450 Mark 3 engine rebuild and cam change

[machten]

Going though an interesting period learning about the new "starting procedure" required with the G&W cam and Conti pipe. I had the white cam/Silentium pipe nailed - one kick 95% of the time and no kickbacks. They average has declined (for the moment, I hope!). Some experimentation required for cold, hot and (most difficultly) warm.

Kev

[machten]

Been working with a friend who has a 450 Desmo to come up with the best VHB 29 carb config with a Conti style pipe. Given my springer G&W cam and the Desmo B&W are pretty close, we figured we could halve the experimentation time by splitting the options to test. After some playing around we both have had similar issues at about 5300rpm that indicated the needle jet/needle combination as the issue. We'll test in anger tomorrow with both 450's, but Marco's thinking his latest test of his 450 Desmo with the Conti style pipe is running very well through the range with 135 main/50 pilot/ 70 choke/ 60 slide/ V13 needle and 265M atomiser-needle jet.

More tomorrow.

Kev

[Eldert]

Hi Kev

are you sure about the K13 needle ?

a K needle is for the PHF / PHM range . the larger VHB carbies use a V needle ( the smaller ones like the 26 on the 250 scrambler use E needles )

Eldert

[machten]

are you sure about the K13 needle ?

a K needle is for the PHF / PHM range the larger VHB carbies use a V needle

Thanks Eldert,

This is a perfect example of why you should not come home from lunch from your mother's birthday and post a technical post after a few wines.

It was of course (as Eldert points out) a V series V13 needle. I have now edited that above. The other info is correct for what we're going to try tomorrow.

Kev

[graeme]

Hello Kev,
I'll stick my neck out with the suggestion below,,,

You could just fit a PHF 32 and set it to Darmah specs and enjoy riding it?

I gave up on the square slides on my 450's
Only problem is fitting a descent filter that doesn't foul the 450's frame gusset.
Graeme

[machten]

Well, the weather was agin us yesterday with regular showers on the way after a short sunny window, so it was just a suburban squirt and we didn't get the chance to stretch the two 450's legs other than a very brief 80km/h zone. Marco's 450 Desmo ran well in the suburbs and fine up to 6000rpm in the 80km/h zone, so once I can locate my V13 needles in my garage, I'll try the config out on my '74 450 Mark 3.

You could just fit a PHF 32 and set it to Darmah specs and enjoy riding it?

That's definitely a fall back position, Graham. I've got 3 spare sets of PHF32s already built to either 750 Sport or Darmah spec on hand. The VHB worked very well previously though with the white cam and stock silentium, so I'll persist a wee while longer. I've got the Albany Hill Climb in three weeks though, so the clock is ticking.

What manifold did you use to accommodate the PHF and did you disable the pumper?

A shot in a brief sunny moment before the rain set in yesterday with an interluder we figured we'd allow to accompany us..



Kev

[graeme]

Nice bikes,
I used manifolds that I've had for a long time for the RT (no frame issues with a good air filter) and the Scrambler.
The Scrambler is a problem with a K&N or similar due to the frame gusset. I had one of those Malossi screw on bell mouths with the wire gauze that I covered with air con filter media, good enough for now until it gets a rebuild.
In the past I've used a Darmah rubber elbow cut down attached to the carb and had a decent filter inboard facing the battery.
The Desmo has a 250 frame so there's no issue fitting a good filter. (PHF36)
All have the pumps disconnected.
(I just got tired of continually adjusting the square slide carbs and all the starting issues)

Phil Hitchcock has / had blank manifolds some time ago which could be cut down to length and blended to suit PHFs.
About a year ago he was waiting on some more to be cast.

Graeme

[DewCatTea-Bob]

You could just fit a PHF 32

What manifold did you use to accommodate the PHF

[quote= graeme ...
" I used manifolds that I've had for a long time for the RT
and the Scrambler.
Phil Hitchcock has / had blank manifolds some time ago which could be cut down to length and blended to suit PHFs. "

____ It'd be pretty interesting to see any pix showing the particular manifold-fitment (of a 30 ~ 36mm PHF) ! _ Cuz I-myself have found those inconsiderably designed carb.models to be too darn overly-large to well fit within the (somewhat reasonably) limited space left available.


Hopeful-Cheers,
-Bob

[machten]

Excellent, thanks Graeme. I'm going torture myself for a while longer this evening and see how I go.

Kev

[machten]

I guess the other thing worth mentioning is I'm not planning to run a filter for the hill climb...



Some good progress tonight on testing transition to main jet. Nearly there I think.

Kev