1800 - right hand side running rich

Samblers Officially Full-On Dubber

236 posts · joined Apr 2005 · 19 Apr 2006, 11:23 am

#477755

Right, see my other post regarding my sick 1800 engine, currently in pieces whilst were camped in the garage yard!

Whilst its apart i've found that the Right hand cyl head is considerably more coked up than the left... what are the causes of rich running?

My Right choke is a little sticky but always comes off (I think... have checked this numerous times), and i've taken out both main jets (behind the 13mm plug?), which are marked X132.5 and dont look like they've been drilled.

Is there anything else i can check?

thanks, Sam

kombidaze Slammed & Awesome Dubber

83 posts · joined Aug 2003 · 19 Apr 2006, 6:27 pm

#477951

:cry there are lots of little things that can all add up to rich running. both carbys and valve adjustment can be the cause, is the head ok? the carbys are an art and a science to get right, best thing is to locate a good workshop manual that explains it in detail, there are a couple of haynes manuals for sale in parts for sale. Search this forum for carby adjustment for some leads
the main idiosncracy with these twin carbies is that they are not the same both sides the left has more adjustments than the right. its probably the idle mixture screws located on the outside of each carby and or the accelerator pump adjustment or the throttle bushes are worn, or there were vacuum leaks from perished rubber connectors or they were out of sync or the float levels are out. try this site http://www.ratwell.com/technical/DualCarbs.html

Samblers Officially Full-On Dubber

236 posts · joined Apr 2005 · 20 Apr 2006, 10:39 am

#478201

hmmm... wouldn't air leaks and such tend to make the mixture LEAN though? I know my throttle shaft on the RHS is a little worn but this would suck in more air, not fuel???

Also, I dont know if i'm right in thinking that the idle adjustment isn't really that much of a big deal cos it has nothing to do with the mixture when NOT idling, i.e., when driving normally - thats where i think the rich running occurs.

Surely the amount of fuel is determined by the main jet?

I know i may need to get them balanced.

Andy Andy\'s Adventures

2,820 posts · joined Nov 2002 · 20 Apr 2006, 4:17 pm

#478322

Main jet is the main source of fuel when driving as you mention, things that also affect it will be air correction jet and float level. I'd have to look at the book to confirm what they should be.
Other than carbs, you need to look at general state of tune also, including ignition/timing/advance etc.

Are you sure it's one side running rich and one OK, or is it really one OK and one lean side? Generally the heads will have an amount of black deposit when running fine.

I feel for you, we had to camp out in a mechanics when we blew a head gasket crossing the Nullabour, thankfully we made it to Perth before repairing. Make sure it's repaired right and you can get back to enjoying the trip!

👍

Samblers Officially Full-On Dubber

236 posts · joined Apr 2005 · 22 Apr 2006, 10:01 am

#478954

Cheers for your comments 😉

It seems like tuning the twin carb set-up is a bit of a dark art so I'll see how i go now its all been rebuilt and put back together... at least its not going knock-knock-knock now!

I have a feeling that the carbs were poorly tuned/balanced previous to the rebuild

S

Andy Andy\'s Adventures

2,820 posts · joined Nov 2002 · 24 Apr 2006, 3:52 pm

#479755

Cool,
Kombi twin carbs no dark majic, just a little different to "normal". As long as you either follow the manual (or the atwell sight) you should get pretty close.
I was a little firghtened by them initially (coming from a single carb beetle), but did not take much to figure them.

So what went on the motor requiring a re-build?

So where abouts are you, where you heading, and how long on the road??
Hope your mobile again anyway!
👍

Samblers Officially Full-On Dubber

236 posts · joined Apr 2005 · 27 Apr 2006, 10:56 am

#481014

Just done 1000km's and it seems OK - slightly better economy too so fingers crossed!

We're in QLD but have driven over from Perth (13,000km so far!) on a lap of honour round the island.... man, its a big place! We're going anticlockwise so heading north now following the weather, but have to be back in WA by July to start jobs and such, tsch!

Our troubles started somewhere in SA where the engine developed a bit of an unusual noise... a VW guy told us our camshaft was rooted but fearing the $4K rebuild we moved on gingerly!

By the time we go to Brisvegas we could ignore the knocking noise no longer, bit the financial bullet and split the crankcase before it shat ityself on us (probably somewhere in the boonies, which is where we're headed next). Turns out it wasnt the camshaft rooted (predicited by 3 different mechanics), but it was the gear on the crankshaft that drives the camshaft come loose, as well as a loose dissy drive gear. Apparently this is quite unusual.

Anyway, we have a new (old, inspected tested) crankshaft and did the bearings etc whilst we were in the guts of the thing. Spent 4 nights camped in the yard of the garage and the missus spent most of it at the pool or the beach so it wasnt all bad!

Lets hope it holds out across the top... its a bloody long way to get towed back to perth!