750 GT 29mm Dels & Airfilter

[Jed]

In getting Isabella ready for her first Oz rego I took her a km or two on Sunday to see what happened. Boiiinnnnggg. She's a bit like a rubber band with a long 1st gear, heavy crank and plenty of torque. She reminded me of an old 500 G80 Matchie I had a few years ago.

Anyway I made sure there was plenty of fresh oil in the rocker box and that the plugs were clean and gapped and points were okay and off I went. I don't think I would have got over about 4K revs or over 4th gear in the short journey. On a steady throttle she was fine but wouldn't accelerate unless the choke was put on to about half and then she pulled relatively cleanly.

Clearly not right. I've not paid too much attention in and around the carbs but here's a few things I need help with.

1. Ah, well these probably didn't help between the carbs and the airbox... I've ordered some new ones.

2. The airfilter is not a paper one but this... a sponge under the battery box (sorry about the fuzzy pic, my camera didn't like it in there.)

I'm not too sure what to do with this. I'll get it out undamaged then what? Wash it, oil it? Any advice gratefully received.

3. Finally the carbs themselves. I figure I should get them off and dismantle them and clean them in the first instance so they are now off and on my bench. Again any advice on how best to do this gratefully accepted.

Thanks all.

Jedzo

 

[Cyriel]

The Rubbers from carbs > Air filter and air filter itself are not so important, unless the air is completely blocked.

First check the O-rings, Gasket carburettor isolation and inletmanifolds, which must be in good condition.
Then check the carbs for the correct sizes of nozzles and worn parts.

Finally clean the carbs and adjust.

 

[jlo]

Sorry Cyriel, I don't agree as air filter is VERY important on these engines. I had one (brand new OEM) on my 1968 GT, that I have finally removed (open stacks now) as it was very restrictive. It is really day and night with and without the filter.

On the other hand, the carbs have to be fully dismantled, cleaned, seals and gaskets changed, needles and needle jets checked and preferably replaced. The problem is that new needles for the VHBs seem to be very rare nowaday.

 

[sfcpiet]

Correct V3 needles and neddle jets currently available in Europe.  Drop me a line!  Only a small repro batch been made... sorry, no slides!  Haven't been available for several years.

piet

 

[jlo]

Correct V3 needles and neddle jets currently available in Europe.  Drop me a line!  Only a small repro batch been made... sorry, no slides!  Haven't been available for several years.

piet

I'll contact you off list, may I order 2 dozens? 

 

[Jed]

Correct V3 needles and neddle jets currently available in Europe.  Drop me a line!  Only a small repro batch been made... sorry, no slides!  Haven't been available for several years.

piet

I'll contact you off list, may I order 2 dozens? 

Leave some for me JLO 

 

[The USA 1968 650]

V-3 needle I know were NOS one are $4.00 + shipping there are many too be had  .I had to put new one in the 650 the old ones were wore out
slides they are the same cut as  Aermacchi Harley's jets too the same  not hard to find.you have too know were to look..
As far as that air filter run it saves the engine,the 650 filter had been wrapped in foam like that ,you can get A Uni Filter flat piece of foam big enough to cover it zip tie it one and oil it ,that thing was paper and they pulled the dirty paper off "don't lose that air filter frame don't trash it"will work fine you can order it from A motorcycle shop will be about $14.00
air cleaner boot there are repo ones out there if you take care of them will last along time
if some needs V-3 needles NOS "the real thing" not repo contact me we will do by pay pal
if you don't run that air filter you will ware out slides way to soon" all that dirt grinds on that stuff and it will be trash" and other parts and the like pistons "you just can't find 1968 650 Laverda pistons or A ring set if someone has that stuff I need to know about it" not cheap to fix
will put A pic of how I fix the 650 air filter .it runs A short Paper filter and work vary well ,the bike runs fine with that small filter on it, pulls like A train "A 650 train".

 

[Jed]

V-3 needle I know were NOS one are $4.00 + shipping there are many too be had  .I had to put new one in the 650 the old ones were wore out
slides they are the same cut as  Aermacchi Harley's jets too the same  not hard to find.you have too know were to look..
As far as that air filter run it saves the engine,the 650 filter had been wrapped in foam like that ,you can get A Uni Filter flat piece of foam big enough to cover it zip tie it one and oil it ,that thing was paper and they pulled the dirty paper off "don't lose that air filter frame don't trash it"will work fine you can order it from A motorcycle shop will be about $14.00
air cleaner boot there are repo ones out there if you take care of them will last along time
if some needs V-3 needles NOS "the real thing" not repo contact me we will do by pay pal
if you don't run that air filter you will ware out slides way to soon" all that dirt grinds on that stuff and it will be trash" and other parts and the like pistons "you just can't find 1968 650 Laverda pistons or A ring set if someone has that stuff I need to know about it" not cheap to fix
will put A pic of how I fix the 650 air filter .it runs A short Paper filter and work vary well ,the bike runs fine with that small filter on it, pulls like A train "A 650 train".

Good stuff to know, I appreciate. I've got some Unifilter sheet and some filter oil so I was going to get the old one out this weekend and set up a new oiled one. I've also got some velocity stacks as well as new boots coming so I'll have both options, filtered or open. Later this week I'll dismantle the carbs & get a first look at the needles, jets, gaskets, o-rings & ports.