TommyNad

I know this will start a long discussion... but....

TODAY... who makes the best 90 size four stroke engine.... It seams that no matter how big a 4 stroke engine I use, It seams like it just cant keep up with a two stroke that's half the weight and twice the power....

Thanks
[email protected]

RaceCity

If there were truly a "best" .91 4C engine.. there would be only one to choose from, and EVERYBODY would own that one engine.

Yes, this WILL start a long and painful discussion that has been hashed through 1000 times already.

Do a review of the posts thus far. Use the search function. Base your decision on what YOU want, what YOU can afford, and what is important to YOU. Not me.

Happy shopping.

'Race

Mettler1

Check the weight of a 2stroke after you add the muffler and you will find the weight between a 2s and a 4s is not that great.

YS is probably the most powerful 4s. After that it's pretty much of a level playing field

NM2K

My Feedback: (14)

Also, don't forget to add the weight of the extra fuel you will need to carry just to fly as long as a four-stroke engine flying for the same amount of time. YS and engines burning 30% nitro excepted.

Flyboy Dave

My Feedback: (21)

The YS .91 is clearly the most powerful of the 15cc 4-strokes.

They'll probably whoop the pants off an OS .91FX 2-stroke.

Dave.

Checklst

Flyboy's right my 91 fx is running as good as it gets in my 4*60 but a Friend of mine has a YS 91Fs in his 4*60 and he pulls away from me like no tomorrow. I guess that little air pressure box really kicks butt.

MEMPHISBELLE

My Feedback: (24)

I have four SAITO .91's on a DON SMITH B-17. I have 74 flights on this plane and have landed the plane 74 times with all four engines running. I can start all four within 90 seconds and have never had one not start. I am using master airscrew 14x7 three blad props and turn 9200 r.p.m.. There is a 150 r.p.m. difference between all four at crusing r.p.m.. You couldn't get me to buy any other four stroke engine for any amount. I am now planning my DON SMITH B-24 with the same engine combo.


B-17, THERE IS NO SUBSTITUTE!!!

Richard L.

My Feedback: (24)

The best four stroke is this:



I can pull away from those whiney two strokes any day of the week.

Hobbsy

My Feedback: (102)

That engine is too clean Richard, you haven't been using it right. But I love my .91 FZ too.

PatternFlyer

My Feedback: (182)

Interesting. I have run total of 5 YS 91AC/FZs.

Yes, they are the best and strongest after proper break-in and setup compared to other 91 size 4-stroke engines.

Just for comparison purpose, I run OS 91 SX-H with a 140 tuned pipe.
Yes, it is a heli engine, but almost identical to 91FX with only 0.1 hp difference. 91SX with 15x8 on 140 tuned pipe runs stronger than YS 91AC/FZ. Total cost was almost same.

THESCALEMAN

LASER!

Dauntae

Why Yes I'll vote for YS, Gotta love the power.

Dauntae

Pancho

Guys, been that the power is not an issue, but “the troublesome”…which could be the simplest, the most reliable and the most realistic sound 4-stroke engine?
…what about the Saito 1.20?

dany_maia

Hi.
I also have the Saito 91 and absolutly love it.
Allways handstart, idle and transitions wonderfull and is the most beautifull engine I ever seen.
I have seen the OS 91 surpass II and they run great too so you have to choose.
I like the Saito a lot more.

bigbri

My Feedback: (287)

got to throw my vote in with the YS's
b-

ajcoholic

My Feedback: (10)

Having owned and run Enya, OS, YS, and Saito (and even 3 older Webra 4 strokes), I think they are all great engines. Sure, the YS puts out more power per cubic inch than the rest, but today, buying an OS, Saito or Enya will get you a great reliable engine for many many years.

I have no personal experience with Magnums, ASP or Thunder tiger 4 strokes (two strokes, yes). But for the small price difference I would go with one of the other brands above.

AJC

RaceCity

Allow me to be crude....

Why doesn't the original poster go to his local field and see what works well there?

The whole idea of suggesting a "BEST" engine is crap.

Best for what?

The mere fact that he doesn't have a clue rules out the YS engines....That's like recommending a Ferrari as a first car...complex and easily ruined.

4C's in general make lousy "learning" tools IMO...unless you all are prepared for 65,000 more threads to solve his problems.

If "pulling away" is all that's really important...I'd suggest a turbine. Ridiculously complex, but fast!

Enough of this nonsense.

"Beware of the the troll"

'Race

ajcoholic

My Feedback: (10)

What a rude posting. If someone wants to start with a nice 4 stroke, so what? My 15 year old student did just that this summer with a sweet OS .52 surpass and has not one problem all summer.

There is no magic to running a 4 stroke. Fuel up, set the needles and fly... two strokes can and many are, just as "tricky" to tune.

AJC

RaceCity

Oh well....


We've had OS, YS, Saito, Enya and a dabbling in TT and Magnum engines mentioned.

You could pick up any magazine and arrive at the same level of confusion. What has or ever will be accomplished by any of this?

Nothing. Absolutely nothing, and there are hundreds of these dead-end threads that all end the same way.

Have we all lost our decision making ability?

The truth is painful.

'Race

Hercmate

Racecity,
Regarding your last post in this thread........

Why, what will that achieve? Why should you be allowed to be so crude?

Not everyone has exposure to all makes of 4 strokes, I certainly don't.

I've been running 2 strokes for about 4 years now and I'd like a 4 stroke sometime soon. The fact that i've never run one makes me inclined to read threads such as these. In TommyNad's eyes (and mine too) 'best' probably means a good balance between power, weight, reliabilty and ease of use.

No it doesn't, not everone is a fool. I know two people whose first 4 stoke was a YS and they're doing fine.

Beware of rude posters more like. Are you the guy who stands at the field and criticises the newcomers instead of being helpful?

I'd suggest you either post something helpful or not at all. Thankyou.

RaceCity

Herc

We agree that the "Best" should actually mean a balance of factors. That's not what you're gonna get with a question seeking absolutes to a question that doesn't have an absolute answer.

I'm not beinig critical of the poster...and I'm not the guy standing around passing judgement at the field. I've had 25+ years in the hobby to do it, but have resisted so far.

You will find, that the best is in the eyes of the beholder and all the back and forth mess on this forum won't change that.

Don't like my post? OK.

I'm speaking my thoughts.

'Race

RaceCity

What is the BEST flavor ice cream? What is the BEST color of car to buy? What is BEST size pants?

When anyone can answer those questions with an absolute answer, that applies to all.... you may feel free to criticize my logic in questioning the validity of the original post.

Until then however......

Hobbsy

My Feedback: (102)

I have been thinking about this, my first RC engine was an Enya .46 MKII fourstroke we both survived my learning, no problem. In this size engine range I have YS .91 FZ, Saito .80, Saito .91 and a Saito 100, all would serve his purpose. The YS is a fine engine but takes nothing away from the Saitos, it weighs 7 oz more than the Saito 100. He asked for our advice based on our experience , and based on my experience, any of the engines mentioned here will do the job except of course the Enya.

Crash90

My Feedback: (17)

I think that there are definate answers to this question given enough information.

1) What plane is it going into?
2) Does the plane require nose weight or tail weight with a Brand X 2 stroker.
3) What kind of flying do you prefer? Pattern, sunday flying, or Extreme 3D?
4 Do you want speed or torque?
5) How much prop clearance do you have
etc
etc

Given that information we could offer a little more help.
I am getting ready to build a U-Can-Do 3D and I will be installing the Saito 100. Because it is lighter than the YS and I dont need the extra nose weight.
On my Tai-Ji 60 I installed a YS because it could benefit from the extra weight.

I think the main part of his question has gone unanswered.
" It seams that no matter how big a 4 stroke engine I use, It seams like it just cant keep up with a two stroke that's half the weight and twice the power.... "

When you say "It cant keep up" what do you mean? If you're a little more specific here we could give you more specific answers.

bla bla

I agree with Racecity.
What is "best" in one persons opinion is rather irrelivent... best for what?
I certainly wouldn't recomend YS to anyone other than the well seasoned. They are quite simply a pain in the ass at times, I own several! They need maintainace, anyone that tells you differently just hasn't run then enough, they need the right fuel(read they most expensive) and I wouldn't use 'em for anything other than what they where designed originally for, pattern.

If your sports flying, your better of with a decent sports engine. OS, Saito for example.
As for the old 2 stroke, 4 stroke who's got the most power, it's the two strokes, hands down.
I can't pull the same sized verticals with a 1.40 YS as I can't with a 1.40 OS.