Author Topic: Hard starting...timing issue?  (Read 3202 times)

0 Members and 1 Guest are viewing this topic.

Offline 4129R

  • Super Member
  • *******
  • Joined: May 2014
  • Location: Norfolk, United Kingdom, not far from Hethel the home of Lotus.
  • Posts: 2,734
Re: Hard starting...timing issue?
« Reply #15 on: Monday,March 25, 2024, 02:20:44 PM »
My guess 2 port = Zenith Stromberg head, 4 port = Weber/Dellorto head.

Offline SilverBeast

  • Hero Member
  • *****
  • Joined: Aug 2019
  • Location: Yeadon,West Yorkshire,UK
  • Posts: 709
  • 1974 Twin Cam Special
Re: Hard starting...timing issue?
« Reply #16 on: Monday,March 25, 2024, 02:55:21 PM »
I believe he probably means 2 port Federal Stromberg head had two carbs so shared a "throat" between the carb and the head.

Rest Of World Dellorto heads had two twin choke carburetters and a throat between each carb and just one cylinder - no sharing.

Offline jbcollier

  • Super Member
  • *******
  • Joined: Nov 2013
  • Location: Edmonton, Alberta, Canada
  • Posts: 5,962
Re: Hard starting...timing issue?
« Reply #17 on: Monday,March 25, 2024, 06:56:48 PM »
Heads that take Webers or Dellortos have four intake ports.  Heads that take Strombergs have two intake ports.

Offline Fotog

  • Sr. Member
  • ****
  • Joined: Feb 2019
  • Location: Huntingdon Valley, Pennsylvania, USA
  • Posts: 357
  • 72 Twin Cam
Re: Hard starting...timing issue?
« Reply #18 on: Tuesday,March 26, 2024, 06:19:22 AM »
Thanks, gentlemen!

Offline Bryan Boyle

  • Super Member
  • *******
  • Joined: Feb 2022
  • Location: Morrisville PA
  • Posts: 794
  • 1974 Europa JPS #142 3291R
    • Lotus Europa Collection
Re: Hard starting...timing issue?
« Reply #19 on: Wednesday,March 27, 2024, 08:52:58 AM »
Going to reclock (and move the wires one pip to the right) the dizzy to give me more adjustment range; right now, the wire pips on the cap are up against the bottom of the inlet.  At idle I'm seeing 16-17 degrees advance...can't move anti-clockwise any further.  Both mentioned that would possibly account for the hard starting I've been witnessing lately.  Also going to throw in a fresh set of sparkers.  Can't hurt.   

Talked to a couple wrenches I have been dealing with since the 80s and work exclusively on Lotus...with the pertronix, they usually set for 12 degrees at idle.  Wish me luck...will report back...;)
Bryan Boyle
Morrisville PA
Commercial Pilot/CFII/FAA Safety Team
Amateur Extra Class Operator & FCC Volunteer Examiner
Currently working on 3291R, ex 444R, 693R, 65/2163, 004R, 65/2678
http://www.lotuseuropa.us for mirror of lotus-europa.com manual site.

Offline Bryan Boyle

  • Super Member
  • *******
  • Joined: Feb 2022
  • Location: Morrisville PA
  • Posts: 794
  • 1974 Europa JPS #142 3291R
    • Lotus Europa Collection
Re: Hard starting...timing issue?
« Reply #20 on: Wednesday,March 27, 2024, 11:29:19 AM »
Well...reclocked the dizzy (and moved all the wires by one place anti-clockwise...but...discovered the below inside the cap.)

Darn.

Reason for reclocking is to move the spring cap snaps away from the bottom of the intake.  This is the second time that the cap has been machined by the rotor...my fault in installation, I'm thinking.  Mea culpa.

New cap and rotor on its way.  But still going to keep it reclocked: took all plugs out.  Screwed in compression gauge  in #1, tranny in 4th...moved car manually till gauge registered compression on 1.  Moved till read 10 degrees on flywheel.  Chocked, checked where rotor was.  Paint mark on dizzy body.  Close to where I moved the #1 wire.  lightly clamped.  Will install new cap when it comes in.

Bryan Boyle
Morrisville PA
Commercial Pilot/CFII/FAA Safety Team
Amateur Extra Class Operator & FCC Volunteer Examiner
Currently working on 3291R, ex 444R, 693R, 65/2163, 004R, 65/2678
http://www.lotuseuropa.us for mirror of lotus-europa.com manual site.

Offline BDA

  • Super Member
  • *******
  • Joined: Jul 2012
  • Location: North Carolina
  • Posts: 9,980
Re: Hard starting...timing issue?
« Reply #21 on: Wednesday,March 27, 2024, 11:36:49 AM »
Bummer! That's not close to the dumbest mistake I've made!

Offline Bryan Boyle

  • Super Member
  • *******
  • Joined: Feb 2022
  • Location: Morrisville PA
  • Posts: 794
  • 1974 Europa JPS #142 3291R
    • Lotus Europa Collection
Re: Hard starting...timing issue?
« Reply #22 on: Wednesday,March 27, 2024, 12:08:59 PM »
Bummer! That's not close to the dumbest mistake I've made!

I could write a book detailing all of the bonehead mistakes and it wouldn't be finished yet.  New cap and rotor on its way.  Old one looks ok. 

I'm not entirely happy with the 'sturdiness' of the clips holding the cap on.  Thinking if I get it to a point where the cap clips are in the 'clear', there won't be any reason for vibration or such to dislodge them and offset the cap on the dizzy body.  Of course, I could always throw a long ty-wrap around the body to hold the clips in place.  I think some mfrs had the right idea of using screws to keep the cap solidly on the body.  But, we have to work with what we have available, right?
Bryan Boyle
Morrisville PA
Commercial Pilot/CFII/FAA Safety Team
Amateur Extra Class Operator & FCC Volunteer Examiner
Currently working on 3291R, ex 444R, 693R, 65/2163, 004R, 65/2678
http://www.lotuseuropa.us for mirror of lotus-europa.com manual site.

Offline 4129R

  • Super Member
  • *******
  • Joined: May 2014
  • Location: Norfolk, United Kingdom, not far from Hethel the home of Lotus.
  • Posts: 2,734
Re: Hard starting...timing issue?
« Reply #23 on: Wednesday,March 27, 2024, 12:59:55 PM »
When the rotor arm rotates, does it describe a true circle, or an oval?

Is the distributor itself rotating properly, or is the cam that triggers the spark eccentric?

Offline BDA

  • Super Member
  • *******
  • Joined: Jul 2012
  • Location: North Carolina
  • Posts: 9,980
Re: Hard starting...timing issue?
« Reply #24 on: Wednesday,March 27, 2024, 01:08:11 PM »
I'm pretty confident my bonehead book would be thicker but let's not make this into a competition!  :D
Is the Pertronix dizzy taller or fatter than the Lucas one? I know it's tight under the carbs but I'm surprised it's that tight!

Be thankful you don't have a screw down dizzy cap or you'd have to take the dizzy out to take the cap off!! If you do use a ty wrap to hold the clips in place, I might wrap the ty wrap around the tabs of the clips rather the center since squeezing the clips would tend to loosen the tension holding the cap.

Offline Bryan Boyle

  • Super Member
  • *******
  • Joined: Feb 2022
  • Location: Morrisville PA
  • Posts: 794
  • 1974 Europa JPS #142 3291R
    • Lotus Europa Collection
Re: Hard starting...timing issue?
« Reply #25 on: Thursday,March 28, 2024, 04:01:47 AM »
When the rotor arm rotates, does it describe a true circle, or an oval?

The spring clips that hold the cap down are not the most robust (as compared to the original 25D dizzy clips and Lucas cap) and the cap can be easily displaced which means when it is, the cap itself is off-centered just a bit and the rotor carves the contacts (proof is the 2 that are machined by the rotor; the opposite ones show signs of arcing from the increased clearance between the rotor and the cap.)

Quote

Is the distributor itself rotating properly, or is the cam that triggers the spark eccentric?

The issue lies within the design/material used for the spring clamps.  It's an electronic dizzy, so there is no cam, only moving part is the rotor (and advance weights).  This is the second time this has happened, so...thinking of ways of modifying/adjusting the clips to make them hold the cap on more securely.
Bryan Boyle
Morrisville PA
Commercial Pilot/CFII/FAA Safety Team
Amateur Extra Class Operator & FCC Volunteer Examiner
Currently working on 3291R, ex 444R, 693R, 65/2163, 004R, 65/2678
http://www.lotuseuropa.us for mirror of lotus-europa.com manual site.

Offline Bryan Boyle

  • Super Member
  • *******
  • Joined: Feb 2022
  • Location: Morrisville PA
  • Posts: 794
  • 1974 Europa JPS #142 3291R
    • Lotus Europa Collection
Re: Hard starting...timing issue?
« Reply #26 on: Thursday,March 28, 2024, 04:08:22 AM »
I'm pretty confident my bonehead book would be thicker but let's not make this into a competition!  :D
Is the Pertronix dizzy taller or fatter than the Lucas one? I know it's tight under the carbs but I'm surprised it's that tight!

Be thankful you don't have a screw down dizzy cap or you'd have to take the dizzy out to take the cap off!! If you do use a ty wrap to hold the clips in place, I might wrap the ty wrap around the tabs of the clips rather the center since squeezing the clips would tend to loosen the tension holding the cap.

Pretty much same measurements, not too worried about that.  It is a bit tight in there...I pulled my old dizzy (the original Lucas one) out and stripped it down last night...to clean it up maybe?  They do make a P-tronix kit for it...nah...Not going to let this defeat me...I've come up against some of the best bodges Lotus designed into the Europa...not going down in flames over a distributor...lol

As for the ty-wrap...exactly where I thought it should go.  I'm going to try slightly increasing the arc of the clips and the amount of "bite" on the end where it holds down the cap to see if I can get some added 'clamping' pressure before resorting to a (d)po fix of a ty-wrap...;) 
Bryan Boyle
Morrisville PA
Commercial Pilot/CFII/FAA Safety Team
Amateur Extra Class Operator & FCC Volunteer Examiner
Currently working on 3291R, ex 444R, 693R, 65/2163, 004R, 65/2678
http://www.lotuseuropa.us for mirror of lotus-europa.com manual site.

Offline GavinT

  • Super Member
  • *******
  • Joined: Oct 2016
  • Location: Queensland, Oz
  • Posts: 1,224
Re: Hard starting...timing issue?
« Reply #27 on: Thursday,March 28, 2024, 08:58:25 AM »

I'm pretty confident my bonehead book would be thicker but let's not make this into a competition!  :D


Agreed, no competitions.
A new thread then?  ;D