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Dum Dum Bullet

Dool2 said:
I will not revisit the Valve Lapping discussion/Heated debate from before, But a thinner Seat is better!

P = F/A
So it would be silly to argue with Physics:)
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Personally, I don't see any point for heated debates over what someone else wants to do to their own motorcycle. (y):cool:
Of course when I mentioned above about modding the J-Series being an exercise in futility, I should have clarified better. I meant for "off the shelf" plug-and-play stuff. Not full-on engine mods like big bore kits, custom porting, and cams. I'm totally immersed in what you're doing (I miss building like this. I'll live vicariously through your work!), and look forward to not just the baseline stock vs custom built dyno runs, but to me, more importantly how the Butt Dyno reacts......especially with that custom cam maker in the soup now. :):unsure:
In my youth, I radically ported and stuffed the crank on my Husqvarma. It was fantastic on the MX tracks, but became simply awful for any trail riding.:rolleyes: That's why it now sits as Shop Art.
 
I still think it is an exercise in futility, but am 100% on board and my futility parts have been needing a good workout for a while now.

This is the sort of stuff we did to our 'stock' VWs back in the day, port matching, deshrouding, oversized injectors, all the stuff you'd never see from under the hood. The VTEC Honda guys had a saying in my area, "You can never sleep on an 8-valve 'Dub. The worse it looks, the more embarrassed you'll be. "
 
Looking really good on those ports. Air will flow through there faster than grease through a goose.

That baseline chart really shows how amazingly ridable these engines are right from the factory. Flat torque straight across, dipping only slightly before the HP curve comes in to continue working on the task with another long, flatish curve. At almost any RPM you have all the grunt available, which makes for almost seamless power delivery. The numbers could be higher, sure. But the curve itself is top notch, kudos to RE for the J series.
 
Need it like you need a hole in your head
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New Head and Cylinder.
Cam fitted, 411cc overbore.
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I used 2 base gaskets that initially measured 1.1mm
Will do a compression test tomorrow.
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Spot the difference.
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Took some Measurements
20250126_072007.jpg
500cc will not drop in
So 477cc will be the limit.

So far all good, feels livelier ;)
 

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More surprises
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Air filter cover removed,
And installed.
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Bike rides like a hooligan version of the OEM and should improve as it runs in.
Only got in a 45km ride that I regularly do and the difference was, I didn't get that Lacking of Power feeling of the 350!
Only 60cc and a Camshaft, fx etc.
 
Dool2, two questions.
I noticed when I did the valves on Pyle last week, I was shocked to see the cam gear is fully adjustable! (y):D Have you messed with that at all, and where did you set it with the new cam?
Secondly, I notice the J350 has that same damn rattle my 411 had, prior to changing the cam in my Scram. Does the J350 also have the decompressor on the stock cam and did the new cam also have one?
Many thanks for your input and tech knowledge. :)
 
Dool2 said:
I set the Cam timing by the Book, the TDC set tool and the the Cam set tool, quite boring actually.
No de-compressor so you will need to look elsewhere for the noise.
Click to expand...
I just think it's a patented RE noise that they stuff into every single. :ROFLMAO:
Ditching the decompressor on the 411 "helped", but didn't eliminate it completely. My ear is telling me it's just the natural sound of a long stroke, air cooled motor.
 
2LZ said:
Dool2, two questions.
I noticed when I did the valves on Pyle last week, I was shocked to see the cam gear is fully adjustable! (y):D Have you messed with that at all, and where did you set it with the new cam?
Secondly, I notice the J350 has that same damn rattle my 411 had, prior to changing the cam in my Scram. Does the J350 also have the decompressor on the stock cam and did the new cam also have one?
Many thanks for your input and tech knowledge. :)
Click to expand...

What clearance did you use? I set mine at 3 and 5 thou, it is quiet if nothing else.
 
Saw this thread for the first time today. Nice work!

Did you compression test before any work? And did you not lose a lot of compression with the 'widening' of the head?
 
Dool2 said:
What clearance did you use? I set mine at 3 and 5 thou, it is quiet if nothing else.
Click to expand...
Went with "Spec"
Intake: .08mm
Exhaust: .18mm

It's not a valve rattle, more of a piston slap-type of sound. Maybe I notice it because it's so steep here. I'm either on the throttle or on the brakes.
I posted about it in the himi forum with a vid but current;y cant locate it to attach. I'll keep searching.
Long story short, obviously it's nothing to worry about. Just more of a curiosity, at this point.
 
smilespergallon said:
2LZ, I still think you're hearing the reflection off the back of the intake valve, try the stock snorkel and see if that mutes it for you.
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I'll give it a shot on the Scram I still have the stocker. Pyle came with the DNA intake installed. Now if I can only get over this "cold from Hell" and make it back out to the shop again........ I love watching black and white Westerns but five days now...come on. :mad::rolleyes:
 
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