Dead Spot About 3000 RPM Under Light Load

[rww]

Did you pull the canister........leave a vacuum line open...maybe.... Has anyone looked to see if the throttle body has a air bleed port/screw to set the idle co......a little to much opening could be the variable on the bikes...

 

[Ignaciob]

Did you pull the canister........leave a vacuum line open...maybe....

For the third time....yes (but did this before the canisterectomy) and no. Posted about in the very first post, confirmed in #3, and reaffirmed now in #22.

 

[Ignaciob]

Has anyone looked to see if the throttle body has a air bleed port/screw to set the idle co......a little to much opening could be the variable on the bikes...

I can't see an idle screw...let alone very much of the TB at all. If there's a set screw in there--it's virtually impossible to get to.

 

[Delnari]

I too experience what has been described here when I first rode my bike, stock. Just before the 600 mile oil change I removed the canister, left the vent hose open, and installed the PCV with a map from another member (he tune the original map from dynoject with the auto tune module for better AFR). After those changes I have not hit the hesitation or flat spot with 970 miles on the odometer now. Not to say it won't come back, but for now it runs perfect with steady idle and starts up in 1-2 seconds at most when cold. Will update as I get more miles on it to let everyone know if this changes.

I did drown my baby recently, see other posting, and hydro-lock the engine. After 30 minutes I was able to free up the engine and has been running well without issue. I do not recommend it though

 

[DanD]

I just got back from a 3800+ mile trip on my Strada and the hesitation referred to in this thread started becoming noticeable at about 2800 miles and got progressively worse, as in the hesitation became more pronounced and its occurrence more common.

On the street I just don't ride under 3700 RPM without the clutch and in the dirt low speed work (10-15 MPH) is always clutched with higher RPMs. A bit hard on the clutch but mine does have a nice wide engagement. ;-) Ridden this way I find the "stumble" doesn't appear too often and it just becomes a slight annoyance. BTW, my bike is stock, no engine mods and all services are complete.

I should add that the 2800 miles mark is also when I noticed that the engine was making more speed at the same RPM in fifth. I went from 71 MPH to 75 MPH. I figured the rings are seating and everything is loosening up. The low RPM issues may just be from the higher state of tune of this motor.

 

[Leo Fisher]

This morning, the bike seemed to perform a bit better so I shall give it a few more hundred miles before condemning it! It's a fun little bike but trying to get away smoothly from a stop is nearly impossible unless you launch it ;-)

 

[bikehunter]

Oh for F*%S sake its week mixture, for 20 bucks its worth putting in the Eruption sensor and increasing the mixture by 6% and having a blast****************************************!

 

[Trapperj]

I have mentioned this in another thread...but thought I need to say again. I now have 10k miles on my Strada. I had the B/P first and then tried another gizmo "IICE air" it lowered the IAT temp but not as much as the B/P. with the IICE air after a few hundred miles it was kinda like the bike re-adapted to its previous lean condition and back came the dead spot. I switched it back to the BP which lowers my IAT 40 degrees. I also took off the charcoal canister. Few thousand miles now without a stall...hardly a stumble. It's also worth noting here that the IICE air works better on my R1200 GS than the B/P..but the TR seems to really like the original BP. As always YMMV.,!

 

[run-it]

OP:

5,000 miles on my Strada. For the past 2000 miles I've notice a dead spot about 3000-3500 RPM--mostly when I'm cruising at a steady throttle position on surface streets in the 30-40 mph range. I don't notice it at higher RPM, higher speeds, or higher loads.

I added a Booster plug at about the 1,000 mile mark and didn't notice this phenomenon until about 2,000 miles later.

The OP has a BP already so trying another 20C offset spoofer like The Eruption is unlikely to solve the problem. They're designed to do the same thing, the Eruption shines b/c it's so simple & more accurate especially at temperature extremes, but if the BP is showing 20C (36F) lower displayed temp (or there about) - it's working.

Spoofers only affect the open loop portion of the FI map on these bikes, steady state throttle is closed loop, the lambda sensor is in play at that time. As a test you could try unplugging the lambda sensor, the bike should run OK, it should just stay in open loop map, you can run it to see if there's any difference.

 

[rww]

As a side note I run the WK on cold setting and have 0 trouble. I am building a Eruption to compare to. When I pull the motor to adjust the valves I am going to look at the Throttle body to see if there is a air bleed screw. I know from experience that valves out of adjustment ( too tight) will make a motor do all kinds of crazy stuff that will drive you nuts. As for my bike it runs like a scalded cat, pulls steady from 2K and does not like to be cold...I am in the zone so I just check-record all the settings as I pull maintenance......don't want to muck it up

 

[run-it]

This morning, the bike seemed to perform a bit better so I shall give it a few more hundred miles before condemning it! It's a fun little bike but trying to get away smoothly from a stop is nearly impossible unless you launch it ;-)

If you don't have one, you'll almost surely benefit from using a spoofer. If you have hiccups or stalls when opening or closing the throttle a spoofer will likely solve that. The Eruption works great with these bikes & Dan has offered to make them at cost! (See The Eruption thread)

 

[NorthnTerraTory]

OP:


The OP has a BP already so trying another 20C offset spoofer like The Eruption is unlikely to solve the problem. They're designed to do the same thing, the Eruption shines b/c it's so simple & more accurate especially at temperature extremes, but if the BP is showing 20C (36F) lower displayed temp (or there about) - it's working.

Spoofers only affect the open loop portion of the FI map on these bikes, steady state throttle is closed loop, the lambda sensor is in play at that time. As a test you could try unplugging the lambda sensor, the bike should run OK, it should just stay in open loop map, you can run it to see if there's any difference.

Where is the lambda sensor?

 

[Ignaciob]

Where is the lambda sensor?

That plug in thing with a wire off it in the exhaust pipe under your left shin. It's particularly obvious on this particular bike.

 

[mag00]

That plug in thing with a wire off it in the exhaust pipe under your left shin. It's particularly obvious on this particular bike.

For that matter, has anybody tried a different o2 for the offset correction? Do all o2 put out the same readings?

Seems like a better alternative than spoofing the IAT, as the computer seems to correct to the lean condition with time. If the o2 is saying it is lean, (by spoofing o2) would you not get the desired result?

 

[run-it]

For that matter, has anybody tried a different o2 for the offset correction? Do all o2 put out the same readings?

Seems like a better alternative than spoofing the IAT, as the computer seems to correct to the lean condition with time. If the o2 is saying it is lean, (by spoofing o2) would you not get the desired result?

If you spoof the O2 / Lambda sensor it will be a different map that's affected than the spoofers we use.

O2 / Lambda sensor = closed loop map - steady state throttle
IAT = open loop map - varying throttle

Does the ecu go lean again at some point after a spoofer has been installed? That hasn't been the case for me, not even partially as best I can tell though it wouldn't be impossible.

If you unplug the Lambda sensor the ecu should default to open loop only operation, so now you'll get to try a different map in the otherwise closed loop realm.

 

[mag00]

I guess I will learn about the function of the o2 sensor.

Sensor output ranges from 0.2 volts (lean) to 0.8 volts (rich). A perfectly balanced or "stoichiometric" fuel mixture of 14.7 parts of air to 1 part of fuel gives an average reading of around 0.45 volts.

Observing the sensor’s waveform on a scope is a good way to see whether or not it is slowing down with age. If the sensor becomes sluggish, it can create hesitation problems during sudden acceleration. http://www.picoauto.com/applications/lambda-sensor.html

Seems like looking into the sensor mod, might provide a better solution.

My dyno run shows my bike going rich at just under 5k rpm. If I spoof to get rich on low, it will get richer on the higher rpm also.

If we replace the sensor to one with a narrow band, I think the lean low, and fat high could be remedied.

For argument, let's use the voltage curve above as the stock TR650 specs. If a lean is .2 volts, and fat is .8 volts, we might get a remedy with a .3-.7 volt range sensor. Fattening up the low end, and leaning the top end.

Since this is my first look into this, more information and discussion could benefit the TR owners.

My dyno guy said if I lean out my bike, I can gain 4-5 hp on the top. And get better mileage.

I also read about two different types of sensors, titania and zirconia, and have no idea why or what the difference is.

Any reasons why or why not this would work?

 

[spiderman]

Damn, this discussion has become way too technical for me. I have no idea what y'all are talking about. I just know that after I installed a BP the bike ran great for a long time then reverted to it's old self. Sure hope you smart folks get this figured out and tell me what I need to do to permanently fix this irritating problem.

 

[nev..]

Damn, this discussion has become way too technical for me. I have no idea what y'all are talking about. I just know that after I installed a BP the bike ran great for a long time then reverted to it's old self. Sure hope you smart folks get this figured out and tell me what I need to do to permanently fix this irritating problem.

Just for the sake of a properly controlled analysis, spiderman, have you removed the BP to see how the bike runs using the stock temperature sensor? Just thinking about the possiblities... if you rate the way the bike runs in stock form somewhere on a scale from 0 to 10, I would say mine ran as a 7 for instance, because it was prone to stalling at low revs at low throttle openings. Adding the BP increased the rating from 7 to a point where the bike was no longer prone to stalling. Lets call that a 9. Now, you think your bike with the BP is back down to a 7. The question which really needs to be answered (but doesn't appear to have been addressed in this thread), is, without the BP, is the bike running like a 7, or is it even worse, say a 4 or 5. Prone to stalling even and flat spots in the accelleration even worse even than when it was new. Possible that the bike needs some alternative attention.. a symptom of valves tightening up a bit ? Air filter due for a change?

 

[Craig Hashey]

I don't ride where starting fires will be a problem so for kicks and grins I pulled the spark arrestors from the bike yesterday and was surprised to find this morning on the way to work that the flat spot was almost completely gone. Also since day one the bike had a vibration that kicked in right at 75 mph like clockwork. So much so I didn't have to look at the speedo, I'd just know I was at 75 because of the vibration. This too was not there for the first time this morning. I intentionally rode between 3000 and 3500 rpm and at 75 over the 35 mile commute and was quite pleased. I will try it again this afternoon when the temp is supposed to be in the 80's and see if there is any difference.

 

[Craig Hashey]

Same result on the way home.