HS35 carb-whats missing here????

markus · 08-21-2008, 05:35 PM

Think I found at least one problem as to why the Rupp would not run. I would guess that its just a service plug thats missing, but I have nothing to compare it to so I'll ask before I make a plug and seal it up!

Sorry, my camera will not do close ups

just above and to the left of the low speed needle, there are three (maybe 4) passageways exposed. should it just be a plug or is there something else that fits there? It s lauson carb off a 1970 tec hs35 on a Rupp scrambler

ryan68bug · 08-21-2008, 06:17 PM

I fought a carb for a long time before I gave up and just bought a brand new one from RuppParts.com. That did the trick! For whatever reason, my carb simply could not be suitably cleaned, and I can only imagine what was stuck inside those passages...

mcanders · 08-21-2008, 08:50 PM

You are missing a welch plug. They come in the $10 rebuild kits, there are two, the other is inside the bowl area. Just clean the carb really good, you are already halfway done with the welch plug missing, and reinstall new plugs.

markus · 08-21-2008, 09:51 PM

Quote:

Originally Posted by mcanders

You are missing a welch plug. They come in the $10 rebuild kits, there are two, the other is inside the bowl area. Just clean the carb really good, you are already halfway done with the welch plug missing, and reinstall new plugs.

I figured (ok actually hoped) that was the case! Thanks for the reply!

**GTO** · 08-22-2008, 04:13 AM

To install you have to tap them in without making a flat spot in the middle, try using a small pipe or socket that is just inside the diameter. A little lock tite on the ring will help seal but not absolutely needed.

To remove the plugs you use a small drill or sharp punch without hitting the inside/carb then pry off.

ATKRIDER · 08-22-2008, 09:50 AM

Quote:

Originally Posted by GTO

To install you have to tap them in without making a flat spot in the middle, try using a small pipe or socket that is just inside the diameter. A little lock tite on the ring will help seal but not absolutely needed.

To remove the plugs you use a small drill or sharp punch without hitting the inside/carb then pry off.

Not to conterdict you on the install but in my opinion you want to hit the plug so to dent it in the center. That way it actually expands the convex plug into the hole tightly. Those passages are actually the low speed circuit that were caused from manufacturing the carb. You do NOT want a vacuum leak there or idle quality will be effected. You might want to just install the plug in whatever way you are comfertable with then silicone or epoxy over it.

heavy d · 08-22-2008, 11:10 AM

another trick is to paint over the welch plug with clear nail polish once its installed,that way you wont have any vac leaks

**GTO** · 08-23-2008, 04:13 AM

The manual says not do dent the plug and you don't see them dented from the factory thogh some have rings. A socket or small pipe will expand the plug if you stay of the edges because they are wide enough ID. The lock tite seals the plug as per manual. I never had one leak or come off.

markus · 08-23-2008, 11:46 AM

alright, got it going, went ahead and bought a rebuild kit fir it yesterday and did the deed this morning.

She fired right up, no leaking fuel, but I gotta figure out the fine tuning. its very finicky. I may have put the linkage in the the wrong positions though. I did have to readjust the throttle cable after I installed the carb a bit but since This carb was half rebuilt I figured that the PO may have gotten things a bit screwy.

I can get it to idle decent but it will fall on its face when you hit the gas if you work it to keep it running and get it going it runs really good high end (bikes alot faster than I thought it would be

) and you can vary the throttle under load.

Of course I have not even looked at the plug or under the flywheel yet.

markus · 08-23-2008, 03:57 PM

Quote:

Originally Posted by markus

alright, got it going, went ahead and bought a rebuild kit fir it yesterday and did the deed this morning.

She fired right up, no leaking fuel, but I gotta figure out the fine tuning. its very finicky. I may have put the linkage in the the wrong positions though. I did have to readjust the throttle cable after I installed the carb a bit but since This carb was half rebuilt I figured that the PO may have gotten things a bit screwy.

I can get it to idle decent but it will fall on its face when you hit the gas if you work it to keep it running and get it going it runs really good high end (bikes alot faster than I thought it would be

) and you can vary the throttle under load.

Of course I have not even looked at the plug or under the flywheel yet.

Hello, my name is Markus and I am a MORON!!!!! Why was it so finicky?? Because Markus the MORON put the high and low speed needles in the wrong way

I just swapped them out (luckily I didn't crank down on them and damage the needles) She runs out smooth now

One of these days I gonna have to fire my mechanic