Rare Scottish Tree Badger

Valve settings and timing ok? This is what I did to a warrior piston on a mate's bike. As soon as I got on it I knew something was wrong, but thought it was just something simple and slightly out of tune. I ran the bike for about half an hour on a trail having to back off the throttle to get any power as it got worse. I was in top when starting to climb a hill and dropped a gear, but within seconds, BOOOF!! That was it. ...... Turned out to be a bent valve that was the cause, chapping away at the piston until it snapped! Rare. Spot the valve! >>>>>

And did you work out why your tests didn't show up this "bad wire"? Rare.

What year is your bike? .... I don't see a green/ yellow wire in my Yamaha manual's circuit diagrams.

It will also allow you to slow down quicker when coming off the throttle, as there's less reciprocating mass. It's moreso the 4 stroke engines that have idle issues as they only fire once every 2 strokes of the piston. (The more pistons, the less of a problem it becomes). Rare.

Can't be your stator or cdi if you're still good on your right cylinder. These feed your coil which fires both plug leads at the same time, twice per rev. of the crank. Try switching over your plug wires and see if your problem swaps cylinders, which will prove a fault in the plug lead or plug cap. ... But I would have thought your left plug to be wet with oil/ fuel if this was the fault, and you say it's grey/ dry. Are you getting corect fueling to that left cylinder? Developed an airleak?? Rare.

Are you making sure that needle holding plate is going back on the right way round every time you make a change. .... The breather hole needs to be uncovered. And also your connecting hose between the two carbs. (This one I'm sure you're doing). Have you tried a 27.5 pilot or has it been a 30 throughout all your changes? Rare.

When doing your test for spark, are you removing the plug gap and testing for a spark to earth at about 4-6 mm? Did the replacement (known to be working) coil have it's own plug caps? Your pickup coil is at the minimum gap settings, but obviously working ok at that as your lights are trying to come on at kickover. Did you wire your kill switch into ... 1/ Your old key switch system R/B, 2/ your old run switch system B/W, or 3/ directly to the coil (or coil wire), B or sometimes the +ve side O. I think you're going to find your fault when checking your groundings. ... Hope so. I take it you're using an Ohms meter for all these wiring checks. Rare.

Well done MILO. Rare.

Wow, frocash...! That's a bit extreme! One of mine had snapped and I replaced them all with Grade 8's (8.8). ps. Your signature is class!! .... "Mother Nature told me I should get rid of my two-stroke because I was polluting too much. I roosted the stupid whore...." Rare.

Well Done! At least you've got a good starting point now. Rare.

Another couple of tips. ... For blasting: Once you've removed the steering stem bearing/ housing assembly, get two blocks of wood that are big enough to cover where the assembly goes. Drill a hole through the centre of both blocks and use a bolt to clamp them either side of the housing. (I used blocks about 3" square and 1/2" thick). For coating, your painter should have high temperature adhesive tape which can be used to stop paint getting where you don't want it. ..... The housing that you've protected for blasting. The protrusion that the rear master cylinder slides onto. Where the brake pedal slides onto. And errrrr??? .... wherever else you don't want paint to go. Rare.

I was told Cory aswell. .... I won a seat on eBay (to replace my stolen one), and the guy says it used to belong to Cory that owns Alba. BTW, he didn't say that in the listing to get more $'s, he told me afterwards. So I've no reason to disbelieve him. It's taking big air as I write! Shipped on Thursday and it's on it's way to Scotland. Rare.

Is there a link to these "verde" seat covers? Rare.

I just got my frame powdercoated in December. I used a mixture of setscrews (bolts) and rubber plugs. I didn't have a problem with the setcrews. But I was told to make sure that where the thread went right through, I was to keep the setscrews flush with the exit hole. The plugs that we used were cone shaped and came in various sizes. Some were hollow down the middle and some were solid. They were great. .... So easy and quick to fit and also simple to just pull out. Brilliant paint job! "Super Chrome Blue". Cheers Allan! I'd put up a pic, but I can't seem to be able to do it! (Never have!) My files are within the KB size, but it still says they're too big. . Could someone pm me to help out here, thanks. *Edit* ... I think I've goy it sussed! ... Looks better once enlarged, but even then it's not as good as my original. Rare.

Nope. It doesn't matter which way round they are, they both fire at the same time. (Twice per rev of the crank). Rare.

I would try going back to your original mains and see what happens now that you have your new NGK 8's. ... If the 9's were fouled up, that could have been causing your problems to start in the first place. My 8's were fine, but with a race port job, skimmed and worked head (std), I thought moving to 9's (B9EG) would work fine. .... I'm fouling up and after a bit of research have found that I'd have had to add in excess of 40 hp to warrant changing to 9's. .... Back to 8's again before my next ride. I'm going to try the EIX's. Was there anything of interest behind the stator cover? Anyone else got any ideas?? Rare.

What were your B9ES plugs like when you pulled them? On the old setup you say it ran well most of winter and now you say ... "Also, it had this problem with the old jetting & old plugs." Rare.

Should be in 'jetting and exhaust' with this one, but anyway. ..... We need to know what you've changed from and to: Old gas? _____ to new gas? ______ Old plugs? _____ to new plugs B8ES Old jetting? _____ to new jetting 340/30 How many turns out were you before on the slow running mixture screw? And now? What mixture ratio are you on? Your mods in your profile say 110 gas and 17cc domes. .... Any port work done? What altitude are you at? Rare.

Mee too! I just did mine last week, although I think it was pneumatic hose that I used. ... Worked a treet. Rare.

Are you using compressed air to blow through your jets when cleaning? Rare.

Yip, that's what he means. But take note of what he said about where to use the brake cleaner. I had the same problem with my bike a couple of weeks ago. With mine, as could be with yours, the brake lever is not usually pulled in all the way through normal use. ..... When bleeding the system, the lever's pulled in all the way and this can cause a breakdown in the seals. I couldn't get the piston set out as my circlip pliers were too big to get in there once the rubber dust cap was removed. ... Looks a tricky little set up in there! For a quick fix, I ended up putting on the master cylinder from my hardtail that's on an engine rebuild just now. .... I now have brakes. .... BMW style! Rare.

Nice one 'PUSH ...' Yip, that's the pic to use. Rare.