Options, Options, Options but which ones the best?



  • As said, you won't gain anything from the 3MB00P barrel, only lose power.

    Sounds like to me your mind is set on using the 3MB head on the stock barrel so just go with that.

    My advice would be to pocket the spare dosh you have, and keep an eye out for a 3XP00 engine.



  • 4FU will produce the best power curve,

    3MB P is nothing without changing the PV and Ignition timing to suit, working off a 4DL Map was a good start for a novice tune.

    Excellent midrange improvement, really needs more fuel to increase power on top though, so you should look at Carbbies to



  • so where I stand currently.

    I could buy basically new 170 kit second hand for 250, sorts my rebuild out. I also have the offer to the whole DTRE engine and the kit for 300. This is why it’s an option.

    The 4FU would be sick, but most likely it’ll need replating. https://flic.kr/p/2iXJyT
    For what I paid I’d be a lucky man if it didn’t. Also looking around and 4FU pistons aren’t cheap, the cost would work out about the same as the kit and whole engine 😞
    ![0_1588640047048_561AEB96-28A5-45A7-A5A5-0CA4CF03E8AB.jpeg](Uploading 100%) y

    Then there’s P which I recently inspected and found a rather dubious line running through the powervalve. https://flic.kr/p/2iXJEiX

    think it might have been replated at some point or some kind of modification as it looks like someone’s filed the bottom of it by its legs, think it’s the case transfer?? I’m not sure

    Also buying a Zeely is now out of Zee budget.. for now at least. I wanna see why it’s so fabulous and the difference in it between the stock 3rm-30



  • Personally I'd stick with a stock 125 set up and look for a 200cc engine.

    I'm in a similar position with my Belgarda TDR as its a bone stock 125 with Dellorto carb and original exhaust.

    My original plan was to build the bike with a 200 engine but I've been unable to source one so far and will stick with the 125 for the build whilst in lock down.

    I also own a DT200WR so dont want another 3XP engine but quite like the idea of a DT200R one as it will go straight in, look the same and the pipe will line straight up no messing. Ideally I'd like to put some 200R parts onto / into my 125 casings and retain the electric start (its also got kick start as standard).

    Next time I go to France (who knows when that might be...) I'll look for an engine but until then I'll build mine as a 125. I did also consider the Athena option but have not heard anything positive so far about them so have discounted that one.

    Dont mind spending the money for something thats decent and quite fancy the idea of having a TDR200 that looks like Yamaha made it that way - already got the alloy swingarm ready to go in 😉



  • @Nottsbiker All about that TDR250 is you ask @scrimsmustang

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  • @Calum

    Thanks but I put 200 not 250 although I do know that SM has built many Yamaha's over the years and he had a WR200 and WR250Z when I had my first DT200WR so appreciate his detailed and extensive knowledge - just need him to magic up some DT200R engines 🙂



  • I did see you put 200, but I'm not familiar with that model. Rarity may be against you, the 250's are easier had.

    You not what I wouldn't mind?

    alt text

    Yamaha SDR200! YPVS Too!



  • Sorry I wasnt being funny 🙂 just talking about making my own home built 200 like Yamaha could have built

    Yes the SDR200 - rare and expensive now and oddly with a different engine to both the 3XP and 3ET 200's - looks like its based on the old 200LC motor.



  • I don't know if they are rare. They were not sold over here which is why we don't see them. Sold in Asia. And yes it is of the LC age, late LC 1988.

    I don't know though, there is something I just like about them.



  • Yes they look good - kind of a merger between an RD125lc and a TZR125 but with a nicer looking frame

    Only ones I've seen lately are all going for £3k+ right now so definitely look like people want them to command such high prices



  • @Calum i not long ago passed up the opportunity to buy a full 89 sdr engine because I want sure how I’d go about using it. I’m gutted now. They didn’t want much either.



  • @Stevie-Wonder they claim to be a Conservative 34hp which would be nice.

    I don't think 3k is too bad especially as you see people wanting 3k for an Aprilia



  • @Calum 34 would be nice. About the same as a WR200. It’s also worth mentioning that the SDR200 bottom end doesn’t bolt in like the others and I’m not even sure top ends are interchangeable. I couldn’t find any info on here about that



  • @Stevie-Wonder Yeah I don't know much about them to be fair. But they look pretty sweet.



  • @Calum * just to update what I was saying. I just remembered who it was I was talking to and it was a couple of the TZR Belgarda boys. He says the lower mount of it is all wrong and because of the electrical start it makes the SDR motors very ideal and highly sought after by them as a direct engine swap. Unfortunately not much good for us though



  • Well I mean, I quite like the whole bike.



  • Yes only the WR / R motors are a direct swap - think the SDR has an extra rear mount but I've never seen one in the flesh for maybe 20 years now.

    £3k isn't much I know especially as they wont lose any value



  • @Nottsbiker yes it does, it’s what the Belgarda boys where telling me as I had asked if they where using that motor whey they’d never used the 3XP. Also update
    I now have a full 4FU. valve head and barrel.
    I still have the P but that’ll get sold to fund the 4FU. Unfortunately the guy with the 170 never got back to me so I set my self a challenge of finding a 4FU valve in under a day by the evening.

    Looking forward to the day I run it and it seizes, nicasil liners and the extra rebuild cost is what initially stopped me going anywhere near I kmx and now here I am 😂 Do you think I’ll sacrifice much reliability with the 4FU?



  • @Stevie-Wonder maybe, I really don't like nikasil i appreciate it but it's not something is want to run



  • Nikasil plating is fine. There is no compromise in reliability? Why would there be?

    The tolerances can be made tighter. There is greater heat transfer between the engine and the coolant, meaning you can push the engine harder for longer.


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