|
Author |
Message |
binge |
This post is not being displayed .
|
binge Emo Kiddy
Joined: 03 Jul 2004 Karma :
|
|
Back to top |
|
You must be logged in to rate posts |
|
|
Kickstart |
This post is not being displayed .
|
Kickstart The Oracle
Joined: 04 Feb 2002 Karma :
|
|
Back to top |
|
You must be logged in to rate posts |
|
|
binge |
This post is not being displayed .
|
binge Emo Kiddy
Joined: 03 Jul 2004 Karma :
|
Posted: 21:08 - 13 Oct 2016 Post subject: |
|
|
Checking how the ignition was running tonight.
I've not marked it at TDC. I've just marked it at idle, and then revved it to see what the curve is like.
It seems to be retarding by about 10 degrees when under load.
Speaking to a chap with a Rotax 257 (SEM) he says his idles at 25deg advance, and backs off to 15deg when under load.
If this is anything to go by, then I guess mine is behaving correctly.
Now I just need to double check my timing is set correctly.
I thought I had already done this, but I guess I could have got it wrong.
If I can get some solid evidence that the ignition is okay, then I will go ahead and buy a pipe for it, then proceed with a rolling road and proper set up.
Video here:
https://youtu.be/1N5RaKTBmjE
The last thing that has got me thinking, is I keep reading about 'squish'.
I dont really understand the build process of these engines, and I just bought all standard gear when i rebuilt it.
Could I have got the compression/squish all wrong? ____________________ - Honda XL125S - CBR400 NC29 - VFR400 NC30 - CBR400 NC29 - TL1000R - TeeZeR Pit! - Bandit 12 - YZF450 - LuckyMX125 Pit! - Demon X XLR 140 Pit!
- Stomp KZ 160 Pit! - Demon X D-link 140 Pit! - CRF50F Mini-Pit - MonsterMoto 155cc MiniSM - Honda Chaly 150cc - Yamaha 98' R1
- Honda Chaly 140cc - Thumpstar 190cc 4v MiniSM - Aprilia RS125 Pit-Bike - |
|
Back to top |
|
You must be logged in to rate posts |
|
|
331X2 |
This post is not being displayed .
|
331X2 Crazy Courier
Joined: 10 Jul 2013 Karma :
|
|
Back to top |
|
You must be logged in to rate posts |
|
|
binge |
This post is not being displayed .
|
binge Emo Kiddy
Joined: 03 Jul 2004 Karma :
|
|
Back to top |
|
You must be logged in to rate posts |
|
|
331X2 |
This post is not being displayed .
|
331X2 Crazy Courier
Joined: 10 Jul 2013 Karma :
|
Posted: 21:54 - 13 Oct 2016 Post subject: |
|
|
OK, I was just thinking along the lines that if you'd been given Base/head gaskets that were too thick then you'd have low compression/wide squish that would make it run like a dog.
I would measure and compare everything to standard specs so you have a baseline to work to. If compression/ignition/fueling are in the right ballpark then you've got to be looking at the exhaust, maybe even bodge a standard exhaust on to see if it gets you up into the power. I'll try and dig out a good two stroke tuning book for you |
|
Back to top |
|
You must be logged in to rate posts |
|
|
stevo as b4 |
This post is not being displayed .
|
stevo as b4 World Chat Champion
Joined: 17 Jul 2003 Karma :
|
|
Back to top |
|
You must be logged in to rate posts |
|
|
331X2 |
This post is not being displayed .
|
331X2 Crazy Courier
Joined: 10 Jul 2013 Karma :
|
Posted: 22:21 - 13 Oct 2016 Post subject: |
|
|
I was thinking more along the lines of a wide squish indicating the barrel or head being jacked up above standard specs and leading to low compression. I may be off down the wrong path entirely but it's easy stuff to check and cross off the list of "things that will wreck your head" |
|
Back to top |
|
You must be logged in to rate posts |
|
|
Kickstart |
This post is not being displayed .
|
Kickstart The Oracle
Joined: 04 Feb 2002 Karma :
|
Posted: 00:17 - 15 Oct 2016 Post subject: |
|
|
binge wrote: | Checking how the ignition was running tonight.
I've not marked it at TDC. I've just marked it at idle, and then revved it to see what the curve is like.
It seems to be retarding by about 10 degrees when under load. |
The only figures I have are for 6k and 10k, with ignition retarding 7 degrees between those rpm. However not sure how much it retards before then.
binge wrote: | If this is anything to go by, then I guess mine is behaving correctly.
Now I just need to double check my timing is set correctly.
I thought I had already done this, but I guess I could have got it wrong. |
It is a pain to do with a dial gauge and lots of quick changes. Note that they were originally built to run on higher octane fuel (98 octane).
Do you have the instructions for setting the timing?
binge wrote: | The last thing that has got me thinking, is I keep reading about 'squish'.
I dont really understand the build process of these engines, and I just bought all standard gear when i rebuilt it.
Could I have got the compression/squish all wrong? |
You could, but people obsess over squish when it is just one factor. Probably more important is the compression ratio and if you reduce the squish without changing the combustion chamber shape then the compression ratio will increase (and as standard the uncorrect compression on a 123 engine can be 15.3:1 ). Too high compression will cause major engine damage, although a very narrow squish band can counteract that to an extent.
While running the compression lower than it should be will lose you a bit of power I would expect that to be in the region of 1~2hp, rather than the ~15hp I guess yours is down by.
All the best
Katy ____________________ Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing |
|
Back to top |
|
You must be logged in to rate posts |
|
|
binge |
This post is not being displayed .
|
binge Emo Kiddy
Joined: 03 Jul 2004 Karma :
|
|
Back to top |
|
You must be logged in to rate posts |
|
|
c_dug |
This post is not being displayed .
|
c_dug Super Spammer
Joined: 04 Sep 2007 Karma :
|
Posted: 14:24 - 15 Oct 2016 Post subject: |
|
|
Hi Binge,
Hadn't been following this thread much, which is a shame as I can probably be of some small amount of help.
I'm not miles away from Maidstone and I'm happy to swap a few bits over from my Tuono 125 if it'll help diagnose anything. Could also run side by side to see how they compare performance wise. My tuono hits redline in top at 80mph so they're probably geared reasonably similarly.
Drop me a PM if I can help in any way
Edit: just to clarify its a full power Rotax 122 with I believe a standard pre-restriction Aprilia exhaust and 28mm carb. All of the running gear and engine is identical to an RS125. ____________________ I am a bellend, I am a man of constant sorrow, I am a gummy bear, I am a rock. |
|
Back to top |
|
You must be logged in to rate posts |
|
|
Kickstart |
This post is not being displayed .
|
Kickstart The Oracle
Joined: 04 Feb 2002 Karma :
|
|
Back to top |
|
You must be logged in to rate posts |
|
|
binge |
This post is not being displayed .
|
binge Emo Kiddy
Joined: 03 Jul 2004 Karma :
|
Posted: 15:30 - 17 Oct 2016 Post subject: |
|
|
Awesome offer C-Dug.
Would be interesting to know what carb and setting you are running.
I'm hoping once I fit this exhaust (When it arrives) it'll be noticeably different, even if it's not set up correctly.
At least to a point where I can go 'yeah, that old pipe was dog-shit'.
Going to fit the pipe up, double check the ignition timing (yes it's a ball ache), warm it up, and double check the compression when hot too, as I've got a feeling it could be a little low on compression.
From cold, I can turn it over by hand, with the flywheel. Easily.
Can clearly tell when it rocks over TDC, but it's easy peasy to turn over.
If that's the case, it'll be wanting a barrel re-plate because it's a brand new piston and rings, cant be anything else. ____________________ - Honda XL125S - CBR400 NC29 - VFR400 NC30 - CBR400 NC29 - TL1000R - TeeZeR Pit! - Bandit 12 - YZF450 - LuckyMX125 Pit! - Demon X XLR 140 Pit!
- Stomp KZ 160 Pit! - Demon X D-link 140 Pit! - CRF50F Mini-Pit - MonsterMoto 155cc MiniSM - Honda Chaly 150cc - Yamaha 98' R1
- Honda Chaly 140cc - Thumpstar 190cc 4v MiniSM - Aprilia RS125 Pit-Bike - |
|
Back to top |
|
You must be logged in to rate posts |
|
|
chris-red |
This post is not being displayed .
|
chris-red Have you considered a TDM?
Joined: 21 Sep 2005 Karma :
|
|
Back to top |
|
You must be logged in to rate posts |
|
|
binge |
This post is not being displayed .
|
binge Emo Kiddy
Joined: 03 Jul 2004 Karma :
|
|
Back to top |
|
You must be logged in to rate posts |
|
|
stevo as b4 |
This post is not being displayed .
|
stevo as b4 World Chat Champion
Joined: 17 Jul 2003 Karma :
|
Posted: 21:01 - 19 Oct 2016 Post subject: |
|
|
The new trick Arrow pipe sounds cool, and will require many pics too! It will also suit your custom monster too, as it's another bit of essential bling, but should hopefully have some noticeable performance and weight advantages, and release a bit more of the MX'er sound too!
If it performs better from the get go even before setting up properly, then it'd make me want to cut the std MX125 pipe open to see if there was a nasty restrictor hidden inside just to satisfy your curiosity.
I reckon if you can get the timing set as per the std factory specs, and when you re-test the compression with a known decent tester and at WOT, hopefully you'll see at least 120psi.
If all that checks out, a couple of hours setting up the jetting on a dyno for the pipe and filter should have the beast feeling pretty mental and much quicker too! |
|
Back to top |
|
You must be logged in to rate posts |
|
|
binge |
This post is not being displayed .
|
binge Emo Kiddy
Joined: 03 Jul 2004 Karma :
|
|
Back to top |
|
You must be logged in to rate posts |
|
|
binge |
This post is not being displayed .
|
binge Emo Kiddy
Joined: 03 Jul 2004 Karma :
|
Posted: 22:39 - 09 Nov 2016 Post subject: |
|
|
Pipe finally arrived.
Incomplete, but hey ho, Luckily my original manifold and springs fit.
Messaged the seller, explained that I only received the expansion chamber despite the listing stating it comes with all fittings.
Seller has asked me to send a photo of exactly what I've received.
So I've gathered the seller is a fucking idiot, if they dont know what 'expansion chamber only' means.
Negative feedback I guess.
Pipe is on, and fits. Not quite as nicely as the original, needed a few swift smacks with a hammer on the mountings.
It starts. And it's fucking noisy as fuck. Sounds like a proper MX bike now.
Not gonna get chance to ride it until after the weekend as I need to put the car trailer, and the caravan off the drive to get the bikes down the side of the house.
So for now, it will remain in the garage.
Will report back when it's out on road test.
https://scontent-lhr3-1.xx.fbcdn.net/t31.0-8/15042190_375922606092104_8174967934658460384_o.jpg ____________________ - Honda XL125S - CBR400 NC29 - VFR400 NC30 - CBR400 NC29 - TL1000R - TeeZeR Pit! - Bandit 12 - YZF450 - LuckyMX125 Pit! - Demon X XLR 140 Pit!
- Stomp KZ 160 Pit! - Demon X D-link 140 Pit! - CRF50F Mini-Pit - MonsterMoto 155cc MiniSM - Honda Chaly 150cc - Yamaha 98' R1
- Honda Chaly 140cc - Thumpstar 190cc 4v MiniSM - Aprilia RS125 Pit-Bike - |
|
Back to top |
|
You must be logged in to rate posts |
|
|
stevo as b4 |
This post is not being displayed .
|
stevo as b4 World Chat Champion
Joined: 17 Jul 2003 Karma :
|
Posted: 00:49 - 10 Nov 2016 Post subject: |
|
|
Well it certainly fits in with the general theme of trickness and cool bling factor too!
I'm glad it's properly noisy and serious in a ringy tingy MX way too!
Let's hope the serious sound translates into some serious performance increase too! At least you know the engine itself is sound with a nice strong compression pressure reading too!
Oh and I had a thought about the very black rich looking plug too. If the OEM exhaust was very heavily restricted then it could make it run rich on std jetting, as don't the restricted RS125's run smaller jets and hotter plugs than the full power bikes? |
|
Back to top |
|
You must be logged in to rate posts |
|
|
binge |
This post is not being displayed .
|
binge Emo Kiddy
Joined: 03 Jul 2004 Karma :
|
Posted: 23:00 - 10 Nov 2016 Post subject: |
|
|
Well this evening I needed to check the electrics on the caravan as we're taking it away at the weekend.
So while it was hitched onto the van, it would have been rude not to pull it forward off the drive way, so I could squeeze the bike past the trailer and take it for a test drive.
Only a little ride up my road and back, some 100 meters.
Admittedly didn't get the bike properly warm, and there is also a minor blow on the manifold where it's not lined up quite right yet.
As I opened it up in first gear, it seemed a bit more boggy than before.
Obviously more air-flow in the new pipe, seeing as it's about 1/3 the weight of the original one.
As it burbled through a very short boggy spot, it came on the pipe.
And boy did it come on pipe!
Front wheel came straight up, a short shift in to second, straight back on the power, and front wheel didnt even get a chance to hit the floor.
Straight back up again, all the way through 2nd, and into 3rd gear.
Fucking mental.
I turned it around, and gave it a blast back to the house, and put it away with a huge grin on my face.
Next week, I'm taking it for a proper ride, in the day time, with my go-pro on.
Fucking awesome!
https://scontent-lhr3-1.xx.fbcdn.net/v/t1.0-0/p480x480/15037170_376542646030100_1440289817426448741_n.jpg?oh=d908812a676a62d807a6c99e8af047ec&oe=58C39976 ____________________ - Honda XL125S - CBR400 NC29 - VFR400 NC30 - CBR400 NC29 - TL1000R - TeeZeR Pit! - Bandit 12 - YZF450 - LuckyMX125 Pit! - Demon X XLR 140 Pit!
- Stomp KZ 160 Pit! - Demon X D-link 140 Pit! - CRF50F Mini-Pit - MonsterMoto 155cc MiniSM - Honda Chaly 150cc - Yamaha 98' R1
- Honda Chaly 140cc - Thumpstar 190cc 4v MiniSM - Aprilia RS125 Pit-Bike - |
|
Back to top |
|
You must be logged in to rate posts |
|
|
stevo as b4 |
This post is not being displayed .
|
stevo as b4 World Chat Champion
Joined: 17 Jul 2003 Karma :
|
Posted: 23:44 - 10 Nov 2016 Post subject: |
|
|
Sounds like its a proper fucking animal now!
I reckon once you've checked and got the jetting spot on to suit the pipe you'll find your full 30+bhp, and never wear out a front tyre either!
If it's too loony, you might even need to raise the gearing a fair bit, especially at even compared to an MX125, it must weigh naff all!
Looking forward to a vid once it's all set up 100%, as it should be mental and sound proper race bike too!
I hope my new KMX pipe has a similar effect as I'll be chuffed to bits and forget about the expense too. |
|
Back to top |
|
You must be logged in to rate posts |
|
|
binge |
This post is not being displayed .
|
binge Emo Kiddy
Joined: 03 Jul 2004 Karma :
|
|
Back to top |
|
You must be logged in to rate posts |
|
|
331X2 |
This post is not being displayed .
|
331X2 Crazy Courier
Joined: 10 Jul 2013 Karma :
|
|
Back to top |
|
You must be logged in to rate posts |
|
|
binge |
This post is not being displayed .
|
binge Emo Kiddy
Joined: 03 Jul 2004 Karma :
|
|
Back to top |
|
You must be logged in to rate posts |
|
|
binge |
This post is not being displayed .
|
binge Emo Kiddy
Joined: 03 Jul 2004 Karma :
|
Posted: 16:52 - 14 Nov 2016 Post subject: |
|
|
Spent a couple of hours this afternoon fitting the end can and link pipe properly.
It's now got 2 silicone joins rather than one, and I've used a 60-degree
bend in there now.
Reason I've done this is to keep the spanny complete. The last one, I chopped the stinger down to get a link pipe on at a more acute angle.
By keeping the spanny complete, the stinger carries on down towards the rear swing arm, but then I know it's as Arrow intended it to be, rather than shortened, and possibly causing running issues.
Just means I had to pick the link pipe up more, to get to the end can.
It's a nice flowing route though, and the silicone joins are not acting as pipe work. Inside them, the two ends of the steel pipe are touching, give or take a couple of mm.
Up-jetted back to a 165 main, which will give me a good base to work from. Id like to get it semi-correct before paying an hourly rate on a dyno.
Fires up literally on the button. Really can not wait to get it out on track.
https://scontent-lhr3-1.xx.fbcdn.net/v/t1.0-9/15094465_378483432502688_63923928819013499_n.jpg?oh=ff46dec5500432d8f461ff92dcffc97a&oe=588CAF4A
https://scontent-lhr3-1.xx.fbcdn.net/v/t1.0-9/15094237_378483449169353_834005443337916587_n.jpg?oh=35c56b211d62b12098e85cdaf37686e0&oe=58C2336B ____________________ - Honda XL125S - CBR400 NC29 - VFR400 NC30 - CBR400 NC29 - TL1000R - TeeZeR Pit! - Bandit 12 - YZF450 - LuckyMX125 Pit! - Demon X XLR 140 Pit!
- Stomp KZ 160 Pit! - Demon X D-link 140 Pit! - CRF50F Mini-Pit - MonsterMoto 155cc MiniSM - Honda Chaly 150cc - Yamaha 98' R1
- Honda Chaly 140cc - Thumpstar 190cc 4v MiniSM - Aprilia RS125 Pit-Bike - |
|
Back to top |
|
You must be logged in to rate posts |
|
|
Old Thread Alert!
The last post was made 7 years, 135 days ago. Instead of replying here, would creating a new thread be more useful? |
|
|
|