Dave B
Drag-strip hero
Posts: 240
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Post by Dave B on Jan 27, 2020 11:10:50 GMT 1
I made a compartment inside the seat hump (it's a FZR seat with the pillion bit filled in). It holds a bottle of oil with exactly enough oil for 10 litres of petrol, and the lid is held by Dzus clips. I use 32:1, because if necessary you can do the maths for any amount by halving. So if you need to add 8 litres, half of 8 is four (=2:1). Half of four is 2 (=4:1), Half of 2 is 1(=8:1), half of 1 is 0.5(=16:1), half of 0.5 is 0.125=(32:1).
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Post by muttsnuts on Jan 27, 2020 11:53:34 GMT 1
I have a brand new case with the extended cover and oil pump drive, but they are £325, hence most people avoid them due to the cost Money isn’t the problem, it’s just they don’t look trick like the genny side and I’d have to have it stripped and polished, but I may be stuck with that route. ah ok, yeah, see what you mean........
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Post by Tobyjugs on Jan 27, 2020 12:37:40 GMT 1
Here is the pictures for the oil bottle space. It wasn't made with that in mind it was just a handy bit of space. Hi Steve yes thats a good reason. What's that swingarm russpuss? Got any clearer pics of it? The swing arm is from a TZ
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Post by Tobyjugs on Jan 27, 2020 12:55:35 GMT 1
I use premix at 50:1 with Motul 800, jetting is correct for this mix I carry 3 x 100ml oil sample bottles under the duck tail, the oil sample bottles don't leak as they are designed to send, well, oil samples Each bottle is good for 5 litres of fuel, if its 4.8 litres 100ml still goes in As said above premix is not an exact science Yes I get complaints when the bike is smokey I prefer to call the blue smoke coming out the back as rust proofing for those bikes following This essentially what I do, but with a 2.5oz bottle. 2.5oz to a gallon is roughly 50:1. Best not to be messing with your oil ratio too much as this affects your jetting as well, and the diff between say 28:1 and 50:1 is actually quite alot. You may think more oil is "safer", but it really means you're getting only half as much fuel. Best practice is to pick an oil ratio and stick with it. Jet accordingly and all will be well. Yes this is noticeable. My carbs are adjusted at 28:1 when less oil is added the carburation becomes richer and i can feel it a little. The bike just becomes a little less responsive, but it's still quick.
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Post by arrow on Jan 27, 2020 13:33:18 GMT 1
With regards to jetting, we are spoilt these days with electronics, oxygen sensors and the like. A few years ago, I took my 250e out one day. That bike ran sweet, but this day it ran like a pig. That day it was 30° in the shade. Back in the day, I never had a clue why some days the lc was very much on song, or not so. I'm led to believe that racers sort the jetting out for 'that day'.
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Post by russpuss on Jan 27, 2020 13:48:45 GMT 1
Thanks for all the input chaps, Looks like I'm going to run with an oil pump as I don't trust myself not to. I'm going to see how much a 1 off billet cover will cost me against the option of a standard Mattoon modified one that has been stripped and polished with a polished oil/water cover.
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Post by reedpete on Jan 27, 2020 20:57:31 GMT 1
With regards to jetting, we are spoilt these days with electronics, oxygen sensors and the like. A few years ago, I took my 250e out one day. That bike ran sweet, but this day it ran like a pig. That day it was 30° in the shade. Back in the day, I never had a clue why some days the lc was very much on song, or not so. I'm led to believe that racers sort the jetting out for 'that day'. Yep, you needed a reference baseline for each circuit, then adjust accordingly for barometric pressure, temperature and humidity...
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Post by arrow on Jan 27, 2020 21:03:48 GMT 1
And there's a thing. They make quite a bit more power when it's cold and damp.
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Post by reedpete on Jan 27, 2020 21:06:56 GMT 1
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Post by arrow on Jan 27, 2020 21:09:59 GMT 1
That's a bit small for me to see. Could you email me a copy please? I find it interesting.
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Post by steven on Jan 27, 2020 21:15:51 GMT 1
With regards to jetting, we are spoilt these days with electronics, oxygen sensors and the like. A few years ago, I took my 250e out one day. That bike ran sweet, but this day it ran like a pig. That day it was 30° in the shade. Back in the day, I never had a clue why some days the lc was very much on song, or not so. I'm led to believe that racers sort the jetting out for 'that day'. Yep, you needed a reference baseline for each circuit, then adjust accordingly for barometric pressure, temperature and humidity... ....At the TT they go from sea level, then up on top of a mountain, then back down to sea level again, so barometric pressure will be different at sea level to on top of the mountain, bit of a nightmare to jet properly for that situation. I would imagine there was/is a bit of "gigery pokery" going on with jetting for the TT.
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Post by pdxjim on Jan 27, 2020 21:16:21 GMT 1
Messing about with your jetting for weather conditions just isn’t feasible for most riders.
Find a good medium (median?) jetting for average conditions and “jet it and forget it”.
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Post by steven on Jan 27, 2020 21:17:59 GMT 1
And there's a thing. They make quite a bit more power when it's cold and damp. ... just fit an intercooler... or to give it its official name, a charge air cooler. Be cool to see an LC with one of them fitted ! :-) Steven.
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Post by nobby62 on Jan 27, 2020 22:07:55 GMT 1
I made a compartment inside the seat hump (it's a FZR seat with the pillion bit filled in). It holds a bottle of oil with exactly enough oil for 10 litres of petrol, and the lid is held by Dzus clips. I use 32:1, because if necessary you can do the maths for any amount by halving. So if you need to add 8 litres, half of 8 is four (=2:1). Half of four is 2 (=4:1), Half of 2 is 1(=8:1), half of 1 is 0.5(=16:1), half of 0.5 is 0.125=(32:1). I’ve read this a few times ..... I can’t make any sense out of it.... 🤔🤔
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Post by Tobyjugs on Jan 27, 2020 22:50:11 GMT 1
I use my bike all year round and normally alter the jetting slightly for the the cold winter weather. This year i haven't had to do it.
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Post by donkeychomp on Jan 28, 2020 0:25:29 GMT 1
Cold and heat and sea levels are pretty important. My Mito came with a manual about what jetting to use in all those different temperatures and height. Seems like a bit of a faff but if you are racing...get the mechanics to do it!
Alex
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Post by reedpete on Jan 28, 2020 8:43:18 GMT 1
Cold and heat and sea levels are pretty important. My Mito came with a manual about what jetting to use in all those different temperatures and height. Seems like a bit of a faff but if you are racing...get the mechanics to do it! Alex The page I posted above is from the Mito manual 😁 The higher the BMEP of an engine the more it matters .....so we don’t need to worry about our stock RDs
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Post by arrow on Jan 28, 2020 9:03:49 GMT 1
Cold and heat and sea levels are pretty important. My Mito came with a manual about what jetting to use in all those different temperatures and height. Seems like a bit of a faff but if you are racing...get the mechanics to do it! Alex The page I posted above is from the Mito manual 😁 The higher the BMEP of an engine the more it matters .....so we don’t need to worry about our stock RDs Exactly right. I used to do a bit of radio control model plane flying. The engine mixture was set up for each flight (by ear), with basically an adjustable main jet. One of my favourite engines I had in a 43" wingspan Spitfire was only 4.07cc but 0.8bhp@18900rpm That's 197bhp/litre. Engine designers strove for years to try to achieve the magic 200bhp/litre figure for a reliable road bike. Does anyone know which bike got there first?
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Post by tony2stroke on Jan 28, 2020 10:37:35 GMT 1
I know the magical RGV250 came with 55 BHP standard in 1989, so that's 220 bhp per litre.
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Post by arrow on Jan 28, 2020 11:03:37 GMT 1
Right enough Tony, but something else was before that.
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Post by tony2stroke on Jan 28, 2020 12:07:10 GMT 1
Right enough Tony, but something else was before that. 1 more go! was it the TZ250
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Post by oldbritguy on Jan 28, 2020 12:43:00 GMT 1
The page I posted above is from the Mito manual 😁 The higher the BMEP of an engine the more it matters .....so we don’t need to worry about our stock RDs Exactly right. I used to do a bit of radio control model plane flying. The engine mixture was set up for each flight (by ear), with basically an adjustable main jet. One of my favourite engines I had in a 43" wingspan Spitfire was only 4.07cc but 0.8bhp@18900rpm That's 197bhp/litre. Engine designers strove for years to try to achieve the magic 200bhp/litre figure for a reliable road bike. Does anyone know which bike got there first? I am sure I read somewhere that Walter Kaaden managed this with one of his MZ 125 racers in the 1960s I know it sounds mental but without this man's genius, we would not have seen the Japanese development of the modern 2 strokes we all love. If you can find a copy (it is now out of print) read the story of Stealing Speed by Mat Oxley. Says it all John
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Post by arrow on Jan 28, 2020 13:07:35 GMT 1
Right enough Tony, but something else was before that. 1 more go! was it the TZ250 Correct. I think you meant to say TZR. Yamaha claim theTZR 250 was the first road bike to achieve this figure.
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Post by Tobyjugs on Jan 28, 2020 13:13:25 GMT 1
There's a group in Holland with a 50cc engine which makes 24pk it does make more sometimes but it's inconsistent
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Post by arrow on Jan 28, 2020 13:15:55 GMT 1
There's a group in Holland with a 50cc engine which makes 24pk it does make more sometimes but it's inconsistent Wow, the Stressss.....
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Post by Tobyjugs on Jan 28, 2020 13:19:39 GMT 1
There's a group in Holland with a 50cc engine which makes 24pk it does make more sometimes but it's inconsistent Wow, the Stressss..... They treat the project very serious. The bike arrives covered and once in the dyno room the door is shut and no one is allowed in except the owner of the dyno.
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Post by arrow on Jan 28, 2020 13:25:58 GMT 1
Good stuff.
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Post by headcoats on Jan 31, 2020 10:24:49 GMT 1
Those new generation fuel injected KTM 2 strokes with gizmos to deliver the 2 stroke oil are running at 80-1 according to the bumph !
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Post by headcoats on Jan 31, 2020 10:26:39 GMT 1
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Post by earthman on Jan 31, 2020 12:49:10 GMT 1
Those new generation fuel injected KTM 2 strokes with gizmos to deliver the 2 stroke oil are running at 80-1 according to the bumph ! That sounds extreme doesn't it? I know that there are very few, if any owners of those bikes who actually use them on the road but I'd like to know their longevity etc if you did..
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