Xr/klx mutant motor

[cozza123]

Amazing dude A++++

 

[storminnorman07]

so got the springs in did some testing they are only about 8% stiffer than takie springs. i did some playing and cutting and managed to up spring pressure by 40% over the takie spring setup. so if these clutches slip this time i'm going to be focked, but i think they should hold. got everything buttoned back up and ready for another crack at it tomorrow. hopefully the clutch and tin plate was my last hang up and all goes well tomorrow. If all goes well tomorrow already got a slot penciled in for a couple pulls on the dyno sunday. if nothing comes unglued i'll try to get a lil clip of mutant in action. however it wont be very impressive with me piloting it nor will video quality be good. so i guess til then stay tuned ;-)

 

[storminnorman07]

how about that she stayed together this time. runs faster than tiger piss and nothing with 2 wings can catch her....lol well she runs pretty strong any how. i got off work buddies were crying like a couple school girls that just pissed their pants on the playground cause its cold it was raining and it was damn near dark but i forced them to come out and get all 3 conversions tuned a lil better for some dyno pulls. by the time i did some break in and got it tuned a little better (jetting is still a lil off) as you can see it was virtually dark so it made for one hell of a ride on that strip mine soil. i couldnt see chit i ended up popping a tube but least i got a lil video clip to show it in action. not a very good clip mind you but least its something. after getting to put some actual time on it i'm thinking i won't see the 22hp like i had hope. she def wants more carb and cam duration. which unfortunatly it will see neither due the piston valve clearance wont allow me to changed cam and frame restrictions won't allow a bigger carb. torque numbers should be pretty though. all and all i'm happy with how it runs. it stomps a mud hole in the takie kitted xr engines my buddies have and that was my biggest goal was to have a stronger running motor than a kitted xr 80/100. could she run stronger certainly cam and carb would give a nice boost in hp. there is other things i could have done to achieve higher numbers. but when building i wanted to maintain some longivity with it and not build a 3-5hour race motor.


http://www.youtube.com/watch?v=DdWuEjyRSBs

 

[bulldog93]

Sounds good.. Def need to ride in the day though.

 

[The_GDFP]

Nice! Man, that 80 trans is tight, with that much motor. I love the slick shifting upright, compared to the horizontals. "Area under the curve" should be WAY ahead of the revvier Tak-headed jobs, even if peak isn't much higher.

 

[doopsx3]

Man....that thing sounds SWEET!!!!!!! that bike will for sure live up to your fender graphic.......you Sir are are a mechanical master.....I would like to see that go up against the best that the peeesta boys have to offer....I am sure it would be no contest...... even if your jetting is not just right......keep the inventive thoughts churning in your head....you come up with the most outstanding out of the box cool stuff each time.....just friggin love it....I need one of these stuck in a XR75 frame ...lol

 

[storminnorman07]

Nice! Man, that 80 trans is tight, with that much motor. I love the slick shifting upright, compared to the horizontals. "Area under the curve" should be WAY ahead of the revvier Tak-headed jobs, even if peak isn't much higher.

Lol yea it is I like it alot more than the takie CR trans I had in my 50. No comparison between the 2 under the curve the mutant kills the tak-headed xrs. The +R does hold rpms longer than the mutant and will free rev faster. Yea i don't think mutant will show much more peak hp over the R head but under the curve its going to kill it

 

[storminnorman07]

well finally got to dyno all 3 bikes and to say the least i'm not impressed with the results. the takie kitted xrs pulled as i expected them to pull. my mutant on the other hand was a epic fail. havent had time to do some seriously looking and figuring but my thoughts are to much exhaust not enough intake runner and i never factored i'm running a longer rod than the bottom end i first dynoed this 4 valve head with. after about 4 hours of ignition timing and trying different jets to make sure they are tuned the best they can be this is the results....

mutant xr/klx dyno pull

takegawa + R kitted xr 100 FAR cry from the 18-20 i have been seeing guys claim out of this kit

takegawa stage 3 kitted xr 100

all 3 runs on one graph

 

[C70-TURBO]

No A/F readout on that dyno?..would def. help

 

[storminnorman07]

No A/F readout on that dyno?..would def. help

unfortunatly no sniffer on this dyno. dont think it would of changed the results though. i got a base line went richer and leaner on jets til it pulled their best. if jetting was slighly off on their best i wouldnt be able to do nothing about it cause it would of needed some odd ball jet size thats not readily available for purchasing. example the stage 3 for some ungodly reason i trusted my buddy was going to tune it so i had to do alot of playing with jets. i tried 4 different needles and bounced around on main jets til i found a needle that pulled cleanly 115main showed a decrease in hp and so did a 110 went 112 or 112.5 pulled best. didnt have anything inbetween the 2 and even if i did maybe a couple tenths of a hp difference. sniffer def would of cut alot of jet changing time down on it thats for sure.

 

[The_GDFP]

Between a stingy dyno, driveline losses and those little Japanese horses Tak measures by, I can see the low peak numbers. I'm baffled at the revs though. Clay's 125+R is still pulling, on the track, at 13. Ignition or pipe, maybe?

I don't remember if Mats graphed the 4V cam, but your Mutant numbers and overrev are decent considering.

 

[storminnorman07]

Between a stingy dyno, driveline losses and those little Japanese horses Tak measures by, I can see the low peak numbers. I'm baffled at the revs though. Clay's 125+R is still pulling, on the track, at 13. Ignition or pipe, maybe?

I don't remember if Mats graphed the 4V cam, but your Mutant numbers and overrev are decent considering.

i honestly feel takie is doing their dyno work off crank or off sprocket. what ignition is clay running? the stage 3 was running a bone stock honda ignition the R was running a lifan. i tried everything from fully advanced to fully retarded on ignition timing with the lifan. it made its best more so on the retarded side didnt have a timing light with me so i don't know what it was actually at. exhaust may be why. the stage 3 was running chp 70 pipe modded for conversion frame. the R was running a xr 100 yosi modded to fit the conversion frame. i think when i go back i'm going to try and see if the guy will let me throw his bone stock xr 100 on the dyno also so i can get a feel what kinda hp loss vs other dynos i have seen of stock 100 engines.

i had the yx cam cam doctored. i would have to go dig it up to give all specs. but i'm pretty sure intake lift was about .190 ex .183 and duration was in the ball park of 240 degrees. i know with my dohc 50 i was dynoing it hated big duration! with factory 124 cams it was like mid to high 19's, with big duration cams like 17-18 and with the smaller duration 95/105 cams it pulled 21.6. after seeing that and talking with some guys about cams i felt pretty confident the stock yx cam should pull pretty good.