Engineering detail: Africa Twin valve train

[@brianharrigan8821]

People ! Honda knows what is needed ! These are some of the best engineers in the world ! Be happy ! Go ride ! It's taken care of ! Cheers

[@theoverengineer]

Like their Formula 1 team. The one that couldn`t finish a single race. For a year.

[@vietitalia]

@@theoverengineer they have just came back F1 after years. Technology changed and Just let them time

[@markbarber7839]

Thanks for the video. All Honda's of yesteryear had the screw adjustment valve clearance even the 750cc. In those days the value cover had inspection ports so adjustment was fast, easy and economical

[@theoverengineer]

Thanks for watching!

[@AnyMotoUSA]

I actually prefer this adjustment over shims, as a shade tree mechanic I feel this system is a bit easier to adjust than needing to use shims. have been familiar with this valve adjustment in gl1100, gl500 and the whole process usually only takes 10-20 minutes to adjust. I agree that it is a little finicky but haven't had any problems in the older bikes

[@conoliveros1695]

It's easier to adjust so why do Honda charge between £500 to £750 for the 16000 mile service.

[@estebanamador7601]

I love this system, easy to do the maintenance, and the bucket over shim is not necessary because is a "low" rpm engine. Greetings.

[@pilotlang1]

This mod was a great addition to my AT!

[@stimpsonjcat26]

They used the same kind of adjusters in the xr650 and that engine is bulletproof. Also I have read the valve adjustment on the xr has very long intervals under real world use.

[@theoverengineer]

Nobody argued that they are not. Not sure about what`s meant by very long intervals, what can ACTUALLY be read in a 2005 model`s Owners` Manual on page 69 campaigns.hondampe.com.au/Motorcycles/manuals/XR650.05.pdf Honda specifies that valve clearance is to be inspected every 600 miles or 1000km. In real world use.

[@stimpsonjcat26]

They are wrong. I own one and after you adjust them and the engine is broken in. You can easily go over 5000 miles without them going out of spec. The honda spec is more than likely based on the bikes original use which was desert racing. It seemed like you implied that that type of adjuster was unreliable and would wear fast as it has less surface area. That was the reason for my original post. It might scare people away from a great bike.

[@theoverengineer]

Inspecting valves is completely different from and is unrelated to adjusting valves. Just like dental cleaning and needing a filling are completely different & unrelated.

[@stimpsonjcat26]

Well I for one am not going to check them every 100 miles when I know they won't need to be adjusted anywhere near that often. Also my point that the type of adjuster used on the africa twin is a sound and reliable design still stands.

[@theoverengineer]

That`s right. very reliable, light weight, sound design, long history of proven performance, nobody argues that. (*600 miles)

[@rossco88]

I prefer a screw, should be on the intake too, simple ideas if possible are always the best for a adventure bike.

[@rrandydduke]

Dude this is Honda’s Uni cam design and it has been around since 2002 ... this is a low reving engine and shimmed exhaust valves aren’t necessary. Who you to question Honda

[@theoverengineer]

I`m nobody. Just keep paying taxes, watch TV, follow the crowd at lunchtime. Your contribution to society will end with that.

[@rrandydduke]

theoverengineer your way off lol

[@theoverengineer]

my doctor agrees ... Hey, thanks for watching ;)

[@rrandydduke]

theoverengineer take care bud hope I didn’t come across like a jerk 🍻

[@theoverengineer]

All withing good manners and language, no worries I`ll be putting a unicam engine CRF250 Rally through its paces later in 2019

[@zaks9919]

You are all missing the point ., the actual surface area used to push open the valves is about the same .Bucket lifters engage the full width of the valve stem only ,& by the looks of the picture so do these roller rockers ., furthermore the rollers i would bet produce the same surface area do to their rotation .If the engine needed to spin 10,000 rpm for long periods bucket lifters would be a better choice.

[@theoverengineer]

Shims have an extreme surface hardness, they are quenched & tempered, screws are never. Surface are is not even half the story ..

[@SteelJM1]

You can have a SOHC with that valve arrangement. It'll just call for more rocker arms.

[@michsky46]

I saw honda atas with 220k km and no problem. I own one too

[@biophillie]

Interesting.. Thanks!

[@theoverengineer]

You bet!

[@MrKdr500]

unicam is an overhead cam.....it's just Honda's name for their version..... It has one cam and it's mounted over the top of the head which makes it OHC! people are getting dumber with use of internet....

[@ampm9771]

Honda copied this cam system from Moto Guzzi just like many other things that honda copied from other bike makers.

[@mattyb7736]

What a load of crap you are spouting, this system has been around for years, and is a well proven and reliable system. You obviously dont understand the unicam concept and that the exhaust valves by their very nature are subjected to more heat and wear than the inlets ever will. 60,000 km on my africa twin and ive adjusted the exhaust valves once, inlets are still within spec.

[@theoverengineer]

Good insight, thx