7 replies to this topic

[Sussex_pete]

Came across this "issue" when I was preparing to start installing the ancilliaries to the engine. I was planning to replace the clear plastic dizzy cap, but then realised the complications that would ensue. Now flummoxed about my way forward, without resorting to replacing the original parts. Anyone got any thoughts?

 

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[Homersimpson]

Looks like a thread has stripped and has been drilled and tapped to a larger size, I would say this is fairly common way of overcoming this problem otherwise the distributor would have been scrap.

 

If it were me I would just fit a new distributor cap with the existing screws and drill the one side of the cap out slightly larger.

 

If you want it to look perfect then just order two new cap head screws and drill and tap the other side of the distributor to match.

[alex-95]

As above, Common for them to strip threads. You could heli coil it to the original size or drill the other side and tap it the same and drill the cap out.

[dyshipfakta]

I personally would leave it and just take the hole out a tad on the dizzy cap. Will take afew seconds

[1984mini25]

As above.

 

But, Having had the same issues were both threads stripped on my dizzy, and as a 'temporary fix' tapped the standard m5 threads out to m6 and drilled out the dizzy cap to suit after a number of reasons I eventually replaced the entire dizzy.

 

The reasons were. You might think it's quite simple to just enlarge the holes in the dizzy cap, but nope some dizzy caps are made of brittle plastic that shatter if your not careful (normally when drilling/enlarging the second hole) scrapping a brand new and now useless part.

 

I also had an issue were the spring in the centre part of the dizzy cap had corroded and fallen to bits (cheap crap from euro car parts). But what should have been a simple remove 2 screws and replace with a new cap wasn't possible as i was 30 miles from home, so even if i could have found/bought a new cap i wasn't then able to enlarge the holes in able to fit it.

 

And lastly, I did buy (only a fiver) an m5 helicoil kit in the hope of resorting back the tapped out m6 threads. Unfortutaly the m5 helicoil uses a fine outer thread and the standard m6 thread is course, and although the m5 helicoils will fit if forced they just don't work. So I ended up having to completely replace the dizzy, but the kit wasn't entirely wasted as I drilled out the good m5 threads on the new/2nd hand dizzy and fitted the helicoils anyways as they are stronger.

 

I've also ditched the 2 Philips head screws and replaced them with two allen head bolts, as it's much easier to remove those with an anllen key as apposed to having to filly remove the front grill and use a screwdriver.  

 

Also don't use a bolt that is two long on the vacuum advance side as it jams up while driving, giving limited, none or whatever its stuck at constantly. 

Edited by 1984mini25, 30 December 2018 - 12:52 PM.

[Ethel]

M7 bleed screw, ideally brass - as an alternative to a helicoil

[Sussex_pete]

Thanks for all the feedback guys and have to agree that the easiest solution for me to move forward is to enlarge the appropriate hole in the dizzy cap and fit a new M6 bolt. One thing I was concerned about, and 1984mini25 alluded to it, was using a bolt that was too long. At the very least I would have cut off some excess threads to make it the same length as an original. I also note the comments about brittle plastic for the dizzy caps. If I go down the hole enlarging route, I will be careful!

[1984mini25]

Having just looked through my varied ebay purchase history, the length of the bolts is 18mm (thread length) in either m5 (standard) or m6.