ktm/husky 300. whos spent time making more power?

[eric82930]

https://www.ebay.com/itm/Digital-Mo...849003?hash=item1eeb5e5dab:g:l9cAAOSw-RRXCJb5

i tried to put this cdi on my 2 stroke today and decided against it because i don't have the setup to run dc electrics. my 450 had a much bigger 3phase stator and would kick start a clean recified dc to feed the cdi. this would be fine on an estart 2stroke though as long as the battery has 5v left in it, it would still kick.

the stock ktm 2k stator cdi charge coil only has a low voltage ac output to the stock cdi box so it must get multiplied inside the box to charge the hv capacitor...
i guess i could try to do a full wave recifier on it as a dedicated cdi feed but that would totally screw up the wonderful simplicity of my 2stroke....

 

[portgrinder]

Haven’t tried much more, other than a 15.5/1 head. Squish at .049 and about 190psi.
It bumps the entire curve up another 2-3pounds, so it’s near 37-40 tq for a pretty wide rpm band. That gets us up to ~8tq and 10hp in spots over stock

 

[2smokin]

Portgrinder, It sounds like you may have had a 500? Just curious, If so what is the reason you are thinking of trying to get more power from a smaller bike?

Vibration, hard starting and narrow power are the reason I couldn't justify keeping my 500 I was really glad to see it go. Hopefully the brc might fix the first two issues. Iv'e been dabbling in ktm 360's and 380's lately and raising the exhaust port about an inch seems to be what they like to be a good snowbike.

And I don't agree with the "no replacement for displacement" in the field of snowbikes. If it was true why isn't the panthera in every snowbike out there by now....??? Every 450 made in the last 5 years makes more power than the 500's and they have half the power strokes. Its about airflow in this case which probably needs to be the main topic of this discussion on the 300's.

I'm not an engineer by any means and kinda sloppy in my approach to tuning but I ride snow 2-3 days a week oct - july and have tons field trial and error experience to see what works on the snow. My conclusion is stock mx bikes always do best because the factories tune them for peak hp. The big bores never seem worth it because they trade hp for torque because the peak airflow is choked off somewhere in the system. Big bores also vibrate more, start harder and are less reliable. High comp is almost always better for high altitude as long as it will still start.....

I'm super biased to 2 strokes and 1st choice would probably be a 60hp GP tuned counterbalanced 300. If the brc can make reliable 70hp it will probably be my 2nd choice until ktm starts building the 2 stroke 500SBS "snow bike special". It will come with the tires in a separate box with a warning label that says "INSTALATION MAY RESULT IN BODILY HARM OR DEATH"

I'm biased as well! haha, by GP standards https://www.vitalmx.com/forums/Non-Moto,21/2-stroke-250-Yamaha-made-97-hp-300-rpm-power band,1230012
of course its a twin and a 300rpm power band would be rough even with a cvt, But im certainly interested to see how reliable a 300 single would be in the 60-70hp range. Im thinking about getting a pipe from NPP like portgrinder has suggested in the past and throwing some compression and port work at my 18 300xc. I personally hate to slip the clutch so I would sacrifice a few hp to have a functional power band that i could roll in to. As far as the Brc reliably making 70hp that will be interesting.

 

[2smokin]

Ya that would be a nice setup.

I think it needs more timing. Anyone played around with boxes (are their any?) or an old school offset key?

http://www.powercdi.com/en.html

I wonder if this has any merit, would be nice if it wasn't so expensive

 

[portgrinder]

egt's were high relative to other factors that said it was tuned right. that usually means it needs more timing.The head smartened it up a lot. kinda does the same thing.

I might oblong the holes on the ignition pickup. get a degree or two to test anyhow.

if anyone wants the 13.3/1 head, let me know. I would sell it.

you need a wide powerband. and this 300 is real wide. its not gonna touch a proper running 500 but I bet it will be every bit as good as a strong 450

The BRC is a whole whack of cash. and its not in the new frame. and it doesn't seem to make much power

 

[portgrinder]

Anyone know how many watts the elect system on these bikes can handle without draining the battery?

 

[eric82930]

The rotating mass definately matters big time for fun factor even more so in the spring snow. It's exactly like on dirt. The 450s get the whole shot every time but the 2 strokes are still more zippy and fun. It's exactly the same difference between artic cat 800 and 1100t. It matters! I was even shocked when i switched from my 2k3 to the lighter 2k1 flywheel on my 380 long track. It felt like it gained 5hp (it didn't) but it's just the half second quicker spool up makes for bigger grins. It's so much more fun I'm willing to run the 2k1 without the extra watts for my grip heaters. But I'm the guy who REMOVED the e-start from my 150xcw so I could install the lighter sx flywheel. Take it for what it's worth. If your high marking ride a 4 stroke. If you just want to have fun get a smoker and do whatever is necessary to keep it from freezing up on deep days.

 

[portgrinder]

Did some more runs.

- v force reeds are even steven. No gains
- Lectron gains 2-3 all the way thru. That was a 40. 38hv is almost the same. Gives up maybe one on top.
- sx box gained a couple in the mid and lost up top
-ktm fmf powerparts pipe lost a few in the mid and gained a couple up top.
-I moved the ign pickup to add timing. No real change.

So we ended up with a 40 Lectron, custom pipe and 15/1 head. Stock jug. C111 @ 30:1. Pretty good gains.

 

[wwillf01]

Did some more runs.

- v force reeds are even steven. No gains
- Lectron gains 2-3 all the way thru. That was a 40. 38hv is almost the same. Gives up maybe one on top.
- sx box gained a couple in the mid and lost up top
-ktm fmf powerparts pipe lost a few in the mid and gained a couple up top.
-I moved the ign pickup to add timing. No real change.

So we ended up with a 40 Lectron, custom pipe and 15/1 head. Stock jug. C111 @ 30:1. Pretty good gains.

Nice.... great torque numbers... who's pipe?

Sent from my SM-G975U using Tapatalk

 

[portgrinder]

NPP

we tried some that made the same peak but none have the big torque gains thru the mid. quick little vid.

 

[2smokin]

Finally got around to ordering an NPP pipe, Neil said he is making some next week if anyone else wanted to try to get one soon. He also mentioned that you hated the peaky max hp prototypes on the snow, was it hard to stay in the powerband? I hate clutching into the power so i'm excited for the broad power. Did a little less compression on pump gas make a large power difference?

 

[portgrinder]

I found the power was just too far away and it didn't hang in there when you loaded it up.

this setup will be the exact opposite. if you rev it 7-8 and it starts to work hard, the motor will make more torque as it pulls down. it will hang in there way better instead of having to shift.

never been a fan of increasing compression on pump gas. i'm sure it could be done. just not something I want any part of.

 

[2smokin]

I'm excited for the torque, not being able to hold a gear when hitting a hill has always been my 300's downfall.

 

[portgrinder]

I made a few good 300's though. Best bang for the buck - raise cylinder with thickest base gasket or two. shoot for .075" to .080" then shave the head to get the squish back to 050-060 (for high altitude).
Then if budget allows use a pc2 or fatty pipe, vforce and a bigger carb. A

So I was doing some math. funny enough, I came up with almost that exact same number that the jug should go up. i'm gonna do that and machine another head to sink down into the bore and get 15/1. we'll give that a whirl and see how it shakes out. pretty cheap playing around anyhow.

 

[HalfBrit]

You guys are making this a fun read. I'm new to 2 strokes( about two years now). I have 4 ktms now. 3x 300s and 250sx. Are you raising the cylinder to get the exhaust or intake ports higher? It changes the power valve opening too?
Could you show a pic of how you are you are chucking the head for machining? I'm a novice machinist. but I do have a bridgeport style knee mill and 10x24 lathe.

 

[NEWDUCK]

You guys are making this a fun read. I'm new to 2 strokes( about two years now). I have 4 ktms now. 3x 300s and 250sx. Are you raising the cylinder to get the exhaust or intake ports higher? It changes the power valve opening too?
Could you show a pic of how you are you are chucking the head for machining? I'm a novice machinist. but I do have a bridgeport style knee mill and 10x24 lathe.

Ive always just used a spark plug that Ive turned down and hang onto that for single cylinder heads in the lathe. If you try more compression on the 250sx id be interested in the results. I tried it for a bit and lost bike lengths in the top end pull.

 

[HalfBrit]

Ive always just used a spark plug that Ive turned down and hang onto that for single cylinder heads in the lathe. If you try more compression on the 250sx id be interested in the results. I tried it for a bit and lost bike lengths in the top end pull.

The one I'm going to run is a 300sx powerparts kit. Maybe I shouldn't mess with the head? I have an extra exc head I can test with higher compression.

 

[eric82930]

Assuming we all ride at high altitude then yes, If you have a spare head definately cut it to higher comp and try it. If you go too high you might loose top end but then you could always add a thicker base gasket to get it back and possible gain everywhere. Gotta pay cloase attention if you don't have a dyno compare back to back against a know riding partner or hill climb test in similar conditions. I've swapped heads and base gaskets up on the mountain many times. Just make sure its a nice sunny day and your buddies aren't waiting for you...

 

[portgrinder]

it seemed at 15/1 it started to start tapering off on the top end, but it was still way better than stock.

top of my head from what I remamber...if you take a straight slice off the head and end up at .050 squish you will be up 2-3 ft/lb thru the whole power curve. 15/1 gets you about that much again, say up to 7500 and then maybe only 1 more past there.

ya raising the cylinder lifts everything at once. exhaust and transfers

 

[portgrinder]

Pic of the pipe. It’s tucked in a lot nicer than most.