125-200cc Uptite 167

Okay, I’m starting to put it together.

The WR graph is relative to a fixed starting point and the CR graph is absolute.

5 degrees to ease starting. The CR definitely starts easier than the WR, which demands a more aggressive kick.

The 28 degrees makes sense with the PV, I should have known that one. I see it tapers off right away though. It may work better if it hung in there, or even went to 24 degrees at 2K then increased linearly to 28 or 30 at the point where the PV opens, then let off quickly to about 23 until 9K

The reduction beginning at 9K makes sense in light of this:

It’s a trade-off. The higher temperature allows the expansion to tune at higher frequencies due to lower density and heat of the exhaust gases. It does have less time to burn in the cylinder, but that is more than offset by the better exhaust scavenging. To bad someone could not design a pipe that had variable tuning. That might help get the best of both worlds. In any case, some gains might be made in this region to suit riding style or type of event.

This:

Only comes into effect because the exhaust is not working well any more. It’s a symptom rather than the real problem. If the exhaust tuned better at high RPM, there would be little in the way of pumping loss. Retarding the ignition allows the pipe to tune better, as above.

Now it all makes more sense, and I realize that I should have been able to figure this out. Just need to get my head out of my ass and think.

Thanks for your input everyone!

It makes sense to me that the increase in pressure (timing advance) at high RPM would cause more resistance (pressure) during the compression stroke hampering high RPM power?

I think of it this way, at lower RPM and 28 degrees of advance, the pressure has much more time to build and slow the piston during compression. So this effect is there, but even more so at lower and mid RPMs than at high RPM. The difference is that in the meat of the 'pipe' the scavenging is working and providing the offsetting benefit of a much larger fuel/air charge. At higher RPM, you still have the pressure build-up (less of it actually, because it has less time to build), but you do not have the pipe working as hard to offset the effects. Everything is a trade off.

Another way to look at it is, at a given amount of advance, the pressure problem will drop off linearly, but the pipe will drop off much faster. Retarding the ignition reduces the pressure and increases the pipe tuning. Even though complete burn no longer occurs, the benefits outweigh the costs.

So what happened to the kings of the stroker smokers? You guys must be snowed in?

15 degrees and snowing. Tomorrow night it will be -5 F. Didn't even get below zero all last winter. We are supposed to get another 6" by tomorrow already 6-8" on the valley floor.

Ditto... got 3 to 6 coming tonight . I will be up early shoveling the driveway

Looks like you guys need to adapt some snowblowerrs to them 167's!

Keep the snow up there guys!

It does in all engines not just 2 strokes. A common practice in drag race engines is to give full spark advance early and then at high rpm retard the spark 2 to 6 degrees for peak high rpm horsepower. With electronic modules controlling spark curve there is no reason not to do this as you get the best of both worlds. The big advance in the mid-range allows more fuel to be burned making more on the bottom then under an extreme load in high gear the advance is dropped back so it is not holding back the engine under the faster burning high pressure high load combustion charge. This modification will commonly net a 5 mph increase high gear.

Makes sense. Not preciesley the same thing that is happeneing in the 2T over the entire range, but it should be pretty close in the mid to high transition. As the cam (or pipe on the 2T) begins to tune, there is more charge in the cylinder = more pressure = faster burn = less lead time. Mind you, there is naturally less time due to higher piston speed, but the pressure must build even quicker. It also makes sense that the 4T would not need as much retard as the 2T right on top.

i aint really into motor mods for a bunch of reasons, esp porting. but i talked to george on this 167 kit and it kinda whet my appetite. there no replacement for displacement.

i shouldda asked him if itll work on the 09 WR cyl...ooops. if it does and my 125 ever poofs...

ooooooo- grunty! mrrrwop!

I just got a JD ignition dual map controller from FBF. This is a short clip of my first run with the ignition on my WR 167. Elevation is 4000', 13x49 gearing and 110x100 18 rear. I was really interested in response and roll on in 6th. The one map is much more linear and softer than the other map. It doesn't sound like it but I could definitely feel it. Remember this is with an EFM auto clutch and at no time from starting to stopping did I use the clutch and this is typical of 99% of my riding.

http://www.youtube.com/user/wallybeanmt#p/a/u/0/jaeOauPS5w0

I did this test with the stock spring and silver spring combo. I am going to do some more testing with other springs as I haven't changed in a while or since I got the cr ignition mounted. I talked to Mr. Ferracci this afternoon and when I have some time I am going to send him the controller back. He has a map that will be a better match for the big bore kit in tight conditions and will maximize low end/mid-range as well as retaining an overall good conditions map. Once you buy the controller map changes are free just include shipping. The Husky community is so awsome when you can get on the phone and call the legends like Eraldo and George Erl and they spend as much time as you need to get your questions answered.

Have you ever given the thought of becoming a test pilot for the Husky factory? This is great work Walt! Thanx for being a great Pioneer and King of the Stroker Smokers! Really looks like you can customize this program to your riding style.

PS: Thanx for sending us the snow that is coming down this way tonight!

Darin

Walt, very cool indeed, that 167 sounds mean!

2 questions on the swap.

You need to have a CR coil correct? I buttoned mine up with the WR coil and there was no spark.

How did you set the timing? There is no marking for the CR stator in my WR. Based on the manual, it appears that it is just centered on that protrusion, or?

Thanks
Adam

Wally, Are you putting this on with the stock WR ignition ? Just wondering if it is worth the effort if it will work with stock ignition. I am not interested in putting on a CR ignition.
Dwight

Adam,

It takes the CR coil. At least that is why I think they are different. I haven't tried to use the WR coil. The husky repair manual lists how you create that mark. You will need their special tool which is just an indicator you attach when you find top dead center with a dial gage.

Dwight,

You would need the CR stator to make it work. The difference will be that where mine now pulls consistently from 3000 rpm on up until the power valves open and it rips, the wr has a soft area in the 1000 rpm below the power valve opening where it doesn't pull as hard. This is pretty well minimized with the 167 but it is still there. The thing about the 167 is it will pull through this area without the need for clutching or shifting unless you are on a serious incline.

The positive thing about the future WR's is they will get the same Kokusan (sp.) as the CR just with the bigger flywheel and lighting coils. I don't think they used it on the 2011's like yours but I might be wrong. I haven't seen the parts book for the 2011's yet. If it does then you can hook right up using the old wiring harness (~$25). So I expect all the future WR's to offer the dual switch and programmability.

More to come soon,

Walt (Dr. Huskenstein),

What is your guess, of what your bike is maxing out on (RPM wise), before the powerband flattens or tapers off?

George just did a bore only and fitted a bigger piston, correct? I can see he cut your powervalves for the new bore. But the piston was a shade taller and that is the reasoning behind the spacer, correct? Did you have to do any case mods or stroke the crank as well?

How do you think your bike would run against a 250 4st on a straight?

Darin,

I don't have a feel for what the actual peak rpm is, the Trail Tech tach doesn't give the most accurated readings and will actually hit about 10K and then go backwards as you climb more? It is just using a wire wrapped around the spark plug wire and I am sure there are issues with that connection. At some point I am going to run it on a dyno. I want to do a series with comparisons between the three motors 125, 144, and 167. I just have to do it. There is a dyno in Missoula I can use but they only have access a couple of days per week and the cost is a little bit of an issue with Christmas time and wanting to go south for two weeks. I will probably do this in late January when I have time and will be going stir crazy.

George's kit requires no mods on your part other than adjusting your jetting accordingly. The spacer is to give you clearance with the stock head and the taller piston. It is not exactly bolt and go as it takes a number of hours of break in time. I have ~ 10 hours on my top end before I was willing to rev it to the limit without worries. As far as comparing it to a 250F that is going to be hard to do. They just have such different characters. The little time I have ridden with a rider of equivalent talent who is also on a 250F, I found it pulled better bottom to early mid. The 250F(modded KTM) pulled better in the meat of the mid-range. The 167 has the edge on top until the revs quit when the 250F will pull another 2-3K more(just shift). I can't compare it to my one buddy who has a very nice running KTM because he is just a lot better than I am. The one time I got to spend some time following someone of equal talent(40#'s lighter than me) is when I make these observations. It was obvious where in his power band he was and how much throttle he was using while I was right behind him pushing. Bottom to early mid I had to be careful or I would ass end him. Now that I have the CR ignition I am not sure but that I would be able to stay there anywhere in the power band. Pretty good matchup with the weight/rotating mass consideration going to the 2T. In a flat out drag it is going to be hard to top the 250F just because of the breadth of the power band and not having to shift as often.

More to come later.

It's just fun to see what these guys can come up with.....thats why for me anyway LOL.

Walt,

Can't wait to see the comparison of all 3 (125,144,167). Keep up the great work! I think your doing a great job!