Carborator rebuild questions

[radmanrugg]

Hello,

Could use some advise on carburetor troubles.

1. One carb (front) is missing a plug in the top section. I don't see a part number or anything on swiss army or manuals. Its right next to where the accelerator pump lever goes in. (FYI it looks like a freeze plug). Dirty air can enter. I am hoping there is a solution other than getting a new carb top. I thought of a rubber cork but not sure it will stay in place.

2. Having some issue with carbs. I measure 1.5cm roughly between top of middle and top carborator parts down to fuel level. I measured before taking anything appart on both and its pretty much the same. Problems started before rebuild where its running very rich and no power off idle. I am guessing fuel level issue. But I would think 1 carb would be off not both on my initial measurement before rebuild.

3. Back carb sucks a whole bunch more air; over x2. Even with idle screws turned in. The choke plate seems identical and orientation verified. I guess I should swap them to see if problem follows the choke plate.

I have rebuilt and thoroughly cleaned both and used all new carb rebuild parts. At least fuel weap issues are addressed now.

Looking for ideas. I have yet to find a good description of what points to measure from on fuel float level. Pictures would be a thousand words on where to measure from and how far down.

Many thanks for the DIY post on making the tool to measure with.
viewtopic.php?f=9&t=6054

[edzz]

From page 121 of repair manual “level measured from the joint face of the carburetor at test pressure of 1.8 meter water column” “16.6 +- 1mm”

And

Thank Jim L for his great page http://www.goatwerks.com/carbarticle.htm
http://www.goatwerks.com/carb.htm

[radmanrugg]

Thanks Jim for the tidbit. I will have to use another washer on float needle valve.

Update:
I swapped the choke plate mechanisms and now both carbs suck way too much air. Even with idle screws all the way to full spring compression. There was lots of whistling noise and air racket. By putting my finger in strategic places around the choke mechanisms, I could alleviate a noise here or there. Also the choke plates themselves got really cold. (effect of air going to a lesser pressure). When taking them off I noticed they were wet with gas also. I also think the gaskets are quite thin.

So my question is would a tube of gasket maker be alright on these? Silicon or something? I don't know if gas will eat them. Or try double gaskets (an expensive order for that).

Update again:
OK did some online research. Gas (petrol) and silicon make a very bad combination. There are some very expensive ones that are petroleum resistant.

One guy recommended this "PLS® 2 Premium Thread & Gasket Sealer" which is made for petroleum use on threads and gaskets.

Another suggestion was to take the paper gaskets and put them in water. This makes them pliable and form fitting. Anyone have experience with this?

Regards
Scott Ruggles

[pcolette]

The chokes on the Pinz carbs are different then most. These chokes do not reduce the airflow thru the carb (like most carbs) but instead add fuel to the mixture. The plates I think you are referring to are the throttle plates. The choke is actually referred to as a starter valve and is mounted to one side of the carb. It is item #44 on the diagram:

01-40.jpg (183.31 KiB) Viewed 6939 times

The choke plates (#37) would be wet with gas because gas flows thru the starter valve before being added to the fuel/air mixture.

Hope this helps.

[michaelh712]

I also had some major carb problems years ago and traced the problem to a missing plug on one of the carbs. I punched a small plug from an aluminum sheet and affixed it to the carb with JB weld. Problem solved and no more problems.

[edzz]

If you get feed up messing with them many have shipped their carbs to Jim L for rebuild and been pleased with the results.
http://www.goatwerks.com/contact_us.htm

[dadnova]

Check the flatness of the plates to make sure a good tight seal is being made, mine were not, therefore over fuel, really noticed it from an idol, my Pinz did the same thing, all it was were the surfaces of the carb were warped, I just sanded them on a flat surface and wa-la, problem fixed.

You have to love all the puzzles the Pinz gives.

[radmanrugg]

Thanks for everyones advise.

I finally broke down and picked up a refurbished carb to fix the excessive idle air intake issue. Now both carbs match air intake at idle . I was then quickly able to get them to match with some throttle added as well. Used my left over carb upper to replace the missing plug hole. Also took the emulsion tube supports out of one that were a bit damaged when a protective strain bit came loose and was bouncing around on the emulsion tube supports.

I used a flat granite block I have for sharpening and some 600 grit sand paper and i was able to get the choke (idle starter circuit) covers flat and solved my seal problem there.

I was able to set the float levels with the brake bleeder nipple DIY mod. Thanks again for that. Saved me a bunch of money. It seems to work at steep angles and is not overly rich or lean.

Running good again.
Regards
Scott Ruggles

[ako]

In the process of cleaning out my rear carb now. Posting this here are most of the experts are already in the thread.

Funny thing was the front carb was missing part number 8 above, which is listed as "Protect Straine" on SAV website.

When I was cleaning out the rear carb I found the missing item. Luckily it got stuck on the emulsion tubes and didn't pass by the butterfly.

I now have two questions.

The first is it seems the starter body on my two carbs were set up differently, need to know which way is correct.

Is there a diagram which shows the correct clocking of the item 37 against the item 41. Obviously there are only 4 answers and only one of those is correct.

See how it is now on the rear carb :



I haven't see anywhere a diagram for this, including Jim's Goatwerks write up. My front carb had the larger trapezoidal slot at the top, rather than the kidney bean.

The second is, the inner tubes on the emulsion support are bent up.

This view shows how much they have been forced over :



I don't know how they have been damaged so badly, you can see the worst of it where the horizontal injection tubes are located (item 32).

Is it going to be ok just to straighten these out, or they definitely need replacing? Could it have been the strainer bouncing around to do this damage?

As always, any help would be appreciated.