StromTrooper banner

1 - 20 of 26 Posts

·
Registered
Joined
·
944 Posts
Discussion Starter #1 (Edited)
After doing a ton of research about doing the SV cam swap, I took the plunge. Since my '06 Wee has 45k miles, I decided to go with all new cams using Gen I and II after talking with Blair from SV Racing. It has taken me 4 afternoons to get to the point where I started the engine today. The engine spun for about 2 second and fired right up and settled into a nice idle at about 1,300rpm.....just like it did pre-swap and then began to gradually slow to 1,100rpm....which is perfectly normally for a fuel injected engine and how my engine behaved pre-swap. I haven't taken the bike out for a test ride yet as I didn't want to go thru putting everything together and only to find the engine wouldn't start or make a horrible noise and have to disassemble again. Using the idle screw, I raised the idle to about 1,500rpm's with a fan directed at the radiator while I used a stron flashlight to look for oil leaks. Found one at the front cylinder head cover where the crescent gaskets are located. Giving it a few strong raps with a plastic hammer stopped that leak. Once it hit 3 bars on the temp gauge, I started blipping the throttle and listening for any abnormal noise. Actually, the engine noise is slightly less that when I started. No ticking or clanking noises at all. Sounds like a showroom new bike. Before I began pulling the cams, I did a quick lash check and found that the exhausts were fine but the intakes were a little tight(both cylinders). I decided to keep the exhaust shims in place and go to the next thinnest shims on the intakes and see where that brought me. Worked perfectly. Now, on to the those damn cam chain tensioners. Dealing with these mechanisms caused me to spend at least a full 3 hours just removing/reinstalling these things. Both are very difficult to access....VERY! Here's a tip for dealing with the front cylinder tensioner install. First, put the tensioner body in place as best you can from the left side. Next, slide the spring up onto an extended length Allen wrench(3 or 4mm, don't remember which) and manuever the spring into the tensioner from above...taking your time like a surgeon. Once in place, use a long screwdriver to hold the spring in place while sliding the Allen wrench out of the the spring. Now, how to the get that washer in place? Use a long 3mm Allen wrench from above and place the long end into the the spring slightly, slide the washer onto the Allen wrench and let it slide down and it should go right into place. Did for me. Getting the bolt into place is next. You'll just have to use your fingers best as you can to get the threads started without crossthreading. No tip here, just do the best you can and don't crossthread.
 

·
Registered
Joined
·
944 Posts
Discussion Starter #3
Glad everything went well. What did you do for A/F management after the cam swap?
Power Commander III. Used the map recommended by Blair at SV Raving. I think his shop developed this particular map. Going to finally have a test ride tomorrow afternoon.
 

·
Registered
Joined
·
164 Posts
Sounds awesome, let us know how the results are when you get a test ride in.
 

·
Registered
Joined
·
944 Posts
Discussion Starter #7
Cam chain tensioners have to come out anytime you need to remove the cams. Cam removal is required to adjust valves.
Exactly! You can check the valve lash without touching the tensioners, but if the cams have to come out for a shim change, the tensioners have to come out and the plunger reset to it's slackest position. If you aren't familiar with how the auto-tensioners work, you won't know what I mean.

Took that ride today. Let the engine warm up to 2 bars and then rode off gently thru the rev range until I got 3 bars....which took a looooong time. First thing I noticed was the different exhaust note. I have an Akrapovic slip-on with the baffle removed and the stock engine had a rather raspy note during accel. The raspiness is now absent. The note is now a deeper bass sound almost as though the engine is now 100cc's larger in displacement. Running down the highway at 65mph(indicated) yields a much quieter exhaust note. I can't hear it anymore and I could hear it before the cam swap. I wear ear plugs religiously and now I can't hear the exhaust at all....or maybe just barely. Big difference there. Now to describe the performance change. First, at lower RPM's, the engine is softer and even smoother while trying to maintain an constant speed in 1st or 2nd gear. Pre-swap, the engine didn't like to run smooth at low RPM's in a low gear. It wasn't bad at all, but it tended to be finickey and just the slightest throttle change caused lurching, especially on level ground. Slight downhills was impossible to be smooth. Much less lurching now....probably due to lower bottom-end power so the engine works a little harder to maintan a steady RPM with a the slightest load. That is theory only. Now, to get to the real performance question. Does it make more power? ABSOLUTELY!! Power builds smoothly until about ....ohhh...I'd say around 5,500 RPM and from there under heavy throttle, the power builds very quickly and is notably stronger than stock. It's most noticeable at 6K RPM's which is where the power has a rather hard hit. Pre-swap, the engine would produce a muffled exhaust backfire upon decel sometimes, but doesn't do that now. It certainly appears that the Power Commander III fuel controller with the map provided by Blair is spot on. Blair claimed that this mod is one that will provide more power and make the Wee's engine run better all around. Sure seems that way so far. What I find so surprising are two things. The quieter exhaust note and the overall smoothness of the engine. Only one problem I have to report and it is my own fault. I installed new valve cover gaskets but don't have any sealant to use so I hoped for the best. Well, the front cylinder gasket is seeping at the crescent lobe area. I can't accept that so I will now be spending a few more hours to correct this. Cutting corners has now cost me much more work when I could be riding tomorrow when the weather will be as good as it gets.
 

·
Registered
Joined
·
944 Posts
Discussion Starter #8
Why did you removed those tensioners at the first place?

The tensioners only need to be removed IF the cams need to come out to change shims to bring the valve lash into spec. This engine uses a chim-under-bucket to lift the valves rather than a rocker style lifter. Rocker types are much easier to adjust and never require removal of the cams to adjust the valve lash. Why choose one over the over? Shim-under-buckets are direct acting lifters meaning that the cam lobes are situated directly over the valve stems and push down on the buckets that are on top of the valve stems with a precise thickness shim between the bucket and valve stem as the adjuster. The advantage to this design is that the engine can turn higher RPM's reliably. Honda's 450 motocrosser uses a combination of both designs. The intake is bucket and the exhaust is operated by a conventional rocker arm. It's redline is about 2k less than all the other brands. The advantage here is a compromise of compactness vs higher RPM's with less reciprocating weight.
 

·
Registered
Joined
·
944 Posts
Discussion Starter #10
Boit, do you think the smoothness is because your fuel management is better? I was thinking of getting a PC because the stock mixture is a little lean under 20% throttle for emissions.


Sent from Motorcycle.com Free App
Timely question. I've been in contact with Blair with info about this mod and he responded that that what I am experiencing is directly related to an improvement over the OEM system. It certainly appears that the R&R that Blair and his shop has done with dialing in the fueling map is a HUGE improvement over stock. Now that I think back about my test today, it seems to me that throttle response is now better. What I mean by that is that the throttle is not quite so sensitive as it was pre-swap. It's slightly....uuuhhmmm...softer..or gentler...not quite so abrupt. Before the swap, I had to be diligent about using the clutch to get back into power after slowing for a turn. Now, the transition from decel into acel is gentler.....but only in the lower RPM. Obviously, when the power is increased in the upper RPM's, the transition is more violent so clutch usage comes into play. I'd say that this cam swap makes the Wee's engine easier to operate smoothly. The bottom RPM range power is softer(less horsepower) so this makes it easier in stop'n go traffic without the lurching of the stock engine. Probably, what is happening with the stock engine is that it has to meet federal EPA emissions so it is not optimal. One of those unintended consequences of the government. As a last comment about this mod, if you want to do it, don't do it yourself unless you have a comprehensive knowledge of a 4-stroke, DOHC, and fuel injected engine....plus an extensive collection of tools....plus a ton of patience. Don't forget, you will be installing TWO intakes cams into an exhaust position and you MUST know how to time them correctly since the factory service manual does NOT cover such a mod. To access the rear cylinder cam tensioner, you will need some wobble 1/4" socket extensions. Lastly....PATIENCE!!!! and research. This was not my first mud wrestle so I knew what to expect. No matter how well you plan, there definitely WILL be problems so expect them.
 

·
Registered
Joined
·
944 Posts
Discussion Starter #11
Boit, do you think the smoothness is because your fuel management is better? I was thinking of getting a PC because the stock mixture is a little lean under 20% throttle for emissions.


Sent from Motorcycle.com Free App
Oh, BTW, you are on the right track even if you want to remain stock in your engine. The PC III has the capability to begin from the stock settings and then make small adjustments yourself in 250RPM increments based on throttle openings. Meaning, you make a quick adjustment via a push button and then take a test ride. You can even do this roadside. You are also correct about the lean settings....especially at low RPM's. Add a fee flowing exhaust and notice the exhaust backfire with the OEM settings. Optimal fuel mangement settings should result in a 'gurgling' sound followed by a series of small pops thru the exhaust. All you do is buy the PC III, download the stock map to your unit and then use the buttons on the unit to make the adjustments you want in 250RPM/Throttle position increments.
 

·
Registered
Joined
·
944 Posts
Discussion Starter #13
Today was so beautiful I had to take an extended ride in spite of the valve cover gaskets seeping oil. I rode 84 miles today and took a quick jaunt down the interstate where I could get up to a brief 80mph(indicated). What became immediately apparent was how the engine is now nearly devoid of vibration. Stone stock, I had some buzziness starting at about 70mph and up. Why this cam swap helped reduce vibration is not clear to me. It was in the low 70 degrees today and I noticed that as I cruised a back road at 50mph, the temp bars went from 3 to 2 a couple of times. I DID put fresh coolant with 4 ounces of Waterwetter since we are now heading into much warmer temps. Another comment about the change in the exhaust note, while riding today it occurred to me that the note is Ducati-esque sounding. Not saying it sounds like a Ducati, only that the note has moved in that direction. It is EXTREMELY pleasing to my ears. I got home and went to work getting the oil leak corrected. At least now, I and remove and re-install the radiator quickly vs the first time. The gasket sealant is now curing and will wait at least until late tomorrow before riding. I also happened upon this little tip in getting the air out of the cooling system. Fill the radiator up and wait a about 30 seconds for gravity to push out some of the air, re-fill and then place the palm of your hand over the fill neck and squeeze the hose (lower) rapidly. You can hear the air being forced to top by the squishing sound. Re-fill and repeat.
 

·
Registered
Joined
·
944 Posts
Discussion Starter #14
Good Report!

Just checked my valves yesterday @ 30,000 miles & everything is in spec, so did not have to adjust clearance & buttoned it back up.

May consider this mod next time I need to check valves.

Thanks,

Are you talking about the cam swap mod or the PC III? There is a long thread started by Blair when he used the same cams as I did. To save money, many owners are opting to move the stock intake cams over to the exhaust side and installing Gen 2 intake cams from the SV 650 in their place. Someone was kind enough to post a pic of where the timing marks will have to be on the cams when moved to the exhaust side. It was spot-on as I used that pic to make my indexing marks.The nice thing about doing this cam swap is that you don't sacrifice reliability since the SV and Wee engines are the same except the SV is tuned for better performance with the racier cams. Not only am I VERY VERY pleased with the much improved performance, but also by doing it all myself gave me a wealth of experience. If you intend on tackling this swap, I highly recommend you get the factory service manual. I could not have done the job without it.
 

·
Registered
Joined
·
874 Posts
When you get an idea of how much your fuel economy has been reduced, would you report back? That is, if you can stop twisting the throttle and giggling? I would expect a 5-8% drop based on looking at PC maps, and even more for you right now as you are probably getting on it harder than usual.


Sent from Motorcycle.com Free App
 

·
Registered
Joined
·
213 Posts
The tensioners only need to be removed IF the cams need to come out to change shims to bring the valve lash into spec. This engine uses a chim-under-bucket to lift the valves rather than a rocker style lifter. Rocker types are much easier to adjust and never require removal of the cams to adjust the valve lash. Why choose one over the over? Shim-under-buckets are direct acting lifters meaning that the cam lobes are situated directly over the valve stems and push down on the buckets that are on top of the valve stems with a precise thickness shim between the bucket and valve stem as the adjuster. The advantage to this design is that the engine can turn higher RPM's reliably. Honda's 450 motocrosser uses a combination of both designs. The intake is bucket and the exhaust is operated by a conventional rocker arm. It's redline is about 2k less than all the other brands. The advantage here is a compromise of compactness vs higher RPM's with less reciprocating weight.

If removing the cams was the only purpose of removing the tensioners, you were sweating for nothing. After removing the tensioner bolt, pull the chain up, insert a long thin screwdriver between the chain and tensioner, release the pawl, take the chain up. Remove the cam.
Search around, there were descriptions with pictures for mechanically challenged.
 

·
Registered
Joined
·
944 Posts
Discussion Starter #18
If removing the cams was the only purpose of removing the tensioners, you were sweating for nothing. After removing the tensioner bolt, pull the chain up, insert a long thin screwdriver between the chain and tensioner, release the pawl, take the chain up. Remove the cam.
Search around, there were descriptions with pictures for mechanically challenged.
The tensioners were coming out because I intended to install APE manual units.
 

·
Registered
Joined
·
944 Posts
Discussion Starter #19
When you get an idea of how much your fuel economy has been reduced, would you report back? That is, if you can stop twisting the throttle and giggling? I would expect a 5-8% drop based on looking at PC maps, and even more for you right now as you are probably getting on it harder than usual.


Sent from Motorcycle.com Free App
Your question came up in Blair's original thread. Blair's answer was fuel economy after this mod is more of a function of how hard one twists the throttle. I live in the country so I get my gas from an ethanol free dealer in 5 gallon cans so I wouldn't be able to accurately measure it without a lot of effort. The bike has always been good on gas so I don't think about it.
 

·
Registered
Joined
·
944 Posts
Discussion Starter #20
Spent Thursday evening taking the valve covers off, cleaned the surfaces thoroughly, and then applied the sealant like I should have in the first place. I waited until today at 5pm before taking an hour's ride. No oil seepage that I can see. I took the bike out to a rural road that is twisty with some steep hills to test the torque characteristics. I chose one hill that is quite steep and long for a test in 5th gear at 40 mph. I simply approached the hill at 40mph and held the throttle steady to see how much speed I lost and how the engine felt/sounded. Only lost 2mph with a steady throttle and the engine sounds incredibly tight and quiet. It felt as though the engine was yawning at this hill. I DID receive an IM stating that he did the swap about a year ago and is experiencing a bog when he raps the throttle open at low rpm's. I made a suggestion as to what it might be but this might possibly just be the nature of the beast. Personally, I wouldn't suddenly hit the throttle wide-open at low rpm's due to this would be lugging the engine. I'll try it once and see what happens for comparison.
 
1 - 20 of 26 Posts
Top