Messages
7
4 strokes are quieter than 2 strokes- no doubt. Mufflers help, but all of these engines require some sort of back pressure to run correctly so running without one is not a good idea. I suppose a guy could run a straight pipe, but it would just be loud and performance would not really be better.

There is not more maintenance with 4 strokes, but the type of maintenance will be different. No oil changes with 2 strokes, but plenty of other things to mess with...of course there is the mixing oil in the gas every time you fuel up.

Thanks for the response Houghmade.

Initially, the oil mixing on the 2-stroke seemed like a bother to me. But everything i've been reading seems to indicate that overall, they are easier to maintain.

I currently have an electric bike, but i've run cost comparisons and find that a gas motorized bike is a better way to go. Battery costs are killing me!!! Even if gas goes to $30/gallon, it will still cost less to run a gas motor bicycle than an electric bike due to battery prices.

Sooo... I am going to motorize my other mountain bike and use it for longer distance trips, and keep the electric for the "close to home" trips.

I have much research to do to figure out what motor kit is best for me.

Thanks again!
 

Mountainman

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Joined
Jun 15, 2008
Messages
3,572
From the old guy --- 2-stroke - fast on the top end - wind them up - louder for sure - less torque on bottom end - very fast on top end - high revs ------------- 4-stroke - quiet - more torque bottom end - no mixing of oil with gas - more moving parts - valves, push rods, timing chain ect.
Happy Riding from - Mountainman
 
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HoughMade

Guest
It really depends on what kind of 2 stroke you are talking about.

These cheap chinese 2 strokes- fun and many people enjoy them, but they are maintenance intensive. You are always messing with some sort of adjustment and tweaking something.

A higher quality 2 stroke, like for instance, the Tanakas will likely be less maintenance. There are more moving parts in a 4 stroke- but look at what we are talking about- in the case of my Honda, after the first 10 hours (oil change and adjust valves) maintenance is very infrequent- beyond just keeping an eye on things. In any event- with quality 4 strokes or 2 strokes, we aren't talking about weekly adjustments, or even monthly adjustments (engine wise at least, bike likely will need adjustments) once everything is running right, there is little to worry about either way....but the 2 stroke will always be louder.
 

eljefino

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Joined
Apr 13, 2008
Messages
249
4-strokes emit a lower frequency noise that blends better with one's surroundings. People go deaf on lower frequencies first so 2-strokes seem louder yet.

Lacking a gas gauge, it is often difficult to know how much fuel one has remaining when they buy fuel... which makes mixing 2-stroke oil to the right ratio a challenge when one is off touring. If they exclusively use a premixed can from home this isn't such an issue.

If both were the same price, reliability, and power output I'd go for a 4-stroke instantly!
 

ZnsaneRyder

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Joined
Jun 19, 2008
Messages
805
I notice that 2 strokes have to be adjusted a lot. Another thing is they bog a lot until they are hot. For that reason I want to go with a 4 stroke. I'm about to get a 3.5HP Horizontal-Shaft Briggs&Straton engine for a bike trailer. I've never had much trouble keeping a lawnmower running good, so that's why I decided this engine, it's similar, but has the shaft like a go-kart engine. The engine is from an edger, and has a small pulley already on it. I'm making a clutch using an idler pulley, and a cloth woven riding mower belt so it can slip some when clutching. The axle has a 6-inch pulley and small 10 inch tires, so hopefully my ratio is low enough.

I'm hoping a cheap muffer from a tractor or car can quiet the engine down a bit though, but it's still much quieter than a weedwacker or chainsaw engine.
 
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L

Large Filipino

Guest
I like the 4 stroke because it's quieter than my 2 stroke. It also runs cleaner so you can muffle it better. I tend to over oil my 2 stroke Happy Time so that black oil drips from the exhaust so I opened it up making it louder because I got a serious clog before I did.
On the 4 stroke since the oil is in a bath the emissions is alot cleaner so you can get away with an exhaust that's quieter with no real worries that it will clog up.
I also like that you simply pull up to the gas pumps to get your gas without worrying about mixing. That to me rules.
 

ZnsaneRyder

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Joined
Jun 19, 2008
Messages
805
I agree. I'd hate to mix oil if I had to fuel away from home.

And for a 4-stroke, oil changes are no problem, being they take less than a quart of oil!
 

kymics

New Member
Joined
Jun 5, 2008
Messages
12
I thought I read somewhere that you're not supposed to fit external mufflers to 4-stroke engines like the EHO35 because it can hurt the engine.

But I do notice that when it comes to frame-mounts, the HuaShang and Honda 50cc 4-strokes have a similar muffler used on the HT kits.

The built-in muffler on the rack-mount kits seems pretty small, so am I right to assume that a frame-mount Honda would be quieter than a rack-mount Robin Subaru?
 
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