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About HyperGlow

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    New Zealand

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  1. HyperGlow

    YZ85 coolant coming out of headbolts

    Sounds like everyone has got you sorted already, but I noticed in the pictures it looks like the dome head nuts have been used on the cylinder and the cylinder nuts on the head, they are around the wrong way and as already mentioned there should be copper washers under the head nuts. Hope you get this all sorted!
  2. HyperGlow

    Would ya run it?

    Looks pretty hectic, is that some pickup on the cylinder wall? You can clean it off with phosphoric acid which is a bit of painstakingly slow process but I have done the same on my 125 years back but that was just a small amount on a relatively new cylinder. Prob wants a re-plate to be safe.
  3. Yep, as already mentioned it's for the Throttle Position Sensor which was only for the one year (2004) on the CR125's but was on the CR250's for a few years I believe. You can convert from the Mikuni carb to a Keihin PWK AirStriker which JD Jetting sell, and I would recommend it as it's easier to jet and provides noticeable increases in crispness and power. I also had trouble with the throttle slide on the Mikuni's cracking pieces off and getting sucked into the engine. I own an '04 CR125 myself and made the switch to a Keihin back in 2011, I have owned the bike for coming up 8 years and it now has close to 400 hours on it. The Keihin has no TPS attached to it and therefore the wiring is not needed, why this I don't know but James Dean said it was fine to leave it off. Hope this helps!
  4. HyperGlow

    Ideas for your discarded Mikuni TMX (OEM Honda)

    I had the same thing happen on my CR125 2004 the Mikuni carb slide cracked off both corners and got sucked into the engine. The bike was about 100 hours old at the time. I replaced the slide and within 7 hours it had a hairline crack in it again so I switched to the Keihin PWK Airstriker setup with JD Jets. It seems like the Mikuni slide would hit on the end of the slide rather than hit the little stopper tab and eventually crack.
  5. HyperGlow

    Siezed engine after 10 minutes.

    I have now done an hour on the bike and have spent the last few days working on the jetting. I have the Keihin PWK Carb with JD jets and first off I tried it one clip leaner than it was on the Blue needle ( 2nd from the top to the top position), but it felt a little lean in the midrange and still had a bit of a bog in the lower revs. I then switched to the Red needle which is slighly leaner than the Blue at 0-1/4 throttle openings and set that at the 3rd from the top position, it felt perfect right through the range but the spark plug looked slightly lean so I lowered it one clip but it spluttered too much in the midrange and wouldn't rev cleanly so I set it back on the 3rd clip again and checked the plug colouring compared to some pictures and I think it should be okay I think. It's funny how one clip positon will make so much difference but I think I have it fairly good now, the Marlborough Motorcyle Club has their end of year ride day at the Club track this Saturday at 1pm so I will try get to that (our ute is in pieces at the moment but hopefully fixed soon) if I can make it and see how my bike performs there. Geoff, I'll be in contact soon about the other measuring the other piston and payment. Do you like Venison? I shot a 230 pound Red Stag on Tuesday and I can give you some of that as well as some cash if you want. The pressure tester I used was one I made myself based on the one here: http://www.thumpertalk.com/topic/432226-pressure-testing-a-2-stroke/?hl=%20pressure%20%20tester I also went to Blenheim Engineering the other day to find some measuring tools like yours but they didn't have much which suited my size of bore, I'll keep an eye out for a telescopic snap bore guage and a micrometer though.
  6. HyperGlow

    Siezed engine after 10 minutes.

    I've been meaning to update this for ages but have been so busy with weddings, funerals and xmas things etc but I returned the Wossner and exchanged it for a Pro X in 53.94mm and installed it a while back, I have now done about 25 mins on it and it seems to be running well other than needing the jetting leaning out a bit possibly since we are in Summer now. Geoff, I have meant to make a time with you to get the other Wossner I got 30 hours out of meausred just out of curiosity and I would like to pay you in some way for the help in getting things all measured up. I took some pictures of the bike the other day which I'll post up as requested, most of the plastics are new spares I have which I put on just for the photos.
  7. HyperGlow

    Siezed engine after 10 minutes.

    Thanks for the info Geoff. I have contacted the shop I got the piston off and they will exchange the Wossner for a Pro X in a 53.94mm so that should sort out the clearance issue, That will probably arrive early next week. He did tell me this info about the Wossner coatings which I didn't know though: "Wossner pistons already have the recommended clearance built in. Skirt diameter is smaller than the recommended bore size (see sizing on box). Some applications: Nitrous, supercharged, turbo, and cold water marine engines may need more than the recommended clearance. Wossner clearances are set before coating. Coatings are 0.012mm (0.00047") thick and should be deducted when measuring for piston to bore clearance." Interesting to know but I'll go back to a cast piston for now anyway and see how that goes. I'll post up some pics of my bike when she's all back together, I think it still looks quite nice for the hours I have done on it! Itching to get back out riding, it's been too long.
  8. HyperGlow

    Siezed engine after 10 minutes.

    So I've been away for the last week or so but before I went, Geoff was kind enough to measure up my piston and cylinder. The cylinder was well within spec and was in good condition other than the alluminium pickup it measured 54mm if I remember right. The piston on the other hand measured 53.97mm even though the Wossner box had it labeled as a 53.95mm. The clearances were too tight, so even though the top of the piston was stamped "A" it sized closer to a "C" which Wossner sell. Not sure whether that's a machining fault of Wossner's but either way the piston was too big. The plan now is to buy a new piston to suit my cylinder size and Geoff will measure it before I put it in just to check clearances. I need to get around to cleaning up the alluminium off the cylinder for now so will have to have a play with that.
  9. HyperGlow

    Siezed engine after 10 minutes.

    Thanks for the help Geoff, I have sent you a PM.
  10. HyperGlow

    Siezed engine after 10 minutes.

    Here are the pics of the cylinder:
  11. HyperGlow

    Siezed engine after 10 minutes.

    Muratic acid is just sulfuric acid isn't it? What strength would you use it, does it need diluting? I'll post some pictures of the cylinder damage and see what everyone thinks about whether it can still be used or whether it needs replating. After a fair bit of reading I think this has all happened due to ignorance and lack of tools on my part, I obviously need to get myself a micrometer and a cylinder bore gauge for measuring clearances before I put the piston in. This is a step which up until now I have never done nor known about after the 10 or so top ends I have done and I guess I have just been lucky to not have this happen before. Does anyone recommend any brands or where I could pick up some good measuring tools? They actually have a fair amount of information on the site I purchased the piston kit from which I should have read I guess: http://www.motocrossparts.co.nz/motoxparts-motorcycle-parts.php?id=128 The part I don't understand is the honing of your cylinder to seat every set of rings, I always have heard never to bore a nikasil coated cylinder as you will ruin it as seen here: Thanks guys for all the help so far!
  12. HyperGlow

    Siezed engine after 10 minutes.

    The company I emailed has forwarded it to there technical team to look into so I will hopefully hear something back from them soon.
  13. HyperGlow

    Siezed engine after 10 minutes.

    The cylinder was bought brand new about 60 hours ago from Motosport and is an OEM. The whole ring is still intact and looks fine. My 2004 model only has two sizes "A" and "B" unlike the Yamaha's etc. which are "A" to "D". I would say it was very unlikely that it went lean as it had run fine up until I replaced the piston, it was almost close to fouling the plug after idling for so long and the slow running when I did the first break in session. The head hasket is completely intact and shows no signs of wear. Here is the link to the gaskets I bought: http://www.motocrossparts.co.nz/motocross-parts-accessories.php?id=2500&biketype=2&fitsbrand=3 I live in New Zealand so in the Southern hemisphere the weather is warming up, but no significant changes in temperature. I was riding in about 20 degrees celcius. That's interesting to know, I was taking it easy and was planning on doing 3 heat cylces even though the piston came with a slip of paper suggesting two was enough. I was genuinely surprised when it seized at realtively low speed. And also such a tight seizure, I have seized a bike twice before and both times they came loose as soon as the bike cooled but in this case the kickstarter was stiff and it took quite a bit to get the cylinder off.