Need some advise

[zak_62]

Hi all~
I posted here before about the abiding idle mixture screw I had. Now I have the carb removed and I have soaked the whole thing in aceton for hours and throughly cleaned up the threads, I found many of the threads were sheared and the screw still refuses to go in smoothly. I am thinking about getting a good used carb to replace it, but nevertheless, a pair of used turbo carbs are incredibly difficult to find.
I called a few used parts supplier and the best they can offer is the DHLA45 from N/A Esprit. Will I be able to convert the N/A use DHLA 45 to a Turbo use with the replacement of my old Top Cover and jets?
What do I have to watch out for?
Thanks.
Isaac

[dr.hess]

Get a tap and die set for starters and see if you can clean up the threads. Only eight or ten bucks from Harbor Freight. Next, Permatex/Loctite make a thread restore kit that basically fills the threads with epoxy and is listed as stronger than the base metal.

Dr.Hess

[lotusguy]

zak_62 said:

Hi all~ I posted here before about the abiding idle mixture screw I had. Now I have the carb removed and I have soaked the whole thing in aceton for hours and throughly cleaned up the threads, I found many of the threads were sheared and the screw still refuses to go in smoothly. I am thinking about getting a good used carb to replace it, but nevertheless, a pair of used turbo carbs are incredibly difficult to find. I called a few used parts supplier and the best they can offer is the DHLA45 from N/A Esprit. Will I be able to convert the N/A use DHLA 45 to a Turbo use with the replacement of my old Top Cover and jets? What do I have to watch out for? Thanks. Isaac

Zak,

First off, if the screw will go in, that's all you need, you won't be making a habit of unscrewing them. But, if it needs addressing, as suggested, get a set of taps and carefully re-tap the holes.

For ALL your Dellorto needs, your only source should be EuroCarb LTD. out of the UK www.dellorto.co.uk . EuroCarb boasts a greater inventory of Dellortos and Dellorto parts than anyone else in the world, including Dellorto. Contact Matthew Cooper at EuroCarb - [e-mail].

FYI, the carbs on the Turbos are Delllorto DHLA 45 M's. The 'M' designation denotes the Turbo carb which is essentially the same as the 45DHLA, except that it uses butyl rubber gaskets instead of paper ones so that it can be pressuried to 12PSI. So while a DHLA will work, you must substitute the 'M' rebuild kit in place of the stock paper gasket kit. Happy Motoring! ...Jim'85TE

[Esprit2]

Zak,

Inspect the other three idle mixture screws on your engine and select one with good, clean threads. Try installing that one in the bore formerly occupied by the bad screw.

If the good screw goes in and seats properly, then the problem is isolated to the bad screw. Replace it.

If the good screw will not go in and seat tightly, then the threads in the carb body are probably stripped as well. Talk to Matthew Cooper at Eurocarb about repair possibilities, but I'm not aware of any. Sorry.

I have not used any of the thread repair epoxies like the one Dr. Hess mentioned. High torque load is not an issue here, so they may work. The only issue I see off hand is getting good coverage down in the bore without pushing any epoxy ahead of the screw and plugging the port. Hmmm... perhaps "painting" the inside of the bore with the thread repair epoxy followed by chasing the threads with a tap.

Good luck,

Tim Engel
Lotus Owners Oftha North
Minnesota, USA