"Instructions are just the manufacturers opinion on how to install it" Tim Taylor of "Tool Time"
“Saying what we think gives us a wider conversational range than saying what we know.” - Cullen Hightower
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when where what it ran all day Avalon rode after the restart and finished (was around third on the first lap from the back of the field but didn't like how it bucked and swayed in corners so drifted back further)
Avalon just refused to ride it again after that race
you will have to come up next year and see for yourself
"Instructions are just the manufacturers opinion on how to install it" Tim Taylor of "Tool Time"
“Saying what we think gives us a wider conversational range than saying what we know.” - Cullen Hightower
"I am a licenced motorcycle instructor, I agree with dangerousbastard, no point in repeating what he said."
"read what Steve says. He's right."
"What Steve said pretty much summed it up."
"I did axactly as you said and it worked...!!"
"Wow, Great advise there DB."
WTB: Hyosung bikes or going or not.
i dont think there is a dyno run on chart![]()
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No, Avilon fell and the race was re-started, on the restart she went from last to very close to the front in the first lap but drifted back as she battled with the bikes handling.
Thats when we knew for sure we were never going to be able to do it with the Suzuki GP chassis.....
oh the specifics!![]()
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Only because you and Squiggles have asked. I thought it was only that twit SS90 that was interested.
I can say that it didn't blow up and its first dyno test session, if not spectacular was at least encouraging.
Its the first cut and I would have liked to have completed some more development........
A lot of our recent work was inspired by some sensible and constructive posts earlier from Sonic_V they are worth another look….……
This is from memory, and remember Johns dyno only graphs rwhp against road speed so rpm has to be calculated.
The original engine with a std 24mm carb and an inlet duration of 225deg made 19+rwhp at 11,250 rpm.
The same engine was fitted with a barrel that has enlarged transfers and a reduced exhaust duration as suggested by SS90 and a 24mm venturi carb as suggested by Sonic_V which was fitted conventionally on the side, it made 21+rwhp at 9,500rpm. It ran best on a 130 main jet and was a strong runner at Taupo.
Same engine, same carb same 225deg inlet duration but with the plenum chamber, it was frighteningly fast up the drive on Taupo gearing but suffered badly from a flat spot below the power band at about 4-5k rpm.
Sonic_V in one of his early posts had suggested an inlet closing point of 60deg ATDC, for a duration of 205deg.
Same plenum engine, same carb but with 205deg inlet duration it still suffered from a lesser but significant flat spot below the power band at about 4-5k rpm.
Reducing the closing point to 45 then 35 degrees ATDC for a duration of 180 reduced the flat spot but it still made the bike unrideable in competition.
Increasing the inlet tract length inside the plenum by 35mm cured the flat spot and it was rideable on the track at Mt Wellington in the wet.
Now Dyno Time….
21+rwhp at 9,500 rpm from the conventional engine with 225 deg inlet duration Sonic_V venture carb SS90 barrel, Honda RS125 chamber and 130 main jet.
20+rwhp at 8,500 rpm from the same engine fitted with the plenum and 180deg inlet duration and it ran best on a 185 main jet.
Interestingly the plenum engine made much more hp below the power band, about 4-5hp every where and this extra low down grunt probably accounts for the wheel spin when giving it some big throttle during testing at Mt Welly.
Testing stopped when we realised that there may be a lubrication problem as most of the pre-mix oil was being left behind in the plenum. To do any more development I will have to build an auto lube motor to go with the plenum.
As the BMEP for 20rwhp at 8,500 is a whole lot better than for 21 at 9,500, it will be interesting to see where the plenum idea goes with more inlet duration and barrel/chamber mods as suggested by Sonic_V for max power at 10,500.
Team ESE are building some new chassis and I have taken the plenum off old Blue to use in the new bike.
So there you have it, encouraging but not spectacular….. "yet"………
Gentelmen do you want to place your bets?
Interesting.
The unusually large mainjet phenominon I have noticed when you "over carb" an engine.
For example.
Say you have a 125cc engine that produces 26PS with a 28mm carb, and a 138 mainjet, the same engine may well produce the same (peak) power (with flatspots in the midrange...some call it "resonance hole") using a (as an example 36mm carb), but requiring a 185 mainjet.
The same power (or less, or what ever) with a bigger carb, and massive mainjet?
That doesn't make sense at all.
Think about it at full throttle a 138 mainjet flows xxx liters per minute, a 185 significantly more.
No way that 185 mainjet is actually flowing what it can, therefore, why does the carb/engine combo require it, just run run somewhere close to cleanly?
In my experience, it comes down to signal strength.
In situations such as this, you can swap jets as much as you like, but there are resonance issues causing the problem, and big jets just mask it, not remedy it.
.
I have noticed this about you before, you obsess about things, it’s a bit disturbing.
Forget the blars, forget the main jet, all this has been covered before.
The blars were cured by changing the length of the inlet tract inside the plenum.
The larger jet is required because the air flow is all one way into the plenum.
There is now no problem with the blars and no stand off in front of the carb at any rev's.
You have seen the video……
You now have the dyno report and any more work on the plenum will have to wait until we have an auto lube motor and a good chassis to put it in.
Engines are not our main focus at the moment.
Now if you actually know, any tricks about converting an FZR250 chassis and suspension into a realy good bucket your input would be more welcome.
Otherwise we will have to ignore you as a time waster and mock you in the talk shit thread.......
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