[REpozer]

My intake push rod fell off . To avoid this from happening again , I purchased some Hitchcock Push Rod Adjusters that claim to have clever British engineering to help solve problem. They are currently in the mail/post.

Has anyone had this happen on an AVL engine before? What did you do?

[tooseevee]

My intake push rod fell off . To avoid this from happening again , I purchased some Hitchcock Push Rod Adjusters that claim to have clever British engineering to help solve problem. They are currently in the mail/post.

Has anyone had this happen on an AVL engine before? What did you do?

      Hasn't happened to me yet, but as you all know, my '08 AVL has very low mileage.

        The cups on the OEM were never deep enough. I purchased a set of Hitchcock's adjusters at the same time ACE was doing my head. And then what did I do? Of course, I forgot to install them when I put the head back on

   And there they sit on the shelf for the next owner.

[Adrian II]

It's one of the puzzling aspects of the AVL/McGuigan redesign. The Redditch/Chennai iron barrel tappet and adjuster arrangement was and still is fine. Why change it? Apart from the AVL adjuster being more prone to coming adrift, the tappet stems themselves have been overly slimmed down and are weaker as a consequence.

A.

[allanfox]

I have the deeper cup Hitchcock adjusters on mine, nothing has ever happened so I guess they work, a couple of weeks back I had it at an indicated 100mph + and all was well, guess if they are going to jump off that would be the point! I have also fitted iron bullet cams so needed to lose the valve lifter top hat and mechanism to get it all in.

[tooseevee]

I have the deeper cup Hitchcock adjusters on mine, nothing has ever happened so I guess they work, a couple of weeks back I had it at an indicated 100mph + and all was well, guess if they are going to jump off that would be the point! I have also fitted iron bullet cams so needed to lose the valve lifter top hat and mechanism to get it all in.

     I, too, have removed the so called "decompressor" mechanism on my '08 AVL. It was more or less useless right from the factory anyway.

      How do you find kick starting with no decompressor?

        Mine is a bit tricky & difficult to get just at that right sweet spot just over TDC with 9.8 comp. ratio. I only weigh 120 & I can almost nudge the kicker all day long without it moving and THEN it goes too far because the comp pressure is so much & I have to come up again.

     My kick-only harley was easier. Even in the dead of winter it was 3 easy kicks; 2 with the key off & another with the key on.

     Once the Enfield is warm, however, I can just kick it any old place & it starts immediately.

      And just breathe on the starter button & it's running.

[Paul W]

I was offered the chance to try kickstarting an acquaintance’s Electra X, which he’d only recently bought.

I used the valve lifter, which I found quite tricky and needing a lot of effort, compared to the decompressor valve on my kick start only 350 Electra, even though mine has a 10:1 piston.

I got it going after a couple of kicks though. I think he was quite impressed. I asked him if he used a different technique and he said he’d never tried kickstarting it and always used the electric starter!

[allanfox]

     I, too, have removed the so called "decompressor" mechanism on my '08 AVL. It was more or less useless right from the factory anyway.

      How do you find kick starting with no decompressor?

        Mine is a bit tricky & difficult to get just at that right sweet spot just over TDC with 9.8 comp. ratio. I only weigh 120 & I can almost nudge the kicker all day long without it moving and THEN it goes too far because the comp pressure is so much & I have to come up again.

To be honest it is pretty easy, but I have an EFI piston fitted so dropped the comp a little bit (faster for it too) I follow the Paul Henshaw described method to avoid kick back, so as I have lower comp and am nearly twice as heavy as you     those combined making it a relatively easy kicker!  Without fail 99.9% it is a first kick bike when cold, Amal carb with tickler, a handy thing when kicking it up.

[tooseevee]

I used the valve lifter, which I found quite tricky and needing a lot of effort, compared to the decompressor valve on my kick start only 350 Electra, even though mine has a 10:1 piston.

      The original AVL "decompressor" was & is as useless as tits on a suitcase.

       When you pull on that lever you are not actually "lifting" anything. All that lever does is jam a cam against the pushrod so that when it lifts by the engine turning over the pushrod is not allowed to come back down thereby holding the exhaust valve open.

     You can pull on that lever all day long & unless the engine is turning over you are not decompressing the cylinder or anything else.

    It worked, well, "OK" for electric starting, but very tricky to use for kick starting; too many things going on.

[Paul W]

Yes, seems to me that I had to kick the one I tried over compression anyway before the valve lifter caught it on the next time round. A proper Decompressor valve works on any stroke, much more logical.

[tooseevee]

Yes, seems to me that I had to kick the one I tried over compression anyway before the valve lifter caught it on the next time round. A proper Decompressor valve works on any stroke, much more logical.

      Exactly. The "decompressor" & the very weak sprag clutch electric start bodge were the two worst weak spots of the AVL.

        That plus too many owners. oblivious to the danger, too many times cranking on the electric start with a worn down battery which was exactly what was necessary to cause kickbacks from that first BTDC spark as the piston was coming up & the total destruction & jamming up of the sprag clutch.

[El Saif]

My 2004 Royal Enfield Thunderbird 350cc AVL has done 17,034 kms.

It is a standard unmodified AVL model with only a kick start. It has a front disc brake which was a Rs 500 option from the factory.

I am aware that Royal Enfield engaged AVL, an Austrian company to design a new head and barrel to pass emission regulations. Royal Enfield also engaged Ricardo Engineering, a British company to design the new 5 speed gearbox.

Who is McGuigan?

I have no problem using the kick start. Most of the bikes that I have owned have been kick start only bikes.

[Adrian II]

Dr Stuart McGuigan was sub-contracted by AVL for the re-design of the Bullet engine.

He used to work at Shrivenham Military College in the UK where he also developed a diesel version of the 500 Bullet in the mid 1990s for possible military use. Unlike commercial diesel conversions of the Bullet which fitted an agricultural diesel engine in the Bullet frame, this one kept the crankcases and gearbox of the standard Bullet engine but with a custom crankshaft and, I believe, a 4-valve cylinder head. The engine and gearbox were fitted in a Cheney scrambler chassis, and the bike was good for 85mph. I'm not completely sure but I think this one was kick start too, so obviously a good decompressor was needed.

A.

[El Saif]

Thanks for the information about McGuigan.

Just conjecture, but perhaps McGuigan was trying to compensate for the different rates of heat expansion between the old cast iron barrels and the later AVL alloy barrels and heads.

[Adrian II]

It still has steel tappets and aluminium alloy push rods. My uninformed guess is that lightening the valve train was an attempt to help the engine rev more freely - one of the claims made for the aftermarket Samrat rockers for the iron barrel Bullets. Leaving that part of the engine alone would have been better.

Again the exhaust valve lifter was less effective than the old Bullet's decompressor, and it cracked my tappet cover on my old Electra-X! For the 500 AVL cylinder heads there's plenty of room to machine out and retro-fit the old Bullet's decompressor valve, however that might not be possible or even necessary on the 350 AVL.

A.

[Paul W]

Intrigued by the statement that SAMRAT ally rockers could make the engine rev more freely! The ally bits are the rocker mounting blocks which don’t move so would have zero effect on revs. The rocker shafts do look a bit better made and lighter, but there’s plenty of scope for lightening the standard items on a DIY basis using a grinding wheel and file, as I did mine.

[Adrian II]

The AVL rockers are quite heavy-duty compared to the IB's Samrats, though they look better made than the factory OEM rockers.

A.