mtntopgeo

My Feedback: (12)

I've got a 4 or 5 yr old Norvel .074, which has accumulated a lot of flights, but still runs very strong. Recently, I noticed that theengine would "wander around" lean, right on, too lean, deadstick. Much to my suprise, found that the carb was extremely loose in the crankcase. The bolt was still in place, tight, but the carb had a lot of up/down movement. The holes through the base of the carb had elongated quite badly, so that now the carb can't be kept against the o-ring. Anybody else have this problem? And,If so, what was your cure? Bushings would be a pain to install, but doable. Lok-Tite, epoxy, RTV, ??? ............................ George K.

Andrew

George -

Get yourself some large diameter silicone fuel tubing and slice off O-rings from the end. You can cut whatever thickness you need to get a good seal. The tubing will compress and conform to the uneven carb and give an airtight seal. I usually replace the OEM O-rings with silicone since the rubber is hard and generally leaky.

andrew

eroc144

My Feedback: (1)

George,

A couple of my N74 carbs are loose but none of the screw holes have actually elongated - Yow.  If you don't normally remove the carb then perhaps use JB Weld to install it permanently.   Run some weld on the male part of the carb body and take care that nothing drips into the shaft area - I'd orient it upside down while the weld sets.  Afterwards run another bead around the carb/case joint.  Another option would be to use weld to completely fill the carb holes and then redrill them. 

EG

gkamysz

My Feedback: (19)

The new one I attempted to take apart last year had the carb glued in at the factory. Felt like epoxy. I never did pull the carb out.

mtntopgeo

My Feedback: (12)

Andrew,the "variable width" O-ring (using the large fuel line) appears to be the quickest, cleanest method of sealing up this carb. I'll try this first. This problem was a long time in the making. The engine was used, when I bought it, & I've run a lot of fuel through it over the last 4 years or so. Never touched anything on the engine during that time. Think that once the O-ring had taken a set, & allowed some movement, the vibrations took over, & started to "saw" a slot down the carb throat. I'll be watching for this problem more closely, in the future.


EG, I like the idea & your method ofusing JB Weld to permanently attach the carb to the crankcase. If theslots show signs of getting longer, I'll go thatroute. I'm a little timidabout filling the slots, & redrilling the throat. If that little sliver of JBWeld breaks off, then theengine will ingest it.


Greg, I've some earlier .061 Norvels with the glued / epoxiedcarb. My original thought was "how crude". Now, I'm thinking "that's a pretty good idea".


Guys, thanks for your inputs. ...................... George K.

machnone

My Feedback: (31)

 Another "quick" fix is to cut a 1/8" or longer section of surgical tubing that has an ID about the size of the carb barrel. The length is not super critical as you want to compress it when you rebolt the carb.

 I had the same problem and tried 2 o-rings but that did not work. Even with the surgical tubing the carb still "floats" a little but does not leak air and will hold a needle and throttles just fine. 

combatpigg

My Feedback: (3)

I would just clean everything up good and JB WELD it in there. End of ball game.