125-200cc WR 125 better, but.....

[wallybean]

Guys,

I just got back from my first real ride on my WR125. I have the jetting dialed and the low end to mid-range is surprisingly strong. OBTW this is a great bike. The problem comes in that there is a 1000-1500 rpm gap between the top of the mid-range pull and when the power valve starts to open. Once it starts to open it is immediately wide open without any progressive action. The rub is in the gap between when the bike really labors to pull enough rpms to open the pv and then katy bar the door we are under way. I haven't put a meter on it to read rpms but I am going to say that the pv first starts to open at about 8500 to 9000 rpm. This is counter to everything I have ever read about previous WR 125's and those of you with 09's that somehow have a progressively opening power valve.

Believe me if you rode my bike or Bob's or John's you would be very disatisfied with the performance. I don't want to make waves, I just want it to at least pull between the mid-range and the top end. I have years of jetting experience and I know what I am doing, it isn't jetting. I tried a PWK airstriker and it ran perfectly except for the dead spot. I do have to say that the TMXX is vastly superior to the previous TMX models. low speed metering is very adjustable and farely easy to get spot on.

Looking forward to any thoughts and hopefully a cure. The rest of the bike is so good, it would be a shame to have to work around a dead spot in the meat of the powerband from about 6500 to 8000 rpm.

Walt

 

[Motosportz]

I would like a handful of power valve springs to play with.

 

[WR BOB]

Guys I got my bike back Saturday and didn't have time to ride. Gerald swares it's right this time. He was very excited since this was his first upgrade kit/retune job. I'm going to make time to ride this weekend and will post a ride report.

WR Bob

 

[krieg]

Guys I got my bike back Saturday and didn't have time to ride. Gerald swares it's right this time. He was very excited since this was his first upgrade kit/retune job. I'm going to make time to ride this weekend and will post a ride report.

WR Bob

Bob, where are you planning to ride? Cody and I will be riding this weekend and I'd like to meet you if possible.

 

[HuskyDude]

I would like a handful of power valve springs to play with.

Boy Kelly, I bet you could solve a lot of problems with that little critter if you played with the springs.
I can feel my spring (P/V) opening, then my bike transforms into a rocket.
It would be interesting to see if with a little weaker spring the transformation would be a less abrupt and happen just a wee bit sooner. I know jetting plays a very big part in all this but I just feel the P/V just ain't perfect yet....maybe if and when we get the new expansion chamber it will help.

 

[wallybean]

Hey guys,

I finally got my springs yesterday evening. I started trying different combinations this afternoon. There were no springs that were readily available that exactly match the 1.1" stock spring length. All the springs I ordered were only 1". You can special order springs but I am sure the cost is triple. I first tried the stiffest spring that I had in this batch. It has an 18.65 Lb force to compress to fully open the pv compared to about 23 Lb's for the stocker. Dropped engagement about 1000 rpm's but engagement is abrupt like stock it just holds it's acceleration longer and I thought it was a tad hyper-active reacting. I then tried the weakest spring I had and added a spacer to bring the spring length dimensions to stock. This spring has a force to fully compress of only 12.15 lb's. Really transformed the power band. The bike pulls very strong and clean for at least 4000 rpms. I don't know why but the transition seems more progressive. It may be because the engagement is low enough in the rpm range ~ 6000 rpm that the power is below the peak efficiency of the porting in this cylinder and takes some rev's to reach the wild assed wheel spinning 125 on the pipe reaction. Don't get me wrong it is still pulling really hard when it initially opens, it is just more throttle controllable. I still have a jetting issue because it is running somewhat lean now when on the pipe. I don't have a 480 main but one is on order. I think when I get the new pipe it will somewhat make the transition even less abrupt by accentuating low/mid-range exhaust timing. All my testing is occurring at my property which is @3900' elevation.

Spring specifics:

Stock: 1.1" tall; 1.035" od; .83" id; .1" dia spring(spring material looks like music wire)

Current replacement: 1.0" tall; 0.975" od; .827" id; music wire .074" dia.

stiffest replacement: 1.0" tall; 1.1" od; 0.90" id; stainless steel

medium spring I haven't tried yet= same as stiffest stainless steel but instead of .1" dia. wire it has .85" dia. It is a little over a pound stiffer than the .074" dia. music wire spring.

Music wire springs are stiffer than stainless steel springs which allows you to really fine tune your application. There are other varieties of spring material but almost all of them have much larger load ratings.

I am not done yet because the jetting is still not perfect(the color of the plug is just to close to the edge), and I think the new pipe will change the motor characteristics again. I hope to get in a ride in the next week when I get the bigger main and will report back.

The latest update on the new pipe is that the pipe is in the states but FMF is building the Spark arrestor/silencer and hasn't finished final production.

Kelly,

Talked to a couple of guys that say that your Doma pipe is a large improvement over stock. Made significant gains over the stock pipe everywhere, just don't have one that you can plug into the new frame off the shelf. This isn't first hand information, just passing what I heard on.

Walt

 

[WR BOB]

Replacement Pipe Is In!


Just got an email from Gerald at Update who works 24/7. He has my replacement pipe in from the Husky Gods. I want have a chance to get it before Krieg and Cody school me Saturday at TNT. It had been on backorder since I bought the bike in April.

WR BOB

 

[Motosportz]

awesome info. Thanks.

Walt, how close do the dimensions need to be to fit in there? Tight or fudge a little?

- Riding the 2010 FE390 gave me renewed interest in getting the most out of my 125. I have ripped the suspension off and am sending it to Richard at House of Horsepower. I LOVE Les at LTR but Richard has been a long time friend, sells my dampers and asked me many times to do by suspension so I'm going to give him a shot. He does some pretty high end work and have been a suspension guy for a long time. His suspension shop is in Cannon Racecraft spring makers building. he says he has some crazy triple rate spring for the rear especially made for the unique issues with a 125. I guess getting plush on roots but stiff enough for jumps on a light bike takes some special methods. He is really going to do a lot. We will see.

The Doma is off an 04 and was not that hard to get to fit. Tweak here and there. The big down side is it covers the oil fill hole. I dump oil in the clutch cover I am also running a PC SA muffler. 125's are very sensitive to back pressure, muffler length and pipe dimensions. Right now I am pretty happy with the way mine runs.

I am going to order up some springs and try stuff though. I also might take it by a local 2 stroke Guru who does a lot for mini race teams. This motor should be right up his alley. He is big into this stuff and has a bunch of accumulated info he dumps into a database and ports off this info. I've heard from several people he gets good gains out of YZ125's so I am going to talk with him.

i got momentarily sidetracked with the amazing FE390 but riding it back to back with my bike i realized my bike is awesome too. With a little more power and excellent suspension I feel it is going to be one hell of a bike. We will see.

 

[MattR]

Walt,

I noticed you talking about spring preloads. This would only effect the point in which the PV first opens. You may want to consider spring rate too. The spring rate will effect the load increase during PV travel. My point is, you may have a higher preload spring, but the spring rate could be less... this would give a feeling of opening at a higher rpm initially with little control beyond that point. Whereas, a higher preload spring with higher spring rate would both change the initiation point and provide more control (stiffness) beyond that point. Just something to consider if you are ordering custom springs.

By the way, the material has more influence on the spring strength/fatigue resistance. The spring OD and wire diameter the most effect on spring rate (stiffness). The spring freelength, installed height, and spring rate then determine the spring preload.

Just some background on coil springs... I'm a suspension engineer who deals with springs all of the time.

EDIT:
Here's more design info that you will probably care to know about but glance over the compression spring section. You will see the formula for spring rate. You will notice how the wire diameter and body diameter have a large influence (both raised to the 3rd and 4th power).
http://www.centuryspring.com/pdfs/12-229.pdf

Also, I have bought small batches of coil springs from Century Spring (for various projects at my work). They have a huge selection of ready-made parts but can make anything you need. I have no affliation with them. I'm just passing along info to help a brother out.

 

[raisrx251]

Fill me in here, where are you guys ordering these power valve springs from?

 

[Motosportz]

Oh, here is another thought. When I installed my upgraded PV's I noticed they do not go very close to the piston when closed. There is a collar that it bottoms out on up at the linkage on top. I was really temped to machine the collars down some and let the PV drop slightly lower and closer to the piston. Anyone know what this might do? It would be easily reversible if it did not work.

 

[Norman Foley]

I got the updated OEM pipe and silencer today. Bottones installed it and I'm riding a Shane Watts school the next two days, so I'll report.

 

[Motosportz]

I got the updated OEM pipe and silencer today. Bottones installed it and I'm riding a Shane Watts school the next two days, so I'll report.

I'd be real interested in if there is a difference in performance or just a clearance upgrade. did Fran say if it looked dimensionally different?

 

[Coffee]

I got the updated OEM pipe and silencer today. Bottones installed it and I'm riding a Shane Watts school the next two days, so I'll report.

Nice!!! I was hoping the pipes would be coming in, I've been curious about their status.

Let us know is Shane learns anything from you

 

[wallybean]

Kelly,

There is a lot of room for different sized springs. The limiting ID is about .08", but this is only because of the washer on one side and the gear slot on the other. Both of these can be altered with no issues as far as using a smaller ID spring. Od is limited by the slot in the gear and the width of the washer on the other end. My 1.1" od spring fits easily but again a little bit of metal removal with a lathe would allow larger springs.

I bought my springs from an outlet for Century springs. This is very easy to do online. There are actually many companies that provide vast selections of many different types of compression springs. I tried to simplify the large amount of data on every spring from free length to fully compressed length to load rating which is a lb per inch measure to load at full compression to load at initial deflection. Each type of spring material has different characteristics as MattR pointed out as well as the effect of different heat and work treatments for each type of steel alloy. I spent 5 years in ME and not that I remember anything but the very basic from my metals classes 30+ years later and a completely different career the last 25+, it is still fun to experiment as a lay person. They have extremely competent people working as engineers at these companies that could easily develop exactly what you want from initial opening to the progressive qualities of the spring compression.

Ideally I would send my whole power valve govenor assembly to these folks and let them ship me back the exact variety of springs that I want. Give them the rpm's of the govenor and they can give us exactly what we want. You know as soon as the snow fly's I am going to do just that. What fun. If none of you have pulled out your PV govenor, you are in for a treat. It just doesn't get any easier than on the husky 125's. No need to pull the case, just remove your pipe, pull the power valve linkage cover off, disconnect the plastic accuater arm, unbolt the arm from the shaft coming off the govenor, pull the cover off the PV govenor and pull it out. All this takes maybe 5 minutes with the pipe springs being the biggest head ache.

Once again to echo MattR, these springs are not a hard to get item and with a little bit of input from the experts at these companies we can easily get a wide variety of springs to match what each individual wants for performance. I spent literally 30 minutes in the dead of the night looking and ordering just your very basic spring combinations on the web. Probably one of those instances where a small amount of knowledge gets me in trouble. But what the hey it is definitely far better than it was before and I am just getting started. I am also sure that I am re-inventing the wheel because there are many fine tuners that have been through all this before. I just like the journey and like tinkering with my toys.

Keep up all the thoughts and ideas,
Walt

"It is not the final destination that brings fulfillment, it is the journey and the associations we participate in along the way"

 

[ajaxauto]

Boy I sure hope for 2010 Husky continues to make a CR 125 because it seems you guys have to change a lot of stuff to make your Wr run like a CR .Plus the cost of the new bike plus all the parts and effor and lets not forget about the cost of a bigger gas tank makes me think One more year on my 2008 with no Husky Bucks is a cheaper way to go

 

[raisrx251]

As of last year a 2008 qualifies for 2010 contingency. I am not sure if they are doing that this year or not. Bike is good for 2 years in the money.

 

[krieg]

Just got an email from Gerald at Update who works 24/7. He has my replacement pipe in from the Husky Gods. I want have a chance to get it before Krieg and Cody school me Saturday at TNT. It had been on backorder since I bought the bike in April.

WR BOB

Trust me. There will be no schooling provided by me. I'm doing well to make it through a trail without falling. Cody, on the other hand... he schools me all the time!

 

[wallybean]

Ajax,

It is not that we want it to run like a "CR", it is just that we want it to run at all without a big fat bog in the middle of the powerband. The pipe, power valves, power valve govenor, carb, etc. are the same between the 09 CR and the 09 WR. The 09 WR has different jets but has the "CR" jets in the box. Other than that the only difference is the flywheel and ignition. The flywheel and ignition are one of the reasons I want the WR over the CR. So we probably don't need to be reminded several times that we are making a mistake by buying the WR because the CR is better. My guess is that when I am done the WR will be perfect for what I want and I didn't have to spend a lot of extra money to put lights, etc. on the CR to plate it here in Montana. The money I do spend on springs/jets is still less than having my coil re-wound and buying a lighting kit.

I don't mean to rant buy I am probably not quite as dumb as I look.

Walt

 

[ajaxauto]

Ajax,

It is not that we want it to run like a "CR", it is just that we want it to run at all without a big fat bog in the middle of the powerband. The pipe, power valves, power valve govenor, carb, etc. are the same between the 09 CR and the 09 WR. The 09 WR has different jets but has the "CR" jets in the box. Other than that the only difference is the flywheel and ignition. The flywheel and ignition are one of the reasons I want the WR over the CR. So we probably don't need to be reminded several times that we are making a mistake by buying the WR because the CR is better. My guess is that when I am done the WR will be perfect for what I want and I didn't have to spend a lot of extra money to put lights, etc. on the CR to plate it here in Montana. The money I do spend on springs/jets is still less than having my coil re-wound and buying a lighting kit.

I don't mean to rant buy I am probably not quite as dumb as I look.

Walt

I am just having fun with you thought i would just get you started
All in fun As for the lights to rewind my stock stator cost me 100 dollars It now puts out 35 watts a small 35 watt light is cheap but i went for a racing type led light which was much more
Keep up the testing as i will have to replace my CR soon and a WR looks like the only 125 husky will be importing
Plus it is about 115 degrees outside and to hot to ride so i am wishing i could ride
Later John