Post by wayne on Jun 13, 2012 18:26:56 GMT -5
My good running red showed very rich initial running and overall too rich. I was reluctant to go too lean as I'm getting the impression that rotaries are tuned rich.
However, my red can be sluggish around 3800 rpm in top gear. You'll only feel it opening the throttle on a decent up slope and then it can be slow to respond. This is not the usual flat spot, hesitation, it's a power thing.
The dyno revealed a significant flat spot in power delivery that would approximate to this seat of the pants feeling.
So I kept the PMJ at stock 87.5 but dropped the SMJ by one size to a 177.5. This made a noticeable and significant difference to top gear acceleration where the bike had been previously sluggish. It was brisk to pull away, even up a hill. I rode around 380 klm like this.
But the bike didn't like it. No hesitation or anything like that, it just wasn't happy. It didn't like cruising at any steady rpm and was just "off" (although it did return nearly 46 mpIg on what was an average ride. Not fast but not a lazy ride (rained pretty much the whole way).
I'm going back to the stock 180. I'd rather a happy overrall bike for the minor inconvenience noted.
But I am noticing this across our five regular runners. The happy RE5's are the overall rich runners no matter what the stoichiometrics say. And note that the two best runners showed rich on the dyno using stock 87.5/180 jets. The M/A hybrid bike in our group can be tuned hesitation free but is just an unhappy runner. On the dyno and with the big PMJ it was the second leanest of the five tested RE's (I didn't put this chart up).
Similarly I recently fixed the hesitation in my A model and returned to an early spec stock 90 jet. No hesitation whatsoever but a cranky unhappy bike. This bike was the leanest runner by far and even lean by four stroke standards. I put in a 95 jet and it became a much nicer bike to ride (before fixing the hesitation it needed a minimum of a 100 jet to run hesitation free). I am going to also up the SMJ to 185 only to return the temperatures to the left side of the gauge middle mark.
Whether the whole fuel/air thing is correct or not, it seems that the leaner the bike and independent of hesitations, the crankier it is.
However, my red can be sluggish around 3800 rpm in top gear. You'll only feel it opening the throttle on a decent up slope and then it can be slow to respond. This is not the usual flat spot, hesitation, it's a power thing.
The dyno revealed a significant flat spot in power delivery that would approximate to this seat of the pants feeling.
So I kept the PMJ at stock 87.5 but dropped the SMJ by one size to a 177.5. This made a noticeable and significant difference to top gear acceleration where the bike had been previously sluggish. It was brisk to pull away, even up a hill. I rode around 380 klm like this.
But the bike didn't like it. No hesitation or anything like that, it just wasn't happy. It didn't like cruising at any steady rpm and was just "off" (although it did return nearly 46 mpIg on what was an average ride. Not fast but not a lazy ride (rained pretty much the whole way).
I'm going back to the stock 180. I'd rather a happy overrall bike for the minor inconvenience noted.
But I am noticing this across our five regular runners. The happy RE5's are the overall rich runners no matter what the stoichiometrics say. And note that the two best runners showed rich on the dyno using stock 87.5/180 jets. The M/A hybrid bike in our group can be tuned hesitation free but is just an unhappy runner. On the dyno and with the big PMJ it was the second leanest of the five tested RE's (I didn't put this chart up).
Similarly I recently fixed the hesitation in my A model and returned to an early spec stock 90 jet. No hesitation whatsoever but a cranky unhappy bike. This bike was the leanest runner by far and even lean by four stroke standards. I put in a 95 jet and it became a much nicer bike to ride (before fixing the hesitation it needed a minimum of a 100 jet to run hesitation free). I am going to also up the SMJ to 185 only to return the temperatures to the left side of the gauge middle mark.
Whether the whole fuel/air thing is correct or not, it seems that the leaner the bike and independent of hesitations, the crankier it is.