Yesterday afternoon, I dropped the bowls on the carbs to see what jets I actually had installed versus what I though I remembered. Pilot jets - 40, main jet - 127.5. There was one shim installed under each of the needles. I I had looked through my posts from June I would've seen this information. On my test ride last week with the alternate air cleaner, there was a huge lag when the throttle was opened up past about half.
I went ahead and reinstalled the plastic fence post air cleaner aka as the Leftka 3 as it was developed by Leftka on the SovietSteeds Ural forum. I really needed to switch from the stock air cleaner due to the upcoming snowy season and the problems that I've had in the past with the filter clogging up with snow. I added an additional shim under the needles which will richen the mixture at mid-throttle. I also changed the main jet up to 130 from 127.5 which will richen the mixture at the upper half of throttle opening.
At my ride this morning to the University and College Coffeehouse, there was still a little lag at large throttle opening. I then turned off the switch on the PowerArc which enables the regular PowerArc timing curve from the high-load curve (retards the timing). This seemed to eliminate the lag.
Today was the monthly get together of the Airheads.org group at the Silver Gulch microbrewery in Fox, AK, located about ten miles north of Fairbanks. Not too large of a turnout today maybe a dozen or so but at least I wasn't the only rider out there. DaveW rode his nice bumblebee R100GS.
The Ural popped a couple of times on my way out of Fox so I may try changing the main jets to 132.5 tomorrow to see how it runs with a slightly richer jet.
At my ride this morning to the University and College Coffeehouse, there was still a little lag at large throttle opening. I then turned off the switch on the PowerArc which enables the regular PowerArc timing curve from the high-load curve (retards the timing). This seemed to eliminate the lag.
The Ural popped a couple of times on my way out of Fox so I may try changing the main jets to 132.5 tomorrow to see how it runs with a slightly richer jet.
Tuesday afternoon update - This morning I changed the main jets to 132.5 and it still felt "doggy" at full throttle. In other words acceleration actually improved at ¾ throttle compared to full throttle. Not right. I will try 135 tomorrow. It sure is nice to have the time to mess around with this...
ah the tinkering continues. :)
ReplyDeletere the p/a's switch for timing changes, never did see much change either ways.....on mine.
Yes, the tinkering continues. I was surprised to see that the switch did make a difference in the performance. When grounded, the "high load" setting, there was a sluggishness at full throttle. But when switched off the sluggishness almost disappeared. I'm still trying to get a handle on that and figure out how a change in ignition timing would do that.
Deletecould be my rig's switch wasn't installed/grounded correctly by raceway.
ReplyDeleteraceway said, use the "retard ignition" mode when on uphills
DeleteI had read where some add a vacuum activated switch to automatically retard the timing under low vacuum conditions.
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