As you all know, Coffee (Dean) passed away a couple of years ago. I am Dean's ex-wife's husband and happen to have spent my career in tech. Over the years, I occasionally helped Dean with various tech issues.
When he passed, I worked with his kids to gather the necessary credentials to keep this site running. Since then (and for however long they worked with Coffee), Woodschick and Dirtdame have been maintaining the site and covering the costs. Without their hard work and financial support, CafeHusky would have been lost.
Over the past couple of weeks, I’ve been working to migrate the site to a free cloud compute instance so that Woodschick and Dirtdame no longer have to fund it. At the same time, I’ve updated the site to a current version of XenForo (the discussion software it runs on). The previous version was outdated and no longer supported.
Unfortunately, the new software version doesn’t support importing the old site’s styles, so for now, you’ll see the XenForo default style. This may change over time.
Coffee didn’t document the work he did on the site, so I’ve been digging through the old setup to understand how everything was running. There may still be things I’ve missed. One known issue is that email functionality is not yet working on the new site, but I hope to resolve this over time.
Thanks for your patience and support!
Yep the rod arrived yesterday and was setup within 10 minutesdid that rod get there already?!![]()
If it's detonation from crap fuel a couple gallons of AV gas or race fuel will tell you and then you can either buy better fuel or possibly get the cyl head re-cut for the crap fuel that you are using. There is a lot to squish band on a 2 stroke, I think Walt hinted that direction. You have tried most of the least expensive suggestions except fuel. You will have to tune it a bit with the good fuel to know if it solved your problem but at least you would know. Detonation is more likely in a lean situation but it can still happen with a rich condition and retarded timing if the compression is greater then the fuel can handle. This situation (high compression with crap fuel) killed about every 1960s muscle car engine that tried running on the crap fuel in the mid to late 1990s in the USA.
what settings did you try the rod at?
Solid advice, I went out today and screwed the PJ in to 1/2 turn out and it was immediately better by miles! Gave me a little lift for sure anyway so thanks for that.Harley with the MS3 you can close the pj right down to a 1/4 to 1/2 turn so dont be affaid to go leaner .
Is that lectron fitted with the short pj tube ? as the long one is not really suited to ms3 as it starts to come into use way to early.
PS If al else fails pop the carb into the post to me and I will set it up on a 125 and post the thing back to you.
I have heard of the squish band shape causing problems in cases where piston dome shape is changed or if someone has modified the head for max power with race fuel and then they switch back to pump gas. The width and shape of the squish band makes a big difference. Older GasGas bikes have a stepped head with a domed piston and some people use the GasGas piston to up the performance by putting it in an engine that a flat top piston used to go... or the opposite and replace the dome with a flat top but either way usually requires machining the squish band. I only mention this because when you buy a used bike you really have no idea what has been done by previous owners.This is indeed something I have been considering, I'm looking into where I could get better fuel though. I was thinking about trying 98 octane but I'm almost sure all you can get around here is 95. Avgas could be a possibility, theres an Airport quite local to me but I'd need to make some calls and figure out if I can just grab 5 litres in a can..
I was really thinking this was just an air leak lol.
As for the fuel, would an "octane booster" such as Silkolene Pro Boost be of any benefit?
The thing thats blowing my mind right now:
Yes the seal looked sketchy, yes I had some hand-cut gaskets on the intake side but even after everything I've done, the detonation hasn't changed. Surely changing the squish clearance would have made a change to the detonation?
On the other hand, I could be just plain dumb and missing something else!
All checked in the last rebuild (when it seized at the beginning of this thread). Piston, rings, pin and bearing done.Just another take on the situation.
is the sound you hear really the sound of detonation?
if you have leeway on you piston bearing or play in the piston pin in the piston you might have similar noises
Did you check if there is play in the con rod, piston pin to the con rod, and the piston pin to the piston?
Robert-Jan
Springs and o-ring are good and the exhaust is mounted well, but thanks for the suggestion!Just a thought how good is your exhaust sealed and are the springs fresh? I ask as i noticed a distinct banging sound as im flic flacking from side to side and im 73% sure its my exhaust moving in the cylinder outlet.
This was a while ago now, Im still certain I diddnt hear any detonation sound but if I remember correctly I did find that the crank seal on the stator side was leaking air. Replaced both seals, retuned as detailed above and have been using pistons from HTM Racing. The Makita pistons I was using were junk! Full top end on there now from HTM although I have a new bike now and so this bike doesnt get tortured as much now.Sorry, i must have skipped - what was the reason of detonation their?