18RG 40mm Solex PHH - mixture screws not sealing all the way in.

[JadeEstevez]

Basically, on one of the solex's on my 18RG, if you screw the mixture screws all the way in the engine won't stop idling, Do it to the other one and it will. Is there a way to make them seal better or should I purchase some new screws? Where can I get some new screws that aren't $50 each (Ebay >___>)?

Do I even need them, Am I over reacting?
I'm looking into it because I'm going to be buying rebuild kits for the carbs and I'm unsure if it is a big problem or not a big deal at all...

Thank you.

[BrianGT]

Not being funny but it could be as simple as the carbs not exactly balanced so that one is running harder than the other......shutting the weak one down wouldn't have as much effect as shutting down the other....

Assuming they are nicely balanced I would remove the idle screws and check very carefully for ribbing on the taper and to see if they are bent.
I had a similar problem and an airline down the hole cured it....I had one barrel that could be shut off without doing a great deal and blowing out the passages cured it.
Good luck!

[JadeEstevez]

Ahh cheers for that, I'll give it a go with our air compressor. If they are bent or there is ribbing, Should I purchase new ones or is there a way to fix them? Not sure if they are balanced correctly but I'll get that done when I rebuild them as I may need to dyno the thing due to the HKS cams.

Thanks for the help mate!

[George]

It really depends on whether someone else have already touched it. I once came across a carb with drilled throttle plate...its previous owner seemed to had wanted MOOORE IDLE RPM at all costs.

I'd also check for air leaks, first time (safer) with wd40, then if nothining is found repeat with plenty of water

[JadeEstevez]

Alright, I'll suss that out too. The only area I imagine it could possibly be leaking from would be where the carbies bolt to the manifold, I'm unsure of how tight to do the bolts there as I'm paranoid of breaking the carbies body, I've seen it done with solex's a lot...

[BrianGT]

Just make sure that they are tightened to the manifold evenly and firmly....I use O-ring plates for my Dellorto's but a one piece gskt is fine. If the gskt is good they will seal without too much hassle......as has been mentioned a spray of WD40 will show leaks.

I actually believe it's the balancing of the carbs that's at fault. If one carb is running harder the butterfly will be open and mixture will get through to the engine regardless of idle adjustment screw positioning. When the butterfly is open slightly it allows air to flow over the progression holes in the body and sucks mixture in to the engine.
It's not a bad idea to fit the carbs to the manifold first and then to the engine. That way you can see if both butterflies are opening together whilst looking down the barrels...and also if both are fully closed.

When you do set the engine up make sure your ignition timing etc. is set first...carbs should be done after the ignition side is deemed to be ok! Obviously you may have to twiddle with the balancing screws to get it to run but setting up mixture and balance is the last link in the tuning chain.
it's not hard to do.....you just have to listen to the engine and adjust one thing at a time and listen to how it affects the engine speed etc...
Good luck mate!

[JadeEstevez]

Yeah timings all good, Electronic ignition rocks I tried O-ring plates in a soft mount kit I had but there isn't enough thread to work with on the manifold... I'll have to get longer threaded studs for it.

I'll set up the carbs when I rebuild them, I'll remove them with the manifold. Ordered the rebuild kits yesterday

Thanks for the help everyone.

['ol_skool_'75]

Ahh bugger man If Robin was free this weekend I'd suggest going to see him. We had a look at the carbs that came with the RG from you...... Besides having to make a new gasket they were perfect ( Now I feel bad cos it sounds like I'm rubbing it in )

Cheers

Bear

[JadeEstevez]

Nah it's all good. I didn't wanna keep the carbies off of that engine, It was an unknown condition... Just luck that they are mint then I should have had a better look, Hehe.

[BrianGT]

Nah it's all good. I didn't wanna keep the carbies off of that engine, It was an unknown condition... Just luck that they are mint then I should have had a better look, Hehe.

Don't worry mate.........you can sort yours!

It isn't hard work or relatively expensive...just a bit of time and patience and they will be running like a dream!
You can "almost" set them up off the car..once they are on the manifold you can almost balance them and set the throttle arms by eye........then it's just a matter of fine tuning.
Stripping them and cleaning them out costs very little........you can usually use the old gaskets.
Good luck mate!

[JadeEstevez]

Cheers. I'll update when I get the rebuild kits and have a chance to take my car off the road for a day.

[Willofan]

try this from River, it might help when you put your carbs back on

http://www.toymods.org.au/forums/tec...rocedures.html

[JadeEstevez]

Thanks mate I've save that link.