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Questions tagged [two-stroke]

A type of internal combustion engine where all of the cycles of combustion occur in one 360 rotation of the crankshaft.

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What is the difference between a 2 stroke and 4-stroke engine?

I just wanted to know that what are the major differences in 4 stroke engine or in 2 stroke engine. The only difference I know is that a 4-stroke engine goes through four stages, or two complete ...
Helix Nebula's user avatar
2 votes
0 answers
23 views

Small edger engine - hard to start

I have a small edger 2-stroke that is hard to start. I cleaned plug, washed sponge air filter and it still won’t start. I sprayed starter fluid in air intake and it started. While running I put air ...
jlo-gmail's user avatar
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1 answer
286 views

two stroke engine with an oil pump? possible, why not?

so, in the two stroke engine, the fuel and air passes through the crank case, and it's said you can't have an oil sump in there because it would get consumed into the engine. However, I know like my ...
sergbot's user avatar
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1 vote
0 answers
64 views

2 stroke motorcycle is fouling spark plugs after stator change

I got a 1998 Yamaha TDR 125 (4FU) 2 stroke motorcycle. It has a Mikuni TM28SS/1 flat side carburetor. I recently had to change the stator coil (the previous one burned down, due to wet conditions), ...
Erik Csipak's user avatar
2 votes
1 answer
1k views

Poor man's 2-stroke strimmer air filter

I've bought a strimmer for a few quids and I've just managed to start it. However, the air filter is missing. The part is discontinued — or likely to cost me more than the strimmer itself in case I ...
ebosi's user avatar
  • 187
8 votes
3 answers
2k views

Can I dilute 2-stroke gas and run it in my riding mower to get rid of it?

Over the winter I needed a chainsaw, I mixed a gallon of gas for it and unfortunately it just refused to start which gave me the motivation to purchase an electric chainsaw which did the job ...
Sidney's user avatar
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2 votes
2 answers
496 views

Why are two stroke direct injection engines uncommon?

Traditionally, there have been two kinds of engines: two stroke and four stroke, and diesels exclusively were four stroke (apart from maybe very large marine diesels). The two stroke engine has some ...
juhist's user avatar
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Poulan chain saw

How do I install a new piston with 21 loose needle bearings around the wrist pin in the little end of the connecting rod? I have tried to install the wrist pin but the needle bearings keep falling ...
willie's user avatar
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1 answer
740 views

Two stroke engine with unreliable idle

I am currently restoring a Partner 22 GBI leaf blower and facing some weird issues. I have removed the carb, cleaned it in the ultrasonic and restored everything to factory settings. After running ...
Yanick Salzmann's user avatar
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0 answers
4k views

Carburetor not drawing fuel from tank

So the title is kind of generic, but I am facing a bit of a weird situation. I am going to explain it first, but I also have some pictures at the end that might help. I have bought a cheap 2 stroke ...
Yanick Salzmann's user avatar
1 vote
1 answer
166 views

How much performance change can be expected from changing 2-stroke mix-in oil?

I have a 2 stroke paramotor: Paramotor with a parrot on the propeller. It is a 235cc 2-stroke engine with carburetor fuel delivery and magneto ignition. The transmission is a direct drive pulley ...
tuskiomi's user avatar
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1 answer
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What's the power problem?

2-stroke marine engine (200 Yam) starts and revs just fine out of gear. Put into gear and will only achieve 40kph or so. Old petrol (50:1)? Changed tanks and new fuel - same. Boat hull dirty? A little,...
Tim's user avatar
  • 428
0 votes
1 answer
931 views

Compression testing a 2-stroke boat motor

On an outboard two stroke engine, what tests can I do with a compression tester, (and how to carry them out)? It's a Yamaha 200 hp V6 2-stroke boat engine.
Tim's user avatar
  • 428
1 vote
1 answer
563 views

Can gasket sealant be used to seal friction fuel connections?

I have a two stroke trimmer with a plastic fuel tank and plastic fuel lines. At some point, these lines have been replaced with new lines that don't quite fit in the holes the old lines did (~0.5mm ...
toxicantidote's user avatar
1 vote
0 answers
31 views

How can find if the CDI of my bike is working fine?

I have a 2001 Yamaha RX 135 2 stroke motor bike and have installed an aftermarket performance CDI which claimed to give me better performance and RPM rev. But since I have installed it I seem to feel ...
S.D's user avatar
  • 111
2 votes
1 answer
2k views

Chainsaw chain spins after start until I hit the throttle

Immediately after I start my chainsaw (Craftsman 358.350280), without holding the throttle, the chain moves fast. As soon as I press and release the throttle, it comes down to idle fine and the chain ...
David Doria's user avatar
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0 answers
247 views

Purpose and correct name of plastic inserts in 2-stroke cylinder

I recently replaced the cylinder and piston on a broken chainsaw 2-stroke engine and I found 2 plastic inserts inside the cylinder. I'm wondering what purpose these serve, and what the correct name ...
Unimportant's user avatar
1 vote
1 answer
163 views

Which engine type gives more HP- two or four cycle?

Same max. RPM and CC of course. And if possible, an explanation would be nice. Thanks!
asdfghjkl's user avatar
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1 vote
0 answers
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Is back-pressure (or air-intake suction) of ANY value to a typical little(20-->50cc) 2-stroke engine? Like chainsaws, blowers etc [duplicate]

Have been searching for this answer for a while, typically I look for an answer & give-up when nobody can provide one but this time I'm going to learn the truth!! For chainsaws, weed-eaters etc, ...
2-stroke-q's's user avatar
0 votes
1 answer
1k views

CC per HP in a 2-stroke engine?

I have a bunch of 2-stroke engines and the websites that I found only tell me about 4-cycle engines. Do you happen to know the ratio of cc to HP?
asdfghjkl's user avatar
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1 vote
2 answers
2k views

Exhaust back-pressure Q on simple 2-stroke yard-equipment engines:

I am having trouble getting a precise answer- is back-pressure necessary on a little single-cylinder 40cc 2-stroke like a chainsaw or a blower? I ask because people frequently modify mufflers to ...
2-stroke-q's's user avatar
0 votes
0 answers
33 views

My Two Wheeler scooter - Powers OFF Intermittently while driving

I am using a two wheeler (Petrol/Gasoline vehicle). I haven't driven the vehicle for like 30-40 days. Today I had a trouble turning ON the vehicle. After some tries, I managed to turn it ON ...
Newbie's user avatar
  • 101
2 votes
0 answers
323 views

Does a 2-stroke engine needs "break-in" after replacing cylinder and piston?

I just replaced cylinder and piston (with new gasket, rings, etc) in a 2-stroke 52cc string trimmer engine. It started at the first pull and sounds great, I let it run for 5 minutes, adjusted the carb ...
devapo's user avatar
  • 21
0 votes
2 answers
494 views

1966 Suzuki K11 Oil Change

Got a old suzuki that's running and working just fine. I got the fuel ratio for the bike which is 20:1 this a two-stroke. What I'm trying to figure out is the oil for the bike. Normally do 10w30 or ...
fassetar's user avatar
  • 322
1 vote
1 answer
80 views

How fast a 2 stroke engine wears, how much fuel it consumes(compared to a 4-stroke engine) and how to properly mix fuel with oil [closed]

I want to buy a 2 stroke engine to build a minibike. I am 15 years old and i never owned a 2 stroke engine before. I know they wear faster and consume more fuel than a 4 stroke engine. But how fast ...
Randomouss Stuffed's user avatar
0 votes
0 answers
41 views

Boring Engine Cylinders

I owned 1978 YAMAHA 175 Enduro (2 stroke) and i had to bore the engine cylinder and now i am using 1.00 piston in it.But i noticed that it's not speeding up above 80,when it reaches 80 it's like ...
Githendra McShane's user avatar
0 votes
1 answer
261 views

Primer bulb not drawing fuel

I had an old 21cc two stroke weedwacker engine that I had lying around and was trying to rebuild it for use in a possible hobby project. It sat with gas for a very long time so I disassembled the ...
maple_shaft's user avatar
0 votes
1 answer
620 views

Craftsman Leaf Blower wont start, ignition coil failure?

In a previous question I asked about repairing a carb for my leaf blower and the repair didnt hold so I bought a new one. Replaced fuel filter and fuel lines, also replaced the carb gasket. I seem to ...
maple_shaft's user avatar
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0 answers
14 views

chainsaws&blowers: Any guides/instructions on installing DIY air pre-filters on units with weak OEM filters?

I really love the idea (in link below) of Echo's 'pre-filter' setup to ease/assist the actual/main air filter and would love to DIY something, am guessing a stiff-enough, heat tolerant mesh material ...
C.TraversZaxar's user avatar
2 votes
1 answer
1k views

Two-stroke engine seizing at full throttle

I have an odd problem with a 50 cc air-cooled two-stroke scooter engine that keeps locking up at full throttle, then freeing up again. I just bought the bike second hand with a new belt needed ...
Contino's user avatar
  • 21
1 vote
1 answer
93 views

This seemed a good spot for engine-stuff, so: What are some ways that *may* lead to greater power in a chainsaw?

This seemed the best area to ask since it's not a tool question so much as an engine question, I use a high-end premade fuel and always have a sharp or sharp-ish chain, am just hoping to learn the ...
C.TraversZaxar's user avatar
2 votes
5 answers
7k views

2 Stroke engine magneto ignition system

I've got a 2 stroke 1 cylinder engine and its ignition system doesn't seem to work. I'm having problems with my magneto ignition system and I need help connecting everything up. I think I've ...
PotatoMan's user avatar
0 votes
2 answers
3k views

50cc Scooter only runs when manually choking air intake

I bought a 50cc Yamaha Zuma off of craigslist, and it's had some aftermarket parts put on it (exhaust, 70cc big bore kit, new carb). I cleaned the carb and converted the throttle to a one cable set-up ...
Sam Koebrich's user avatar
1 vote
0 answers
373 views

Johnson 9.9 2 stroke wont idle anymore

I have a 1999 Johnson two-stroke 9 hp outboard motor. I have a 10 foot pelican that I put it on but the other day I almost flipped the boat after making a sharp turn, water got all in the boat about ...
Lazaro Puentes's user avatar
1 vote
0 answers
597 views

1997 Mercury 9.9 HP 2-Stroke starting issue

I've been banging my head on a starting issue with the outboard motor mentioned in the subject line (it's a manual pull-start). Problem is that when I pull it over, it doesn't sound/feel like it even ...
stevieb's user avatar
  • 133
0 votes
1 answer
91 views

Turn push/pull motion into up/down?

I don't know if this is the right place to ask, but I have an RC 2 stroke engine with a choke with an arm that requires up/down motion to open/close. The problem is I can't place a servo below, so I ...
Dacobi's user avatar
  • 103
4 votes
2 answers
1k views

If an engine starts does that mean compression is fine?

I am looking at buying a second hand 2-stroke engine. I have seen a lot online about checking compression before buying used engines. I don't have a compression tester, but will buy one if necessary. ...
Swag_B's user avatar
  • 43
3 votes
2 answers
356 views

Diagnosing a boat that wont start

Having some problems with my '92 Boston Whaler Rage jet-boat again.... See this post for all relevant boat info: Starting a 2 stroke jet boat after several years Ok, so I did basic troubleshooting, ...
Calvin's user avatar
  • 489
0 votes
1 answer
132 views

Two stroke engine stalls during incle

Sir I have 1967 two stroke Harley Davidson golf cart. It runs great on level ground but when I try to go up a incline hill it wants to stall and it only makes it up the hill using the choke. I changed ...
Robert Snyder's user avatar
2 votes
1 answer
2k views

2 Stroke making choking sound on full throttle after carb replacement

I have a Yamaha RX 135 which is a 2 stroke bike, and I have replaced it's carburetor , Previously it was stock 26mm round slide mikuni carb , and its been replaced with 30mm Flat slide mikuni. After ...
GeekWithGlasses's user avatar
2 votes
1 answer
8k views

String trimmer revving too high at WOT?

Someone gave me a 52cc string trimmer for free because they say it wasn't working. We would only get it started by dropping a few drops of fuel into the cylinder, and it would idle quite high for a ...
jxma's user avatar
  • 21
2 votes
1 answer
250 views

How to clean a muffler from the inside?

I want to clean the muffler (final exhaust pipe) of my motorcycle (2004 Cagiva Raptor 125). It is a 2 stroke engine so a bit of oil has sort of... sedimented on the inside of it. How am i supposed to ...
Andrei Grigore's user avatar
2 votes
2 answers
5k views

Too much smoke in my 2 stroke

I have a 2004 Cagiva Raptor 125 and for the last week it's been letting out smoke a bit too hard: I have had the bike for a year and a half now. I did an engine rebuild as soon as I got it because ...
Andrei Grigore's user avatar
2 votes
3 answers
3k views

Oil sump for 2 stroke vehicles

I do not know if there is any oil sump for a 2 stroke vehicle and basically it is mixed along with the gasoline. Why is that so in a 2 stroke vehicle. And can we have an oil reservoir or a sump of oil ...
DhKo's user avatar
  • 1,155
2 votes
5 answers
2k views

Two-stroke vs four-stroke design

Besides the apparent differences in fuel-injection, ignition, and valve timing, are there any other differences in the design/build of two-stroke and four-stroke engines?
ManRow's user avatar
  • 303
2 votes
0 answers
115 views

Weed Wacker Not Running Properly

I have a Remington weed wacker that is ~2 years old. It worked great for the first 2 or 3 months but then I could not get it to work properly. I have tried new gas, new plug, adjusting the idle on ...
Steve Salowitz's user avatar
4 votes
2 answers
3k views

Adjust carburettor without hi-speed adjustment

I've got a Walbro WA226 with no hi-speed adjustment screw. Unfortunately, it seems that the issue is in the high-speed jet. Adjusting the low screw can set me up so long as the throttle is at full, ...
anonymous2's user avatar
  • 5,235
9 votes
2 answers
933 views

Carb. Rebuild or Adjustment?

Just put a rebuilt 2 stroke and brand new Mikuni SBN carburetor in my jet boat. Got her running no problem the first couple times, now it seems I can't get any gas into the carburetor from the primer ...
Calvin's user avatar
  • 489
3 votes
0 answers
214 views

Jet Boat, Cavitation or Misfire?

My jet boat is making a 'putting' noise when trying to accelerate. You can find all details regarding my boat here: My Boat Info The noise seems to happen in the mid-rpm range; 4,000 - 4,800 RPMS, ...
Calvin's user avatar
  • 489
5 votes
2 answers
15k views

No compression on my two stroke

I was recently riding racing my Honda 250R (1986) (informally), and, all of a sudden, the engine quit completely. I tried letting out the clutch in second gear (push starting) with my momentum, but ...
Cullub's user avatar
  • 1,364