[southcaroilnawilliams]

Hey there, it's been interesting following your posts re the ds90 upgrade. I'm doing the same as you have although I have only just installed it and not started the tuning process . I'm based in New Zealand and Cam-am is a rare brand let alone getting up grade bits for one. I got the Hetrick power up kit for my boys bike. Apart from having to beat the **** out of the tank so the carb fits all the other stuff fits great. I found a way to use the RPM chain tensioner properly, I fabricated a small bracket out of steel, drilled hole in it and bolted it to the original tensioner mount, spot wielded each end to secure, then drilled another hole at only end of bracket for the RPM unit to fit straight onto, fits and works mint! I'll post a pic when I return hm in a few weeks time.
Is the bigger head a must?? It's the only thing I have not done yet.
Cheers
Greg

No it is not necessary. However I feel like there is some good power to be gained. The intake port is substantially bigger and if you are using the larger intake with the pe20 carb I think it will definitely benefit you. The port on that intake is so much larger than the stock head that it will cause turbulence as the air/fuel enters the cylinder head. No it is not necessary but I feel like it would definitely be a substantial improvement. It also has a bigger camshaft as well.

 

[southcaroilnawilliams]

Ok so after a day of tuning and disappointment I have learned a few things. If you have a pe20 carb and it constantly shows a rich condition no matter what you do as far as jetting you likely have a defective carb. I double triple checked timing, compression, spark, multiple heat range plugs, and jets. I tuned and tuned and tuned and finally called justin. Told him what was going on and that I was so frustrated that I ordered a stock head gasket and was ready to scrap the whole project all together and he stated that he had a customer with the same scenario and that it wound up being a defective carb. He said the guy sent his back and he tried it on a good running bike he had that ran the pe20 and he had the same issues with it. I could get mine to run ok on the top end but the idle circuit I could not get running right unless the air screw was almost ready to fall out and the idle was a good bit higher than it should. Even then it still wanted to hunt at idle. I am hopefull this is the issue as I am almost certain it is. The carbs are mass produced cast aluminum and I am sure the qc is not as stringent as the space program. My local shop said he had a bad fcr carb out of the box but had never seen a pe series bad out of the box. Keihin is still one of the best makers out there but once in a while I guess you get a lemon. I got one. Just my luck. The bike only has maybe 2 hrs on it thus far. The only reason I did the conversion so soon was because the float on the stock carb got hung up after the first 30 min of operation. Had to take the whole bike apart to get to it and decided to go ahead and do the conversion. So I guess I have a carburetor curse with this quad. Hopefully my luck changes!

Oh man that sucks ass!! I probably would have thrown the carb into the wall of my garage. I'm assuming Justin is sending you another carb, right? Hope the next carb is good to you!

I was very pissed. I have been working on thumpers and 2 stroke motors all of my life and have never encountered a scenario like that one. Never had a bad new carb. Have heard of it but guess I have a black cloud over me right now. Soon as I get it sorted out I am going to start looking at the suspension. I am going to get some measurements on the stockers and see what I can find in those lengths. I think I can find a cheaper solution than the elkas. Although they are some of the best out there I think I can find a cheaper solution. If I can find something that has adjustable compression and rebound I will be happy. The front suspension while better than most out of the box is nice I feel it is lacking in the rebound department. I think it is sprung well and the compression seems close the rebound sucks. The rear is better than the fronts but it still leaves a little to be desired. I think I can find something around the 400-500ish range for the front and rear. Maybe cheaper. I am going to see if I can find something used that I can rebuild on my own but don't know yet. Have not really dug into it that deep yet. What are you going to do? I think I will try and find some smaller rear tires as well. Not worried about ground clearance. It will definitely put more power to the ground with smaller lighter tires. Especially with the 33 tooth rear sprocket I am running.

 

[mcclelland32]

I was thinking smaller tires for the rear also but have not really looked into it. Just got the head today. probably won't install it until next week or so. thinking of porting the exhaust port a little. I really want to do a big bore. I need to break the motor down and take some measurements. center of wrist pin to the top edge of the piston so I know the wrist pin height we got so I can search for a piston. Called Hetricks and they can order a custom wiseco piston from one of their suppliers but that is about $225 for a 54mm. I saw a cylinder with a 54 bore for these and it is really thin on the sides. Not liking that, plus then I have to worry about too much compression for the starter. I would like to find a 52mm or 52.4mm piston. I got a shop (local) that will do a custom sleeve for around 3 bills. Just need to find a piston I want to use. A new cylinder for this thing is stupid expensive and from what I'm being told the outlaw 90 is the same sleeve just 2mm taller. The price is almost half of the DS90X cylinder. Neighbor has a 2013 outlaw 90 so I'm going to have to take some measurements from that too. I'm probably going to look on the scooter side for a piston, they have so many options it is crazy.

So the head looks just like the head from tbolt (trail bike race head). With valves 25/22mm vise 23/20mm.
Trail bike Race Head ONLYFits CRF50 - Pit Bike Engine Parts - Cylinder Heads & Parts - TBW0949 - TBolt USA, LLC

 

[mcclelland32]

I was thinking smaller tires for the rear also but have not really looked into it. Just got the head today. probably won't install it until next week or so. thinking of porting the exhaust port a little. I really want to do a big bore. I need to break the motor down and take some measurements. center of wrist pin to the top edge of the piston so I know the wrist pin height we got so I can search for a piston. Called Hetricks and they can order a custom wiseco piston from one of their suppliers but that is about $225 for a 54mm. I saw a cylinder with a 54 bore for these and it is really thin on the sides. Not liking that, plus then I have to worry about too much compression for the starter. I would like to find a 52mm or 52.4mm piston. I got a shop (local) that will do a custom sleeve for around 3 bills. Just need to find a piston I want to use. A new cylinder for this thing is stupid expensive and from what I'm being told the outlaw 90 is the same sleeve just 2mm taller. The price is almost half of the DS90X cylinder. Neighbor has a 2013 outlaw 90 so I'm going to have to take some measurements from that too. I'm probably going to look on the scooter side for a piston, they have so many options it is crazy.

So the head looks just like the head from tbolt (trail bike race head). Except now the tbolt has even larger valves 25/22mm vise 23/20mm.
Trail bike Race Head ONLYFits CRF50 - Pit Bike Engine Parts - Cylinder Heads & Parts - TBW0949 - TBolt USA, LLC

Need to correct my post above. The valves are the same size 25/22mm. Talking about the tbolt and Maximum RPM heads. stock size should be 23/20mm.

 

[southcaroilnawilliams]

So I got the new carb in yesterday and to my amazement it works like it is supposed to! It actually idles right and does not run rich. I will say this the jet settings that Justin told me was off. Way off. I currently have a 42 pilot and it is just about right. I think I need a 44 to 48 to make it perfect. He told me that I should start with a 62. Which I might work with the stock head I guess but my plugs told me that was way to rich. I had the 42 from one of my 450 r's so I put it in and bam! I am very close slightly lean. I have a cr6hsa plug in now with race gas seems about right . I am going to heat cycle the motor a few more times before my final verdict but I can see the light at the end of the tunnel. Installed the front variator as well and I have to say it is about the same as stock. I would not buy it if I had to do it over again. I weighed the rollers and they are 5 grams. The stock rollers I pulled out are 7 grams. The clutch engagement is probably 500 rpms higher than stock. The face angle is maybe 1 to 2 degrees different. I finally feel like I have a good baseline to start turning from. Going to do some real testing tomorrow with my boy. It has taken three weeks to get here and thank God I did it in the winter and it has rained every weekend because he would have been driving me crazy wanting to ride. I think by spring we should be dialed in for sure. I will let you know what my final jetting and needle position ends up being. Should be a good starting point for you. To be continued. .....

 

[mcclelland32]

So I got the new carb in yesterday and to my amazement it works like it is supposed to! It actually idles right and does not run rich. I will say this the jet settings that Justin told me was off. Way off. I currently have a 42 pilot and it is just about right. I think I need a 44 to 48 to make it perfect. He told me that I should start with a 62. Which I might work with the stock head I guess but my plugs told me that was way to rich. I had the 42 from one of my 450 r's so I put it in and bam! I am very close slightly lean. I have a cr6hsa plug in now with race gas seems about right . I am going to heat cycle the motor a few more times before my final verdict but I can see the light at the end of the tunnel. Installed the front variator as well and I have to say it is about the same as stock. I would not buy it if I had to do it over again. I weighed the rollers and they are 5 grams. The stock rollers I pulled out are 7 grams. The clutch engagement is probably 500 rpms higher than stock. The face angle is maybe 1 to 2 degrees different. I finally feel like I have a good baseline to start turning from. Going to do some real testing tomorrow with my boy. It has taken three weeks to get here and thank God I did it in the winter and it has rained every weekend because he would have been driving me crazy wanting to ride. I think by spring we should be dialed in for sure. I will let you know what my final jetting and needle position ends up being. Should be a good starting point for you. To be continued. .....

Yea, Justin told me the same jetting and it just sounded like it would be rich. How is that clutch working? If you hold the rear grab bar on your kids quad and have him go WOT can you hold the quad in one spot or will it drag you? Glad to hear your carb nightmare is over!

 

[mcclelland32]

Selling a koso variator and maximum rpm compression springs. Add is here: Message - Can-Am ATV Classifieds

Anyone interested

 

[southcaroilnawilliams]

You do something different with your clutch.? I think I am going to change the rollers in mine back to stock. It is good but the clutch comes in a little high. Would be good for racing but on the trails I like the lower engagement of the stock rollers. I would say at least 2000 to 2500 ish. I wound up with the 88 main needle in the second position and the 42 pilot. I think it is just about right. It has been tough getting rid of the bog from closed to wot. That has a lot to do with the fact there is no accelerator pump. It has been so damned cold the last couple of weeks we have not got a chance to run it much. I am guessing with the gearing on it we are running at least in the 40 mph range. I am going to GPS it soon as it warms up. I will also be ordering an oil cooler for it as well. The motor gets damn hot and I am sure it will help protect my bearings and surfaces much better. Will keep you guys posted with my findings.

 

[southcaroilnawilliams]

So I got the new carb in yesterday and to my amazement it works like it is supposed to! It actually idles right and does not run rich. I will say this the jet settings that Justin told me was off. Way off. I currently have a 42 pilot and it is just about right. I think I need a 44 to 48 to make it perfect. He told me that I should start with a 62. Which I might work with the stock head I guess but my plugs told me that was way to rich. I had the 42 from one of my 450 r's so I put it in and bam! I am very close slightly lean. I have a cr6hsa plug in now with race gas seems about right . I am going to heat cycle the motor a few more times before my final verdict but I can see the light at the end of the tunnel. Installed the front variator as well and I have to say it is about the same as stock. I would not buy it if I had to do it over again. I weighed the rollers and they are 5 grams. The stock rollers I pulled out are 7 grams. The clutch engagement is probably 500 rpms higher than stock. The face angle is maybe 1 to 2 degrees different. I finally feel like I have a good baseline to start turning from. Going to do some real testing tomorrow with my boy. It has taken three weeks to get here and thank God I did it in the winter and it has rained every weekend because he would have been driving me crazy wanting to ride. I think by spring we should be dialed in for sure. I will let you know what my final jetting and needle position ends up being. Should be a good starting point for you. To be continued. .....

Yea, Justin told me the same jetting and it just sounded like it would be rich. How is that clutch working? If you hold the rear grab bar on your kids quad and have him go WOT can you hold the quad in one spot or will it drag you? Glad to hear your carb nightmare is over!

It will go for sure. No problems with the engagement. I can power brake it with me on it sitting on the seat. Not too good for the belt I am sure. But I did test the power that way. I am going to see if they make a heavy duty belt for it as well.

 

[mcclelland32]

Oil cooler is going to be a must in the near future for me. Gets hot just like you said. Just pulled the motor out and took off the head to put in the big valve heas and crushed a damn 8x12 dowel so now I have to wait and hope one of my moto stores near by has one in stock. Fell off the bench and ended up underneath my foot and the floor so not in a usable condition anymore.

Still using the stock clutch with a koso bell. Grabs good now. was not grabbing that well until the shoes wore to the clutch bell. I'm using the stock variator and drive face so selling the koso. let me know if you find another belt. I ended up ordering a belt from Justin to have an extra in the parts box. It is a bando which is oem.
I'm waiting for some (15x12) 7,8,9 gram rollers to get here and I also ordered a NCY lightweight clutch with a NCY clutch bell. Will let you know how they work out.
Rear clutch bell is 16spline and from variator is 15 spline. I still want to do a 52.4mm big bore when the riding season is over. Have a little more research to do on a piston.

 

[southcaroilnawilliams]

I think I might go back to the stock rear sprocket gear size. I don't feel like I can use the entire rpm range with the 33 tooth rear sprocket. Plus I think it would be more useable for the trails. With me on it I can't get it to hit the rev limiter and his balls are not big enough to try it yet. He rode some more today as it was actually nice enough to ride. A balmy 51 degrees outside today. Let me know what you come up with on the clutch I am interested to see what the heavier rollers do to the engagement. I know they will make it come in sooner. It seems like I can smell the belt on mine after he has ridden it for 30 minutes or so. Doesn't seem to be slipping sooooo don't know. Although I am sure it is as it's the nature of the beast. Keep me posted. I also am going to get a 40 pilot as well and see how she does. I tried a 45 and it was not right. Always hunting for idle. I am going to order a few more main sizes in both directions. The 88 is pretty good but I think I can make it better. My plugs look pretty good but I am still stuck between richer and leaner. I only have the 90 and a 100 and nothing in between. It takes gas well but I think I need to play with it a little more. The exhaust is actually pretty damn loud. I didn't realize how loud it was until I went inside while he was riding to grab something and I can hear it clearly. No biggie but it is pretty damn loud. Keep me posted on what you come up with as I am interested in your findings.

 

[mcclelland32]

Yes the exhaust is crazy loud! I ended up taking the screen out and made a spark arrestor like the stock exhaust with a 3/4" tube and some 18 gauge sheet metal. better on the ears and not so annoying. I installed the big valve head and used the stock carb. ported out the intake to match the head. jetting is way off. so bad that it is crappy on take off. no balls! and acts like it hit the rev limiter at 3/4 throttle but i know that is saying she is really lean. I would like to keep the stock carb for now only because with the uni filter on the pe20 carb it gets loud when on the throttle and the stock carb has the air box to keep the noise down. Going to try and play with the jetting so we will see. I do know the dome is deeper by a little over 2mm on the big valve head so that means lower compression. I had this crazy spark on the back rear motor mount bolt. When I took off the stupid box around the carb I moved that ground wire to the frame. So today I noticed when I rev it high it would spark between the back bolt on the upper motor mount to the engine case. I was terrified with a WTF is going on and started trouble shooting. I no longer have that spark after moving the ground wire to the intake bolt. Will keep you informed on the rollers and clutch.

 

[mcclelland32]

I think I might go back to the stock rear sprocket gear size. I don't feel like I can use the entire rpm range with the 33 tooth rear sprocket. Plus I think it would be more useable for the trails. With me on it I can't get it to hit the rev limiter and his balls are not big enough to try it yet. He rode some more today as it was actually nice enough to ride. A balmy 51 degrees outside today. Let me know what you come up with on the clutch I am interested to see what the heavier rollers do to the engagement. I know they will make it come in sooner. It seems like I can smell the belt on mine after he has ridden it for 30 minutes or so. Doesn't seem to be slipping sooooo don't know. Although I am sure it is as it's the nature of the beast. Keep me posted. I also am going to get a 40 pilot as well and see how she does. I tried a 45 and it was not right. Always hunting for idle. I am going to order a few more main sizes in both directions. The 88 is pretty good but I think I can make it better. My plugs look pretty good but I am still stuck between richer and leaner. I only have the 90 and a 100 and nothing in between. It takes gas well but I think I need to play with it a little more. The exhaust is actually pretty damn loud. I didn't realize how loud it was until I went inside while he was riding to grab something and I can hear it clearly. No biggie but it is pretty damn loud. Keep me posted on what you come up with as I am interested in your findings.

Even with the stock rear sprocket. I could not hit the rev limiter on the maxRPM CDI. The only time I ever hit the rev limiter was with the stock CDI, koso variator with 4.75gram rollers. changed out the rollers to the stock (7gram) rollers and still did not hit the rev limiter in the same distance but the top speed was about 1mph more with the stock rollers and it felt stronger all through the rpm range. All testing was done with the maxRPM exhaust.
I think I got spoiled on the KFX50 GY6 motor. So easy and cheap to make crazy power for a little quad. For a NCY transmission kit and Naraku BBK was about $500. That thing would hook up! I could spin the tires on the street. It would wheelie from a dead stop. Only sold it because the suspension sucks on single A-arm quads.
Now the Can-am different story. Parts are expensive and nobody makes bigger cylinders. Heads are compatible with CRF50 heads with just a little modding. The CVT part if from a JOG 90, just a different belt length. Just remember the variator is 15 spline and the clutch is 16 spline. Spoke to the guy from T-bolt (forgot his name). He was telling me, in a month or so they will have back in stock a roller rocker head for the CRF50 and it will fit on the DS90. I'm interested to see that! He also told me the DS90 piston should be the same deck height as the 52.4mm pistons used in any of the 107cc or 124cc pit bikes like the SSR, Thumpstar, Pitster Pro, etc.. Will get back to you on my findings. Not going to get into that until riding season is over. Also I have heard the DS90 and the Polaris outlaw heads are almost identical. Outlaw head is supposedly 2mm longer but if you look it is alot cheaper to buy a new one than the DS head. So I'm thinking of getting the Outlaw head mil it down 2mm and use that as my 52.4mm bored head. Summer projects!!! Neightbor has a 2013 outlaw 90 so I will mic it and let you know.

 

[mcclelland32]

Can you do a compression test and tell me what you get? I know something is not right. I'm getting 100psi. I did notice when installing the head and cycling the engine looking in the intake port, I could see bubbles around the intake valve seat when cycling to top dead center. I sprayed the head with oil prior to installing. So I'm assuming the valves were not seated properly to the the head. Kinda pissed off at the moment...

 

[mcclelland32]

Took the head off again and going to lap the valves. Justin wanted to send me a new head but I told him to send me a gasket kit and I will lap the valves. Told Justin about the compression and I mentioned the dome was deeper and he did not remember exactly what the compression went down to but thinks it was around 140-150. I prefer more compression than that, so I started looking for a domed piston with the same deck height or something close that I could modify. Here is a Wiseco CRF70 10.5:1 compression piston next to the stocker. Wiseco # 4880M04800 is the correct diameter piston. The piston in the picture is a 47.50mm. The 48mm will be here monday. Just passing on the info...

 

[mcclelland32]

Piston is a go! No clearance issues with the piston and the big valve head. I got the piston today. I still have not received my gaskets but I wanted to install without gaskets to give me the minimum piston to valve clearance. No issues without a gasket so with a gasket it will give me more clearance. The head gaskets from maximum rpm are thicker than the oem one so I think I'm going to go with a oem head gasket.

 

[mcclelland32]

Lapped the valves and even used a .50mm head gasket from a polaris outlaw 90 with the crf70 domed wiseco piston and the most I could get the compression was 130psi. Had to use the polaris head gasket because can am said the oem one will ship in april... I was not happy with the low compression. yes it ran fine but it was not snappy as if the compression was higher. So I put the stock head back on with the crf70 domed piston and much better compression is around 175psi. I'm using the stock exhaust that has been modified.
I have the NCY lightweight clutch and the NCY clutch bell and plan on installing it this weekend. The clutch and bell were less than $100 together. Will post my findings when I'm done.

Any one interested in buying my maximum rpm exhaust for a DS90X?

 

[mcclelland32]

Well I could not wait until the weekend..so I installed the NCY clutch and the NCY clutch bell with some 9gram rollers. By far the best set-up for us. I have used the oem clutch bell, the koso clutch bell and the ncy clutch bell. I choose the ncy clutch bell. It has a sandpaper type texture on the inside. I guess koso use to have it also but for some reason they stopped putting the texture on it. I expect the texture to finally go away with wear but in the process it will also make the shoes on the clutch have more contact than without it. I have seen several clutches and the wear is never on the whole shoe but only a portion of the shoe. The NCY clutch is nice and not pricey.Gets my vote! Definitely like the 9gram rollers (15x12) better than stock. Chris said he weighed the stock ones and they were 7grams. With the 9gram rollers, NCY clutch, and NCY bell it engages sooner which is a nice smooth grab and I get no bog from a dead stop to WOT. Even going up hill. All testing done on the asphalt to give me the most traction. Top speed is higher. Ran down 3/4 of the block in the dark with the gps and was 33.5mph. Going to try 10 and 11 gram rollers just to see where the sweet spot is but for now 9grams is good for us and the trail riding we do. Here are the part numbers.. The NCY parts were ordered from scooterdomain.com out of FL.
NCY clutch bell part#1200-1019, NCY lightweight clutch part#1200-1018, NCY 9gram rollers part#1200-1043-9G

**Looking to sell a maximum RPM exhaust, koso variator, koso clutch bell, 1500rpm and 1250rpm torque springs, 4.75gram and 5.5gram rollers. Willing to let everything go for cheap. PM me if interested. All parts were ordered from maximum rpm.**

 

[mcclelland32]

koso clutch bell and oem clutch

 

[mcclelland32]

Here is a picture of a 54mm sleeve installed in a cylinder. paper thin and no way in I would think this is going to be reliable. Probably going to run hot.