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519 Topics 5.1k Posts
  • Flywheel washer and nut

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    ConnorDTRC

    @dan28 Cheers buddy, but i've gotten it sorted now. Appreciate the offer.

    Found an m12 washer fits, however it is too wide so it has to be ground down. But I got a washer from my college which was off of another bike that fit

  • Two big end bearings

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    CalumC

    The TZ is the full GP race bike.

    I doubt you will need it. I buy wossner forged rods which come with big ends and you'd like to think they are good quality.

    I personally would say just get the normal one or OEM. Really rods and big ends should be replaced as a pair.

  • Sluggish until powerband

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    D

    Done that, it lines up and goes through its sequence with no struggles. All cables are clean and it looks like a brand new pulley

  • FAQ Top End Rebuilds, Running in, Common Problems

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  • SLOW DTR

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    CalumC

    @DevonDtr All very simple things you can do yourself....this is a forum and we can help you.

  • Reed block spacer

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    S

    @Calum cheers man ! I put it before along with carbon reeds and it made a good difference in the bottom end , got it sealed and made a gasket out of gasket paper I had lying about , thanks for the reply !

  • Clutch slipping after transmission oil change ?

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    Biker_123B

    Thanks @Calum

  • Using a lot of 2 stroke oil after rebuild ?

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    CalumC

    @Leftyno1 so no. The bike shouldn't consume that much oil. The oil pump is a sealed system and either you will need a new one. Or premix.

  • Best premix ratio for dt125r ?

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    Biker_123B

    Thanks! very informative reply there I've never thought about it like! Yeah looks like I'll be riding differently now I'm mixing the fuel defo wouldn't want the engine seizing again happened before due to this oil pump so this seems the only way to go

  • Where to buy good quality gaskets

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    CalumC

    Pjme go and buy the Athena engine gasket set. Cheap at 20 quid and you can ensure good quality. Even the head gaskets!

  • Running in after Re-bore mileage to be done ?

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    CalumC

    I always feel that would you really feel comfortable riding a bike flat out only having tested it with a warm.up warm down procedure.

    There are other reasons why you should run an engine in. Piston ring and cylinder wall glazing can occur if you don't follow an appropriate run in procedure.

  • Normal spark plug Vs iridium ie Denso IW27 or NGK BR9ES

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    CalumC

    So what I mean is that a set of superfire plugs for my starlet is £100. Personally that isn't worth the money. A set of iridiums are £30.

    A spark plug for a dt is what 6 quid. And iridium is 9 quid. So its not a lot of money. They are supposed to last longer but if your bike runs overly rich or lean then sure it will wear an iridium faster. But thats not a fault of the spark plug.

    I don't swear by them. But I have always ran them. For no reason other than they cost more, so that must mean they are better. Poor logic for sure.

    I have no experience with the pedmoto but they look good. If they're stainless steel then they should last longer than a dep which was my gribe with the dep.

    As for the oil blanking. I would remove the oil pump. Oil cable and oil lines and tank. You need to gap the oil line from the inlet manifold to reed block as this will cause an air leak.

    The other one is that there is a cog driven off the crank shaft that drives the oil pump. Although the oil pump is removed this cog will still turn. So remove the cog clutch cover to stop this cog for spinning. Freeing up 0.0000001% parastic loss from the engine. Every horse counts!

  • Cancel oil pump - yes or no?

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    CalumC

    That's a point. Yeah at least if you remove the cog you could leave it all in tact. Choice is yours.

  • Clutch plate installation

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    M

    Thanks Calum!
    Got it sorted out today. Ready to fit the engine again in the next few days, can't wait..

  • Base gasket thickness

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  • Autolube rebuld

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    R

    In a similar position myself, here's a exploded view of the internal components:

    http://www.boats.net/parts/search/Yamaha/Motorcycle/1969/AS2C/OIL PUMP/parts.html

    I had to stretch out the plunger spring as it lost some of its original force and wasn't returning down.

    Replace the internal seals also. They are cheap from simplybearings.co.uk, just standard shaft lip seals, sizes are 4x9x3 and 14x25x5

    p.s. always take photos as you disassemble stuff, for this exact reason!

  • oil pump stroke

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    R

    Yes that's what I thought, but the stroke should still increase at any speed if the pulley is depressed? I'm sure I gave it enough time as it went up/down a few times?
    I took the pump off the engine, and a load of oil ran out of the pump where worm gear shaft goes into the pump body. Is that normal? There is a gasket there, but is that worm gear cavity supposed to be full of 2T lube?

  • Using kn filter on dt

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    CalumC

    Just copy and paste the link mate.

    Yeah, my advice would be to have a shield made that would shield it from the majority of exposure. Not uncommon practice for air filters.

    As said I've never had an issur and I've ridden in all sorts.from sunny to torrential rain. But perhaps your situation may be more difficult.

    Some photos might be handy here so we xan visualise the problem.

  • Crankshaft replacement!

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    CalumC

    Yamaha do a ruthless two stroke race bred machine called the TZ. The TZ is a full Grand Prix bike. So presumably it runs some sketchy kind of little end bearing.

    http://pages.ebay.com/motors/link/?nav=item.view&id=201394504785&alt=web

    That's the rods I use. Very high quality. But PJME recommend Long rods for generic builds. Mines supposively tuned.