RC India

Hey guys, i have an ASP 46 engine, i was assembling the carburetor, and i overtightened one of the screws, and now it is no longer getting tight. So what should i do to tighten it again? Do i use 'jugaad' and use teflon tape and epoxy on that screw?? Or something else?

Pls. Dont suggest getting a new engine, as i am on a really tight budget.

A very basic way people use in this condition is using small sewing thread in the thread of screw and then try to push it in.

Can you pls. Elaborate, i didnt get u

use the sewing thread. the thread which is used for sewing cloths. you will get whole hardly for 2-3 rs . wrap it in the threads of screw for packing. then push the screw in engine and tighten up. you will get good hold from it. This trick is used by all plumbers to fit pipe. you dont get leakage as well...

But plumbers pipes dont get hot, carburetor will get hot

that is the only reason i asked you to use thread because if you use any thing which is made up of plastic or rubber then it will melt and you wont be able to open your carburetor again ever. another option is go to workshop where people work on LATHE machine they have a proper option for this they can surely help you with this.

LATHE guys are saying we cant do anything

Then only that thread wala Jugaad will work i think. atleast you can try that.

If there's option use a longer screw along with a nut to hold the screw on the other side. Not sure about your carb but this works on automobile carbs. And at times lathe guys do also fill up the gap with aluminum weld and then drill a hole and retap the threads.. ask them if they can do this.

yashodhanp same thing happened to my ASP 52 about a month ago! what i did was, i enlarged the hole for 4.2mm than inserted the 3mm helicoil! now i am using same carb screw! so try to find where you can get helicoil and helicoil insert tool! bit hard to find though ,but its a solid and permanent solution!

Best of Luck. :thumbsup:

Whats the price for that??

There is a manufacturer of helicoil in kolkta, but they wont sell few pieces

i don't know exactly!may be 50 :Rs: for helicoil and 250 to 350  :Rs: for simple tool! but you need to have experience to deal with! just try where they do helicoil inserting in your city ! you can check with automobile shops or bike repair centers where often they repair damaged threads on cylinder heads!

check with hardware shops who deal with all types of fasteners and screws!

http://www.heli-coils-india.com/product-size.html

Pls. Help me in telling me which one i have to buy

go for M3,usually all screws in engines are M3!

You can try filling up the inside edges of the hole with brazing. YOu can find it at places close to Lathe workshops. Lathe guys get their carbide tool brazed. Once brazed...It is very easy to Tap this with M3 Tap. Tapping is a process of Cutting internal threads by passing a tool called TAP. This is done by rotating the tool by hand in the hole. http://en.wikipedia.org/wiki/Tapping_(threading) (http://en.wikipedia.org/wiki/Tapping_(threading))

This should work.

Shreekant

The easiest fix is to just tap the hole for 6-32 thread and use a 6-32 screw, have fixed my and many other's engine and other items where it used a 3mm screw and the user engaged hands before engaging brains   

Manish's advise is good. But suggest you go metric. Jugaad options don't work on carbs, because the length of threaded portion is only a couple of mm.it will fall off due to engine vibration and you may loose the carb.
Drill the hole with a 3.2mm drill bit and tap it with a 4mm tap. carefully, the alloy is soft. Then use a 4mm screw. A local machinst can easily do it. Or you could for a total of around Rs. 150. Practise several times on a scrap of aluminium until you are confident before doing it on the carb. Also remove every bit of metal burr before using the carb
The other suggestion of putting a 3mm screw right through and and bolt it on the other side may affect carb function as the space just under spraybar has the bolt running across. but it is an easy fix.
good luck
regards
Avijit

Doc yes, metric is easy and locally available, but in my experience due to coarser threads on the 6-32 it holds better and is easier to work than finer pitch threads on 4mm