Small 2t engines?

[kramdra]

What would fit my spare CBR250rr frame?

(I just ordered forks and yokes for it.. making it somewhat closer to being a full rolling chassis)

[SQL]

Anything if you can weld the frame, i'd be tempted to put a 200 exc lump.

[SQL]

or this

https://www.ebay.co.uk/itm/Yamaha-FZR250R-engine-1HX-/221366792425?pt=UK_Motorcycle_Parts_13&hash=item338a7d30e9

[Shaft]

Small capacity or physically small?

Since they don't have to accommodate cams, valves and their associated drive trains, strokers tend to be physically smaller than their 4 banger brothers, for a given capacity.

I've always fancied finding out what one of the most iconic stroker motors would be like, fitted to a bike with a modern frame, brakes and suspension.

Cram a Kwaka 750 triple in there, then let me have a go.
____________________
Things get better with age; I'm close to being magnificent........
20 RE Interceptor, 83 Z1100A3, 83 GS650 Katana
WooHoo, I'm a Man Point Millionaire! https://www.bikechatforums.com/viewtopic.php?t=234035

[Kickstart]

Hi

Depends how much chopping around you want to do.

Personally taking a CBR250 and using a different engine is throwing away much of what makes the bike special.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[SQL]

[Kickstart]

[G]

Talk to Chris and get him to fab up some stuff (if he still can) for an inline 4 250-500 cc? Should fit in the same space... just need to find somewhere to put the exhausts .

[c_dug]

If I remember correctly an old tdr250 engine can be made to take a rediculous cylinder Kit from a snowmobile. It makes it something silly like 800cc.

I can't remember where the kits are from mind, but I know I linked them for somebody on here before. Anyway. That's my vote.

Also kickstart is right, the engine is what makes the 250rr special.
____________________
I am a bellend, I am a man of constant sorrow, I am a gummy bear, I am a rock.

[_Iain_]

Maico 700.
____________________
Please be aware that the above post may be full of complete nonsense.
Riding: '07 KTM Duke II, Baotian BT49QT-20 Driving: '88 Volvo 340

[P.addy]

[SQL]

800cc snowbike engine

[skatefreak]

NSR 500 engine, if you could ham-fist that in there
Assuming you have a house to re-mortgage!
Any 250cc + Multi cylinder 2 stroke would be worth while
That being said.
I am a sucker for the old 2 smokes *grins*

-Jvr

[G]

Actually, see if they have any of these lying around...
https://thekneeslider.com/images/2009/06/tss1100.jpg
Though, it may be pushing the chasis a bit.

I was also thinking snowmobile - but you do need to bodge on a gearbox with them.

[kramdra]

Ofcourse no damage or modifications would be made to the frame.

I would love to put a cbr250rr engine in it, but the cost probably more than buying a whole bike - need ecu, loom, carbs, airbox, exuast and all the other little bits.

If i understand correctly 2t's are much simpler, and cheaper option. Plus Ive never ridden one

I do have the chinese 125 but I feel swapping that engine would be cruel.

[G]

2 strokes are both fairly simple and compact.

However, I'm still not convinced it'll be worth the hassle when you'd probably have a nicely working bike for less money and time buy just buying one.

A 250 motocross engine would make similar power to the CBR, weigh a chunk less. However, you're going to have either mount it off centre or mess with the outputshaft/chain etc.
The Parallel twins might make more sense, but don't really get cheap ones anymore.

You'll still have the off-centre issues, but as I've gone on about before, I'd be tempted by a pit bike engine. That also gives you the option of sticking a 50cc engine in, reregistering it as a ped and selling it some kid that wants to have the meanest '50' in the playground. Could also include a 140/160 engine to sweeten the deal .

[bezzabsa]

any of the KH motors..250, 350, 400, 500 and the H2 750

or Suzuki GT750 engine.....or if you have LOADS of cash RG500

[MarJay]

Waste of time and effort IMO. The only two stroke engine that you can get that'll be worth putting in is an RG500 and they are worth £5000 for a decent one these days.

You can take a RD350 (not a TDR) engine and put Banshee quad (not snowmobile) parts on it to make it up to about 535cc and about 120bhp, but again you'd be looking at spending about £5k just on parts, and that's before anyone builds the thing for you.

If you are going to put a two stroke in another frame it is better for it to be a narrow twin or single frame. An inline four frame is completely the wrong shape really, unless you're putting one of the wider fours in there, as mentioned.

The only thing that should be put in a CBR250 frame is a CBR250 motor IMO. The 400 is more suitable for larger engine conversions, and narrower frames are more suitable for two stroke conversions.
____________________
British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F; Cheap project: CBR900RR FireBlade
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

[Blau Zedong]

I'd like to fit an X5 engine. I looked at putting GSXR1100 Front and rear ends on a standard frame while mine was in bits and it's a non starter (the 1100 rear wheel rim is as wide as the rear tubes on the X5 frame).
____________________
18:54:48 Rob Fzs: jews don't give away stuff for free

18:54:59 Rob Fzs: unless its their clothes/ hair/ golden teeth

[c_dug]

[DMCpro]

Cb250 rs engine or cb400 if you can find one
____________________
Honda CB-1, TS125X
VW Golf Estate

[hmmmnz]

punsun v2 diesel 20hp of black smoke goodness
____________________
the humans are dead
I kick arse for the lord
Wiring Diagrams BIDNIP it bitches

[Kickstart]

Hi

Added problem for many bikes is mounting them. Having the engine mounts in vaguely the right place is quite unlikely, and many 2 stroke engine are rubber mounted (eg, RD LC, TZR250, etc), while the off road ones are likely to vibrate like mad.

Getting the brackets that will take the vibration and will go from the current frame will be difficult.

Add to that I suspect the engine on the CBR is structural to the strength of the frame.

Wiring everything up will be fun

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[Pete.]

Take 200 old laptop batteries, the motor out of an electrolux twin tub and a hoooooooooooge roll of gaffa tape.....
____________________
a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[Kickstart]