880SFC Dyno results

A mate had one on a KTM 2 stroke 250 endro bike. It had no top end, didnt seem to get on the pipe. It would drone along fine but very far from the way it should have gone. Crispin was looking at them years ago. They still make them and there is a thread on Adventure Riders about them. Seems the altitude blokes who are in Colorado love the way they don't seem affected at 10000 ft.
 
rowdypat said:
 


Actually what I have are Edmonston Industries (Ei) carbs, very similar apparently to Lectron from that era.
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The very same ones I mentioned above, Pat. Lee and I played for hours with them on the Hartley Motorcycles dyno back in the late 70s, and just didn't like them. Same session where we discovered that with K2 needles you can remove the main jet above about 160 or 165 and it will have no effect.

Chris, why did you go with 260 emulsifiers? I'm sure I mentioned 265s - so as we've pointed out, get back to std SF or SFC figures and work from there. I'm fitting FCRs from a GSXR1100, but I'm stripping every jet and needle out of them and going with figures that others have spent hours on dynos working out are right for an SF/SFC motor. Saves me a shitload of time and grief!

Even if your bike feels 'almost right' I'd be looking closely at what you've got. you want it 'perfect'  :D :D :D
 
Piranha Brother 2 said:
Even if your bike feels 'almost right' I'd be looking closely at what you've got. you want it 'perfect'  :D :D :D
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Well, I have put the 265?s back in and have got to the point where I get a slight dull spot at 1/8 throttle on slow throttle roll on. Under power, it?s not even noticeable, just a nice smooth race to high revs.

And starts without choke when hot.

To get to this point I?ve gone from 68 pilots, up 80, with half turn on mixture screws. :o

I presume this is what you have to do with a highly strung motor.

Anyway, an old duck down the road called the cops, so play time is over for the day.

They did all the checks, and my fellow revhead neighbor, a Solicitor, came down and told them I wasn?t upsetting anyone. Apart from that, we are getting on and off showers.

So, I?ll get some 78?s and play with the mixture screws. With a sniffer up it?s pipe.

So close now, very happy.

 
I used to get that when I was doing some tuning, it's not the noise. Its just being in there pissing place, I now going for half an hour and stop. Less grief.And then mow the lawn for 2 hours.
 
Sounding in the ball park, CK, although 1/2 turn on a mixture screw baffles me a tad. I'm tempted to say 50 slide cutaways and smaller pilots would cure that issue, cos that's amonstrous pilot jet (=rich) and a very small needle setting (=lean) but I'm gonna leave it alone ...  :D

Maybe your exhaust is so open it's causing not only a flat spot, but turning your neighbours into enemies!  ??? ??? ???
 
Piranha Brother 2 said:
Sounding in the ball park, CK, although 1/2 turn on a mixture screw baffles me a tad. I'm tempted to say 50 slide cutaways and smaller pilots would cure that issue, cos that's amonstrous pilot jet (=rich) and a very small needle setting (=lean) but I'm gonna leave it alone ...  :D

Maybe your exhaust is so open it's causing not only a flat spot, but turning your neighbours into enemies!  ??? ??? ???
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Q. At 1.5 turns it was way too rich, and rode horribly. Hence the 78?s suggestion and fine tune adjustment at the mixture screw. 75?s and 2.5 turns still needed a little choke to smooth it out.

I?ll put the 78?s in and then back to the dyno guy.

Yep it is loud, but sounds awesome  :D
I was going to get an onboard video, but the cops, weather and the old duck put a stop to that.

Vince, maybe I will have another play, once it?s done a few miles. But as is, very rideable. Even from an almost stop in second gear, it just pulled straight through to about 5,500.



 
chrisk said:
I?m going to get some chocolates, and go down and apologise.
Next time, she might not complain, unless she?s out of chocolates  :P
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She may want more than chocolates .......... she might have been out of what she's seeking for some time!

Play your cards right and you could have your next project funded.
 
Basketcase said:
My old Jawa speedway Dellorto SS1 did not have any jets.

Ju
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  (idea) Does anyone know what the SS1 Stands for? I?ve googled it but come up with no information.

My carbs are marked, PHF SS1 ...... maybe I am trying to tame a race version of the PHF.
 
chrisk said:
 
My carbs are marked, PHF SS1 ......
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Unless they look like this I wouldn't be too worried.

berlinette110-img600x450-1320152719xbedkl14736.jpg
 
Hardly Jim.
I?ve another set, I?m going to throw them on and see what happens. I think they need different stubs, as mine are for rubbers, and the old ones are the clamp on type.
I don?t know if the stubs suit both.
 
Chris, I reckon you'd have to whip up a couple of stubs on the lathe to fit inside the carbs (with the plastic sleeve, as seen on all std Lav Dells) with the mating section at the other end to fit in the rubber stubs.
 
Piranha Brother 2 said:
Chris, I reckon you'd have to whip up a couple of stubs on the lathe to fit inside the carbs (with the plastic sleeve, as seen on all std Lav Dells) with the mating section at the other end to fit in the rubber stubs.
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I?ll get some lathe time this week, was my thought as well. And I think I?ll get some k2 needles, and take the clamp type carbs to original specs. And start all over
 
Dellortoman said:
Make a "Y" shaped manifold for each cylinder so you can bolt all 4 carbies on. Then take it and show it to Clem. He's looking for something he hasn't seen before.  :D
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8) I could show Clem something he hasn?t seen before, but the closest it?s been to Laverda is the back of Laverda fuel tanks.  :D
Having said that, I doubt it would impress him that much anyways. :-[
 
chrisk said:
  (idea) Does anyone know what the SS1 Stands for? I?ve googled it but come up with no information.

My carbs are marked, PHF SS1 ...... maybe I am trying to tame a race version of the PHF.
Click to expand...
Even Eurocarb doesn?t list them in their menu.
https://www.dellorto.co.uk/product-category/dellorto-motorcycle-carburettors-parts/dellorto-vintage-carburettors-and-parts/vintage-dellorto-carburettors/
 
chrisk said:
And I think I?ll get some k2 needles, and take the clamp type carbs to original specs. And start all over
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To save yourself time, fit the K4s to the std carbs! Unless your main jet is smaller than about 160. If you reckon the K4s aren't right you can then try the K2s, but I strongly recommend you start with the 4's. See t be repeating meseff in this thread  :D

Try the needle swap for the dyno runs ... if you wanna play Thomas (The Doubter  8))
 
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