griff851
😄 well then, what a bastard. I guess it's pull them apart and and fix the leak in the rear. Why are the wider, longer shafts and different attach rails?
brad black
because they're different i guess.
dudlington
griff851 wrote😄 well then, what a bastard. I guess it's pull them apart and and fix the leak in the rear. Why are the wider, longer shafts and different attach rails?
.
brad black
I guess the injection unit is pumping in fuel and air at the right ratio (?)...................but just too much of both ?.............or ?????
brad black
don't know, those throttle bodies are no longer in it so it really doesn't matter.
marvin
If you can't figure it out I don't know who can! If it was me since I am using the antique 1.6 and burning my own chips would go back and review the that.
brad black
ecu and eprom didn't change, only throttle bodies.
maybe they were bad throttle bodies, i bought them from ebay years ago.
marvin
Brad, Do you want me to send you a set of TB's. You saw what I have. I will be using the S4RS TB's with the pink Pico's and probably will use the 996 set on my S4R engine as I have the standard 996 heads to go on it. But I won't need one of my S4R sets, or the 749 showers (The S4R has the old style TPS)
brad black
thanks, but i'm just accepting it as it is. it's ok, crap at idle, but ok off that and i've got another eprom done to fit when i can be arsed pulling the seat base off again.
rode it today - it's acceptable. not sure if it goes as well as it did, but that's just a memory thing. it's kinda slow. no reason why it should be slower, unless it's a bit fat at wot.
i have some 748 ones as well that i could use, but then i'd really need 748 manifolds and 748 heads. or machine the 748 ones to be like 916 ones.
patrick
Hi dear 851 friends
A little bit in late in this discussion, it's a pity, my old back and a new discal hernia are the responsibles...:-)
I was obliged to set a new upper couple of brackets to be able to run my 851 90 a little bit.
Fortunetely or unfortunetely i have a son who recently got the full license (more than 47HP in france)
I let you imagine witch he choices to take, between the CBR 250 and 650, and the 851...
When I read this post today i have been suprised about (bad) Brad experience and disappointed for him
(All things i've done, i learnt from him)
For the same reason than Brad, I mount (in the order):
Some 1991 stronger valve springs, the 1990 are definitively bullshit; mine never runs correctly under 4000 rev.
A S4R throtle body, a full 916 throotle and cable,
An home made chip (basically, leaner at low revs until 5000 and recently richer upper, to safe the cam timing, Magnetti Marelli confirmed me a few years ago the injectors pulse the same fuel amount after doing a test myself, so it was easy to play with the maps.
A 108/108 diagram (not exactly the Brad specs but approx' due to the offset keys i could have)
It runs smooth at low revs, iddles near the perfection 1000/1100, and it responds much more better!
For proof, my best friend who runs a stock 1991 said: yours is a bomb! Why?
Definitively too difficult to explain to a non-mechanic guy.
Cam timing for sure is the main cause of the power respond feeling.
Just remembering i used the new fuel regulator not the settable old one.
If i remember others i will post again
If you need more details don't hesitate
Drive safe
Patrick
patrick
Hi dear 851 friends
A little bit in late in this discussion, it's a pity, my old back and a new discal hernia are the responsibles...:-)
I was obliged to set a new upper couple of brackets to be able to run my 851 90 a little bit.
Fortunetely or unfortunetely i have a son who recently got the full license (more than 47HP in france)
I let you imagine witch he choices to take, between the CBR 250 and 650, and the 851...
When I read this post today i have been suprised about (bad) Brad experience and disappointed for him
(All things i've done, i learnt from him)
For the same reason than Brad, I mount (in the order):
Some 1991 stronger valve springs, the 1990 are definitively bullshit; mine never runs correctly under 4000 rev.
A S4R throtle body, a full 916 throotle and cable,
An home made chip (basically, leaner at low revs until 5000 and recently richer upper, to safe the cam timing, Magnetti Marelli confirmed me a few years ago the injectors pulse the same fuel amount after doing a test myself, so it was easy to play with the maps.
A 108/108 diagram (not exactly the Brad soecs but approx' due to the offset keys i could have)
It runs smooth at low revs, iddles near the perfection 1000/1100, and it responds much more better!
For proof, my best friend who runs a stock 1991 said: yours is a bomb! Why?
Definitively too difficult to explain to a non-mechanic guy.
Cam timing for sure is the main cause of the power respond ,k feeling.
Just remembering i used the new fuel regulator not the settable old one.
If i remember others i will post again
If you need more details don't hesitate
Drive safe
Patrick
brad black
i'm way too lazy to replace the closing springs on an engine in the chassis. i don't need that sort of agro. and too lazy to pull the heads. so it'll stay as it is i expect.
patrick
I understand you haven't only one to look after! In my case , only one.
i spent so many hours of settings, disassemblies, mappings, trials etc...that when i discovered it was the main cause of this crappy running at low revs, i throw myself on the heads and these poor springs.
I operated on the bike, it's not easy but faisable.
So you have to drive it like a Superbike, in fact its first target, from 5000 rev😊
Mine now is so nervous and happy to hight rev with the heavy springs and overall the cam timing, that I decreased the red zones (fuel and ignition cuts) at 9500 revs to secure the crankshaft.
brad black
i'm sure we spoke about this years ago. i was a little concerned as to the reliability of the 1.5mm collets and the heavier springs. but really, laziness is the bigger issue.
i did make a tool a while ago for flipping the spring tails in with heads on engines. funny, some days it works with no effort, some days it's still a nightmare
i rode it the other day with all its low speed crankiness. i'm sure it's going to shit me endlessly until i do actually fix it.
patrick
Yes Brad we spent a lot of discussions on this 90 bike!
I was confident with the stronger valve springs and small rings couple, because my friend 91 one had it (i saw the springs on it for sure, and the valves are the sames in 91)
For information, after a few thousand of kms including a few harder uses, on track demonstrations (the reason why i set the cuts at 9500 😷😉, i recently checked and set the valves plays, the 1.5 rings haven't (yet...?) shown worrisome traces of crushing or wears.
Hoping again a long life to it ,and yours; now 67000 kms, no signs of weakness.
Pat
brad black
old vs new.
Mr.R
On stripping down quite a few early heads with the 1.5mm half rings, I've found several of them broken.
But I've never found any of the later 1.75mm half rings broken, although they do crush down.
I now use MBP Collets and have never had one break or crush down. 😁
Steve R
brad black
computer says i've bought 215 1.7mm collets in 10 years, a few replacing lost ones.
i see quite a few broken 1.7mm, esp on things that get revved.
i found 91 models had heavy springs and 1.5mm collets, so that put my mind at ease a little. altho they also had the 009b eprom, which makes me wonder how they ran at low speed.
brad black
i did a piece for my blog about the spring change, as i hadn't done anything there for months. i'm too lazy to replicate it anywhere else due to having to put the images in everywhere.
https://bradthebikeboy.blogspot.com/2018/12/closing-rocker-spring-change-on-851.html
econti
brad black wrotei did a piece for my blog about the spring change, as i hadn't done anything there for months. i'm too lazy to replicate it anywhere else due to having to put the images in everywhere.
https://bradthebikeboy.blogspot.com/...ge-on-851.html
You'd be the one to know! ST4 engine in late 888 strada, what airbox will work? 888?
brad black
everything should just be normal 888.
