So Close!...
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@stevie-wonder In the 15 years I have been riding smokers, I have never had one seize on me. In fact I know more people who have had four strokes go wrong. On fact I have had more four strokes die on me than two strokes
My Cagiva is in dyer need of an engine rebuild, yet starts on the button every time. The fact of the matter is, MX are finding this too, four strokes are great up until they go wrong. Then they become extremely uneconomical to fix. Two stroke engines are so simple that any home mechanic can rebuild them. But four strokes the tolerances are much tighter and therefore less attainable for home mechanics.
If you are into bikes you wouldn't bother spending the money on a new four stroke. You would get a used smoker.
I also wouldn't buy a DT knowing what I know now. They are pretty shit if I am honest. Bang for buck I would get an Aprilia all day long.
For 90% of people ig really doesn't matter. They need something to go to school on etc. But winds me up when they put an exhaust on it and it sounds AWFUL! and literally like no performance gain
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@calum
I think I do know what stevie means about the 2/ curse, I think it’s more of the idiot factor of not putting in 2/ oil has created a myth. 4/s are just more idiot proof...If the Chinese flooded the market with 2/s they’d be a status quo betwixt the two. As it goes I hardly ever see a smoker on the road
tis a shame, there used to be sooo many to chose from...
As it goes 2/‘s seem to be enthusiasts only. No new blood. The new buyer people have flooded the market with 4/s, no?... -
@spookdog But that's what I'm saying, 2 smoke is enthusiasts. The youths are no longer interested in buying smokers. Maybe they never were, maybe people would just buy whatever was available and it just so happened to be that two strokes were the go to.
My point still stands, youths aren't interested in smokers. It's now just an enthusiast thing.
And Two Strokes still dominate the MX realm and they're making great strides with Two Strokes. Fuel Injection is now common place in the smoker scene. As well as AWD MX bikes
If you haven't checked out Cristinis AWD Motorcross bikes
Two strokes are still very much here, but the demand is less because people don't actively buy them.
https://www.christini.com/bikes/christini-awd-300
This one is carb but EFI is now common place for KTM, Husky and the like!
If you haven't checked out Cristini's AWD then go take a look
Sick as.
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Mine own creation!...
It looks super bright (& a bit white) in the pic (or just ‘washed out), or it did in the original! but there is a reflector lense from one of those cheap stick on reflectors bonded over the red led. It’s actually no brighter than the tail light and kinda mellow. Beats carrying a spare bulb on long night rides...
Got it wired in with the front led spots...
I call them dog lites
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Blown Again!
Above is my new Athena gasket. I should of checked it closer before fitting. I didn’t see the scratch cause it was black with the coating. So this time it’s on me (again!!
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You can see the leak path as a thin black line. The wetness in the head isn’t coolant, it’s unburnt oil (after a 70 mile ride!) Funny thing is the bike ran better after the head blew! The revs were crisp on pickup and really well ‘defined’. The rich mixture is another ongoing issue.
This is the plug after the same journey.
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@spookdog that is detonation/pre ignition damage! My dt was running 225psi compression before I lowered it and that suffered no detonation. Normally it's down to a lean mixture.
What heat range spark plug are you running?
Also heard of excess carbon build up causing detonation. -
@spookdog I really like this, that blue looks gorgeous
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@edfrearson Endurance blue is definitely a favourite of mine.
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Wasn’t my first choice! I also have every plastic panel (& tank) in mid/flat black.
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There’s a thread somewhere that has the volume of 3mb & 3bn heads, even has the volume of the dome on (a Makita, done it again!) Mitaka! piston iirc. I can’t find it for looking. Can anyone please help?...
I did a fluid test on the 3mb head I have fitted and it was more than my spare 3bn head! So I really need 3rd party measures...
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Why am I only now hearing about o~ring heads! How long has this been viable tech?...
Am I missing out on anything else? Backwards compatible airflow metred injector inlets that run off of a simple lambda probe in the exhaust?! Perfect mixture all the time?!...Ahhhhh 🤯
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Apologies if this is a daft question as I'm late to the party, but if you're blowing head gaskets have you checked that the head and the cylinder surfaces are perfectly flat?
Could be an opportunity to take it off, remove the studs and lap them both flat again on a sheet of glass (or engineers table) to be 100%
Ignore me if you've already checked this issue
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@nottsbiker
No daft questions bud. I haven’t recorded all my nightmares. But yeah, I’ve removed the studs and cleaned , checked and lapped. The second and third time the head blew are down to me, once using a gasket that had already been fitted, again when I used a copper gasket without fully understanding the process and not using spray sealant. The final time there was a scratch in the gasket that I didn’t expect or spot.I’ve fitted another new Athena gasket and torqued it properly. I’ve fitted a newly lapped 3bn head that’s tip top condition, and weirdly higher compression (12.5~13ml) than the 3mb I was using (14ml)...
The gasket blowing is only 1 issue I’m having. I have a black sooty plug, bogging down over 1/2 throttle and a nasty bog 1/4 throttle where the needle valve kicks in, that has been happening since I first got the bike. Oh and unburned oil in the chamber/ around plug. I’ve no idea what previous owners did to the carb. It was running on a 180 main jet though...
Every time I get somewhere another problem kicks in...New Athena gasket torqued properly, I’ve disconnected the oil pump and gone premix. Rejetted the carb to standard and am going to take it from there. Square one again 🥴
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Best I’ve had! After 15 mile test run...
Same plug, different light...
Was revving ‘quite’ cleanly up to 9000rpm on 1/2~3/4 throttle. Just a little snaggle @ 1/4 throttle...
updated ran the engine up to temp for 15 mins on tickover and the plug was black and wet. I’m @ 1 & 1/2 turns on the airscrew. I will try up to 2 turns, then maybe go down to a .20 pilot jet. I have some genuine Mikuni ones now. The cheap fleabay ones are worse than a joke. I brought 10 varying from .10 upwards and they were all the same. Even though they were stamped
