RZ/RD 350 & Misc. 2-Stroke Tech BBS

Technical Forums for Two-Stroke Nuts
It is currently Sat Sep 23, 2017 8:24 am

All times are UTC - 4 hours [ DST ]




Post new topic Reply to topic  [ 5 posts ] 
Author Message
PostPosted: Thu Jul 13, 2017 8:40 am 
Offline

Joined: Sun May 22, 2016 8:27 am
Posts: 35
Hi guys,

Finally passed the engine @ the dyno this weekend, i was racing at Magny-cours for the RD500 track weekend.
Off course, this curve is rear wheel power on 5th gear, add 20% for engine HP.

Video here ==> https://youtu.be/GsoJgAIYiz8

I passed some Tz and 500 RD/RG easy so i think this dyno is really pessimist according to the owner.
I'm really proud of my setup and work, engine have plenty of torque, but know i'm looking for a way to improve mid-range power to boost the range between 6000 and 8000 because this range make the engine very hard to ride specially out of corner

So if any of you have some tips i'm listening

Image


:smt023


Top
 Profile  
Reply with quote  
PostPosted: Sun Jul 16, 2017 1:51 am 
Offline

Joined: Mon Sep 27, 2010 7:21 pm
Posts: 446
Location: Wellington New Zealand
Yeah my 496 has a dip there. I pulled the ypvs fuse and got a bunch back. Hold on you say. Well mine is converted to servo motor, sorry no more kits being made. My next step is program later PVopening when iI wire in the Ignitech that'sjust arrived.

So you could try a little more preloaded on your power valves. Perhaps the air bleeds which are drilled out jets might be made smaller to delay PV opening.

Make sure the valves in closed are close to piston.
Feed some more advance at the lower end, it should be safe as you haven't got much pressure going on with combustion.

Try leaner needle or position, it may just not be able to recover from a dump of rich gas when you whack it open on the dyno.

_________________
496 Cheetah. TSS PVs, PWK35s, Zeeltronics ign, RGV(ish) chassis


Top
 Profile  
Reply with quote  
PostPosted: Mon Jul 17, 2017 4:30 am 
Offline

Joined: Sun May 22, 2016 8:27 am
Posts: 35
Sorry, it's not a cheetah but a cheetah CUB, there is no valves :smt003

But i'm assuming it is way too rich, changed jet from 170 to 165 and it still bit too rich... Engine should be 95hp with the good jetting
I'm going to lean the needle a little too
Timing is already very high from 3k to 6k (about 30°) but i can gadd a little more


Top
 Profile  
Reply with quote  
PostPosted: Mon Jul 17, 2017 5:35 am 
Offline

Joined: Mon Sep 27, 2010 7:21 pm
Posts: 446
Location: Wellington New Zealand
They get a little optimistic with their power claims I understand.
Yeah 30 isn't mild. I do wonder how suitable the air correction jets (well, drilling) are at producing a suitable curve with pwks.

_________________
496 Cheetah. TSS PVs, PWK35s, Zeeltronics ign, RGV(ish) chassis


Top
 Profile  
Reply with quote  
PostPosted: Tue Jul 18, 2017 4:35 am 
Offline

Joined: Sun May 22, 2016 8:27 am
Posts: 35
Yes, a lot of riders are using very very optimistic dyno since they have 105 HP at the wheel..... :smt015
And even if true, engine is unrideable.

Stock PWK idle jets were way too rich, i'm 50 now and still bit too rich but it's to prevent seize on the gaz throttle closing.

If you see my friend Etienne post : viewtopic.php?f=5&t=6593&p=116934&hilit=etienne#p116934
His bike is one of the most powerful i know and it is "only" 80hp like me... but i has much more mid range :smt001

I really would know too what needle and drilling is the best for this engine mid-range power


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 5 posts ] 

All times are UTC - 4 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 4 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group