Tale of woe - first 3 weeks in a Marlin

[gavin]

Well,

I passed my driving test on Oct 2nd and my wee Roadster was already waiting for me. Since then in 3 weeks I've done just over 2,000 miles and the following catalogue of woe has unfolded...

Backbox became 2 smaller, less effective backboxes i.e. it split in half. Was replaced with a 106 backbox and some cunning welding.

Then...

Speedo cable came loose and fouled clutch mechanism - people thought I had a turbo and dump valve set up coz every gear change went "kkk--shhhhh" heheheheh. Was re-routed and clamped in place.

Then...

Intermittent wiped failure - new wiper motor required methinks.

Then...

New backbox mounting worked loose, resulting in a sheared manifold. Manifold puttied up, bit of flexipipe dropped in to take the stress off and it's running ok.

The upshot of this is that my wee car is going down to Elgin for a visit to Custom Craft where it will receive a full custom system from manifold to backbox in shiny stainless steel at a cost of ?450. Ouch, but hopefully worth it long term. Then for Xmas she is getting twin 1.5 inch carbs from a rallying mini.

Does anyone else here have a custom system? What kind of backbox etc did you opt for?

Cheers,

Gav.

[b_caswell]

Re: Tale of woe - first 3 weeks in a Marlin

Hi Gav, You have probably doubled the annual mileage of half the roadster owners already. Most roadsters use a short system that runs under the wing and out infront of the rear wheel. This keeps it simple and probably cheaper. Make sure you get the correct needles and springs for your engine and cam set up or you will be buying shares in BP.

[gavin]

Re: Tale of woe - first 3 weeks in a Marlin

Hiya Ben,

Put a another 240 miles on it with the putty manifold still in place - eeek! Nervous driving I tell ya. My system is indeed the short, straight out the side type. Do you know anywhere i can see a list of carb needles / springs for the twin carbs for different engine / cam set ups? Also, is it merely a matter of matching engine number or similar with relevant ref numbers for needles or is there more to it than that?

Thanks as ever guys,

G

[lizbillings]

Re: Tale of woe - first 3 weeks in a Marlin

Hi Gavin. You may be better to put a new question on the forum about needles/springs etc.

[kdn17]

Re: Tale of woe - first 3 weeks in a Marlin

I might be opening a whole bag of worms here but a long time ago I gave up continually trying to keep twin carbs balanced and stuck a single bigger carb on a flowed inlet manifold. (Not on my Roadsterby the way) It was sooo much easier to keep balanced!!!!

[neilryland]

Re: Tale of woe - first 3 weeks in a Marlin

Another option is Fuel Injection, I did my own conversion about 15 years, or more, ago.

[lil_red_roadster]

Re: Tale of woe - first 3 weeks in a Marlin

Having tried twins on the B series I gave up after a couple of weeks and put the bog-standard single back on. Sacrificing a few BHP for reliability and convenience works for me...

However, inspired by Neil and others, and conscious of being in the 21st century, I am planning to fuel inject the B series. A single 48mm throttle body with integral injectors and fuel rail (ex Honda Firestorm), some additional plumbing and a Megasquirt ECU are "all" that's required. If that works OK (and it's been done successfully by others) Megasquirt can also be used to trigger the ignition...