125cc to 250cc conversion

[Muncy]

Hey fellow Ace owners,

As the topic says, I have decided to swap out the 125cc motor for a 250cc version.
I fell in love with the look of the Ace 125 and knew I had to have one. Coming from 600 supersports bikes I found the bike lacking in horse and stopping power. But the style and feel of the bike made it a project I was keen to do. I rode the Ace home (17km) and tore her down to her bare bones.
I have a bit of mechanical skill such as servicing my bikes and rebuilding the left hand side of my CBR after an accident. But other than that I have limited mechanical knowledge. The Ace resource topic on DTT has been a great help and appreciate anyone who posts in there.
Hopefully I'll be able to do the same and help you guys out, but for now here is my project. Cheers Trav


Here are my bikes. 2003 Honda CBR600RR, 2013 Ace 125, 2008 Suzuki GSXR600

After much research and excitement I purchased a OHC 250cc vertical cylinder engine. I know a lot of you guys have gone for the ooracing big bore kit, but the value for money and power for that matter was a better option/choice for me. (This may bite me in the bum if I come along any difficulties... but fingers crossed). I'm excited to work on resolving any issues and if it costs me a bit more so be it. It's all about learning and the journey for me.
Here is the engine I bought. It was a black version as no silver was in stock. No biggy.
http://www.ebay.com.au/itm/250cc-Zongshen-OHC-engine-motor-motorbike-motorcycle-/260874027190?pt=AU_Motorcycle_Parts_Accessories&hash=item3cbd4dc0b6&_uhb=1

I began to tear down the Ace and found that the bolts/screws/etc were all pretty secure and that everything was tight. (Have heard of screws and what not falling off fellow members bikes).
I was hopeful that the engine would at least fit into the main frame. I was half expecting that the brackets may have to be changed/cut off but was pleasantly surprised the main rear brackets fit. The top support bracket doesn't match up but the 2 plates should able to be fabricated pretty easily hopefully. Then the bottom front bracket doesn't match as well. Same deal, I'll hopefully get one fabricated to match. I'm glad it's those 2 brackets that didn't fit as I can physically take them off and take them to a fabricator. Pic of the engine in and I have also put the brackets on to illustrate how far off they are.

Here is the wide shot of how the bike sits.

I have checked the exhaust and the flange and dimensions fit perfectly. I have yet to do the exhaust modification where you cut out the cat. But that is on my list of things to do. I'm looking at getting this exhaust.
http://www.ebay.com.au/itm/Chome-Reverse-Cone-19-Muffler-Suit-Cafe-Racer-Triton-Norton-Triumph-BSA-/300837622048?pt=AU_Motorcycle_Parts_Accessories&hash=item460b51d120&_uhb=1

When unpacking the engine I noticed a 6 pin green connector. I feel stupid for asking but does anyone know what it's for?

I know the black one is for the starter solenoid and the white one for the regulator, but i'm unsure of what the green one does??

So that's it for about now. I'm going to check the sprocket and the chain length\width\pitch but it looked good at first glance.
I have a big list of things I need to do and need to buy so here it is. I'll add the links of where I most likely will get them.
Please feel free to comment and add anything that I may of missed.

- Front brake pads\rear brake shoes HH rated. Does anyone have a good site to get them?
- Stainless Steel front brake line - http://www.helperformance.com.au/build-your-own-hose-0-1m.html
- 30mm Mikuni Carb - http://www.ebay.com.au/itm/MIKUNI-30mm-CARBURETOR-200cc-250cc-Pit-Dirt-bike-Thumpstar-Quad-Hummer-Orion-/200735981567?pt=AU_Motorcycle_Parts_Accessories&hash=item2ebccbffff&_uhb=1
- 27mm clipons - http://www.ebay.com.au/itm/27mm-Clip-Handle-Bars-1-pair-Silver-color-/261418769454?pt=Motorcycles_Parts_Accessories&hash=item3cddc5dc2e
- Bar end mirrors - http://mostynindustries.com.au/product-category/handlebars-mirrors-and-grips/
- Jets/needles/air filter etc - http://www.dimecitycycles.com/
- tyres/tubes, going to try the Michellin or Pirelli's.
- sparkplug - NGK dpr7ea9 - http://www.supercheapauto.com.au
- coil pack - http://www.ebay.com.au/itm/RACING-NGK-IGNITION-COIL-PACK-110cc-125cc-150cc-250cc-ATV-PIT-PRO-DIRT-Quad-BIKE-/261328539411?pt=AU_Motorcycle_Parts_Accessories&hash=item3cd8650f13&_uhb=1


Ohhh and I'm going to do the modification to put the battery under the seat cowl too.
I think that's it for now. Hope you enjoy the thread and I'll try and take some more and better pics for you as I work on the bike.

Safe riding,
Trav

 

[Hazza00]

Looking fwd to the documented transformation and progress pics of your project, Trav ...

Wishing you every success with it.

Haz

 

[Dave M]

Hi Muncy

This is a project I am going to enjoy! I am waiting for an ACE 125 to arrive at my local dealer along with a 250 engine - I ordered mine from Skyteam and it is the engine they fit to the 250 Raptor that they do. I asked if I could have the bike without an engine but they said it was not possible so I guess that will have to go into another project!

Before you get much further with your build check out the swing arm mounting plates. they are outboard of the frame and are simply two 4mm or so plates. I have my doubts about them being up to a 250 and am going to brace them with two similar plates welded inboard - There looks to be plenty of room for this and it should stiffen the whole lot up. I'll probably fully weld up the outer plates too.

The back brake is also shite in standard form but I want to keep it as a drum - I am very keen to keep the bikes looking period and fairly 'standard' - However I have modded my back brake quite heavily and it seems to have improved it to the point of being able to lock it up. The main problem, apart from the pathetic size of the drum, appears to be the mid mounted crank - the actuating arm is shorter than the actuated one making a reverse lever action. I extended the short arm, modified the rod from the brake lever to be adjustable and turned the back brake rod upside down to reduce flexing. I also had to mod the actual brake pedal to clear my silencer and to raise it up giving it more adjustment. The pics should help to see what I mean!

I am keen to swap notes on this as obviously we are doing the same thing in essence but I don't want to hijack your thread - let me know if you are happy for me to contribute, bearing in mind that I am hampered by not actually having the bike or engine yet! It was supposed to be here at the beginning of March but wasn't. Don't want to whine though coz they did me a cracking deal and I want to keep the whole thing pleasurable.

cheers

Dave

 

[Dave M]

Oh yeah............ Don't know how I forgot this but I fitted shocks from NJB Shocks in the uk - What a revelation - unbelievable improvement and with out shrouds they are only £72 Mine were £92 with shrouds and P&P..........

Short Goldie sounds ace! Left Ooracing pipe std length, blocked end with alloy plug - drilled one 12mm hole in it and three 6mm ones, then drilled 12 off 15mm holes radially in the pipe - makes it 'reasonably' quiet (well OK 'reasonably' loud!) but lets it go...

Dave

 

[Muncy]

Hey Dave M,

Thanks for that info. Like yourself I'm concerned about both brakes. I'll upgrade my pads and front line and see how that goes...I've even thought about replacing the rear drums with a disc/caliper setup.

Please feel to post anything you like.

 

[Dave M]

Thanks for that - I'm gonna chase em up Monday to see when it's all arriving!

I wondered about a rear disc but hate to beaten and have persevered with the drum - it is now good but out today and it's not a wheel locker! I am going to try drilling the sprocket mounting boss to create a fan that blows across the brake - I vented my brake plate, see earlier posts - to blow all the crap out (and heat). Every time I strip it it is full of brake dust!
However some Chinese commuter bikes appear to have disc rear brakes and I have been eyeing some up as donors......

Dave

 

[stroker crazy]

This is going to be an interesting project!

Even with better pads and s/s brake line I think you might find the front brake inadequate with the extra speed and weight. The back brake definitely so.

As a bigger rear tyre would help get the added horsepower to the ground, perhaps a rear wheel could be found with a wider rim and better brakes.

Looking forward to seeing how this turns out.

Crazy

 

[Dave M]

A scheme that I have considered for the front end is to get another disc fork leg and mount it on the other side so I had one calliper in front and one behind. I have seen some very early racers done like this - Nortons I think, but I can't find any pictures.

It may mean that I can't run the speedo from the front wheel like the standard set up but I'm sure I'd get around it

It would look nice and retro but be a twin disc set up.

BTW I am running the Skyteam front pads and the front brake is excellent - so much so that I have not bothered to put EBC pads in...

Dave

 

[ACEitup]

BTW I am running the Skyteam front pads and the front brake is excellent - so much so that I have not bothered to put EBC pads in...

I've had the same experience,
but I have really bad spongey front shocks!
cheers ACEitup

 

[Dave M]

Called into Earnshaws Bike shop in Huddersfield today to ask for an ETA on my bike and engine. Apparently it is in a container at sea on it's way from China! Anyway, no sweat I can start amassing other stuff to put on it. I had a look at a 250 Raptor whilst I was there - a horrible thing to my eyes - The engine looked nice though. I suspect that the front mounting plate from the Raptor will fit an ACE with the 250 engine but I will make one anyway.

Had to leave pretty sharply as there was a danger of Kawasaki W800 purchase!

The special off road one Earnshaws do is stunning!!!

Dave

 

[Muncy]

Hey guys,

Sorry for the lack of updates, but the project is still going.. but slowly because of me. Been busy with a few other priorities and have unfortunately ruptured my ACL in my knee. Makes it a bit difficult working on the bike, but the old girl is getting there.
I haven't been taking many pics to illustrate the changes as I've been too excited or gun ho to get in there and do it. I apologise for this.

So far I'm waiting on a new front bracket to be fabricated and also the top two engine mounting plates as well. While I'm at it, I will get my exhaust extended to suit. I've heard good responses on here that increasing the length of the headers improves the low end grunt.

Good news is that I have installed my 30mm carburettor and filter, handlebars, new front ss brake lines and bar end mirrors.

I don't have the latest pics but have a pic to show things are slowly progressing.

I have since added the levers, grips, throttle etc on to the handlebars. This was just a quick mock up to see the angle I wanted to suit my position.
At the bottom you may be able to see my carby and filter.


I'll try and get the latest pic(s) this weekend and show you the progress.
Muncy

 

[ChrisBNE]

Look forward to seeing the progress!

 

[ACEitup]

Hey All,
emailed Adrian from ooracing today
I asked him about 150 big bore kit and when it would be in stock?
He told me another 3-4 weeks they were at sea as we speak.
I also asked him about a 250 conversion kit ???
He replied they are in stock and doing tests and making them into kits at the moment
and would be releasing pricing mid next week !!!!
thoughts everyone ?
cheers ACEitup

 

[josephau]

Is definitely official, they have just announced on their FB page!


從我的 用 iPad 發送

 

[cafe59]

Just read that OORacing have managed to produce 18bhp and 100mph at 9000rpm with their 250 engine kit. The first Ace that has done the ton! It's fantastic but... How is the rest of the bike going to hold up? How about all the shitty parts? How about the terrible breaks, front fork, frame?

 

[vonmighty]

I agree. I often wonder if my bike will fall apart under me just doing 60!

 

[stroker crazy]

How about the terrible breaks, front fork, frame?

How does the skinny back tyre cope with the extra power?

Crazy

 

[Eelsk89]

Not sure if you have figured out what that green plug goes to but on my lifan 200 I put in my cb125 it had a 6pin green plug like that it went to a gear position switch just below and slightly to the left of drive sprocket

 

[cafe59]

I often wonder if my bike will fall apart under me just doing 60!

Yes exactly! Can't imagine doing 100mph on that thing. And definitely can't imagine stopping quickly at that speed!

 

[vonmighty]

Hey Muncy, I am considering swapping my engine out for a 250 along with some of the other crap parts..

What other engines did you consider?