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Well, I picked up the 257 engine from Chris (Bruce off this forum) a few weeks ago, and now starting to make real progress on the project. I am doing the project at college, where unfortunately I only get one day a week to work on it. I've got a whole year, so should easily get it done. I'll keep this topic updated regularly, with lots of piccies


A lot of work is needed:
Need to make a new stinger pipe for the exhaust,
the powervalve needed rebuilding,
the rear engine mounts need a sleeve or bushes made up because the mounts diameter is larger than the bolt that supports it (the one that also goes through the frame and swingarm)
Cradle for the front engine mount
Electrics need rewiring
New coolant pipes
And a lot more which i cant really think of at the moment

I am gonna buy a lot of trick bits aswell for the bike. Adjustable suspension, race fairings, clip ons and some cf bits.

Here are the pics, and notes on whats been going on

Enjoy!

Obviously, the bike as I know it started life as a restoration project, purchased from Sunderland up north. This took some time, but eventually it went from this: (Bike hanging in foreground)



To this:



Then it suffered several serious engine problems over the summer, and I took it off the road. I then decided as, because I needed some kind of college project, to whack a 257 lump in it. I brought one of Chris, as well as the carb, ignition, front engine mounts, powervalve and a jolly moto exhaust that needed some work on.

Anyway, first week, I didn't have the engine by this time, so I just stripped the bike down at college. I brought it in like this:







Later that day it looked like this









A 250 single will occupy this space soon!



The next week, I had the engine. Here are some pics









I then decided to put the engine in the bike, to get an idea of the work required to get it a correct fit











The week after, I took the top end off









Decoking the piston: Before and after shots





I then fitted the engine with the front engine mounts, meaning it was fitted with no support from jacks for the first time



















Another problem encountered, the water pump outlet comes out close to one of the front engine mounts, this will be sorted out later



A few photos showing some problems we encounted when we fitted the engine. The front sprocket was hitting the swing arm, I am going to buy a smaller sprocket but the swingarm would need modifying aswell. The engine was also hitting the swingarm when trying to shuffle it along to align the chain. This meant I couldn't align the chain properly, so would need to be sorted out









I then removed the swingarm to commence work on modifying it. This was how I finished the week





This week, I spent most of the day modifying the swing arm. I also had help making bushes for the rear engine mount, which would remove the play with the bolt fitted. This is what the bushes looked like before work, an ordinary lump of mild steel



Unfortunately I didn't get any pics of the bushes before I fitted them. But here they are fitted to the engine





This one had to be cut down to allow for the engine casing



Here are some pics of the swingarm after I had adjusted it, very happy with this



It now easily clears the engine with enough room for proper chain alignment



And the same for the sprocket



Phewwww that took ages, anyway i'm up to date, next week i'm gonna make some spacers because the rear engine mount isnt as long as the gap between the two sides of the swingarm, this shouldn't take long... Refit swingarm and engine, and of course get some more pics


Cheers Steve!!
 

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looks groovy mate, man wish i had the chance to do things like that at collage, my collage sucked, thats why i quit, so im guessing your putting a 250 big bored engine into a 125 frame? is that an RS250 engine or something else? good luck with all the work dude and keep us posted i enjoyed reading it, i no you didnt have much luck with it when you got it back on the road
 

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nice are you doing a motorsport mechanics course?

looks like fun
 

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125cc Sportsbikes Supporter
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looks groovy mate, man wish i had the chance to do things like that at collage, my collage sucked, thats why i quit, so im guessing your putting a 250 big bored engine into a 125 frame? is that an RS250 engine or something else? good luck with all the work dude and keep us posted i enjoyed reading it, i no you didnt have much luck with it when you got it back on the road
I think It was originally a 250 enduro engine, they put out about 50bhp. Nothing like the RS250 engine as it is single cylinder and 1pv... unlike the twin cylinder 4pv RS engine.... making it much easier to fit into the 125. I think they make a non pv variant that loadsa people use in karting too.
 

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TZR: Smokey... Not Burned
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looks cool mate. keep up the good work. hope you get it all sorted..
 

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wat course you takin mate?
 

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good read mate good luck with it looks alot of fun
keep us updated what coarse you doing? im doing a car mechanics coarse(wanted to do bike but no college near me does it
) and they would never let us do out like that we just work on the heaps they have lol
 
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