+2S Backing Plate Hardware Question

[Hethel_Haus]

I am stumped over here state-side. Trying to get my Dellorto carb set-up back to a standard airbox configuration. I sourced an original backing plate and fiberglass airbox cover from two separate sources, neither of which provided the three bolts (studs?) to mate the parts together. Near as I can tell, it looks like the bolts are either a metric M6 x 0.75 fine thread, or a #12-32 fine thread. I have looked at every hardware store in the area without success for either of these fine threaded bolts.

Could someone please confirm what the correct bolt size and thread pitch is and possibly a source on where to obtain them?

Cheers!
Steve

[rgh0]

standard unf bolts as far as I recall

regards
Rohan

[CBUEB1771]

Mine are 1/4-28 UNF. This is a confusing one as the Service Parts list has the part number as XUCB0532 or 5/16-18 x 2" long, which is wrong.

[Kerryt333]

Hi Steve,
The bolts on my Dellorto set up airbox are 1/4" UNF & are I think 3 different lengths. I 'll go & measure them & get back to you.
Regards
John

[CBUEB1771]

Hi Steve,
The bolts on my Dellorto set up airbox are 1/4" UNF & are I think 3 different lengths. I 'll go & measure them & get back to you.
Regards
John

John is correct, I failed to mention they are of different lengths.

[Kerryt333]

Have just measured them- 1.25", 1.625"& 2.25" long
Regards
John

[Hethel_Haus]

The 1/4" UNF certainly seems reasonable but trying a new bolt on my backing plate doesn't even make it to the start of the threads. I'll have to mic the OD and see if there is enough wall thickness to drill it out and re-tap it. Pretty depressing that this might be the way to go since it was purchased as a NEW part. I guess the LOT in Lotus is living up to it's name!

[cliveyboy]

Steve
Before you start drilling out things.
You say 1/4 UNF will not even start. This sounds like its too big. You mentioned M6 x 0.75.
Have you tried Metric course M6 x 1.0mm. If it has been modified to metric it is much more likely to be that.
If it is M6x1.0 A 5mm drill should go in the tapped hole.
Also when you come to bolt the Dellortos on you may need some metric screws for the tapped holes in the carb mounting points.

Clive