Carb Diaphram Replacement

[SilvrT]

Does anyone have a link to a post (anywhere) that details the process of replacing/repairing the diaphrams (with pics) on a 1st gen?

[Gearhead]

I dunno, but the service manual (available on this site) shows how to get them out, and they're REALLY easy to access on the bike, which is amazing (I guess SOMETHING has to be easy to access!)

 

Remove side covers and lower fairings, and the caps are staring out at you. Four screws each and you're in, but there could be a little trouble here. For one, there is a tamper resistant torx screw for which you can buy a special wrench OR us a combination of small vice grips and a standard torx wrench to get it out. Second, these screws are often stuck in there pretty good. I used an impact driver when I pulled one cap to inspect, but tapped VERY GENTLY on the pot-metal carb bodies. The other day I picked up (16) 5mm x 12mm hex head bolts to put in in their place when I replace the diaphragms this weekend. Stainless socket head or button head looks really cool, but you can't see them anyway with the fairing on so I went cheap, zinc-plated hex head. I will install with a touch of anti-sieze - esp. important if you use stainless.

 

Once the caps are off, the slides pull right out. Inspect parts for wear and dirt, etc. You can remove the pilot air jet #2 if you like - I will probably spray some cleaner in the accessible orifices. Remove the needle from the old slide, put into new slide, reinstall. Check the condition of the tiny o-ring at the bottom - probably needs replacing. Also, keep everything VERY clean.

 

That's about it. Look at the manual for pics.

 

Jeremy

[SilvrT]

Thanks Jeremy... and I'm sure the info will be helpful to others too!

 

Having read several posts, I had a feeling it would be quite simple. Your explanation is very clear and consice...are you an instructor of some sort?

[Gearhead]

You're welcome. Instructor? Nope - mechanical design engineer, so I have to write instructions and assembly notes for my designs.

 

But it struck me that you're the same guy who just had his Venture up around 120mph or so, right? So you're not short on top-end power, which is where bad diaphragms are supposed to hit you. Just a thought.

 

Jeremy

[GigaWhiskey]

If a philips head or two gets stripped, you can dremel a slot in the head so you can get a flat head head screw driver in there.

 

NAPA had some bolts to replace them but they were pink. They should findable at a nut n bolt shop like Fastenal.

 

I had to use my air compessor to pop the idle screws out so I could get some cleaner in there and then blow it out later.

[SilvrT]

You're welcome. Instructor? Nope - mechanical design engineer, so I have to write instructions and assembly notes for my designs.

 

But it struck me that you're the same guy who just had his Venture up around 120mph or so, right? So you're not short on top-end power, which is where bad diaphragms are supposed to hit you. Just a thought.

 

Jeremy

 

That's correct! Actually, I wasn't thinking about doing anything in the immediate future. Sort of gathering technical stuff together for when I do which will probably be over the winter.

[83 decked out]

whats the best spot for getting the replacement diaframs? And should the needle move in and out a little in the diafram? I took mine apart cause I am still hearing some popping and not wanting to run ecept with the choke on. Any help? I think the next step I need to pull the carbs but shes running but have to feather the throttle to take off?

[CrazyHorse]

flatoutmotorcycles.com usually has the best prices for diaphrams

[Gearhead]

I thought about dremmel-ling a slot in the screw heads (some were very tight), but vice grips did the trick. Now they all have hex head bolts.

 

I bought mine at RonAyers.com; they were $55 each. They, Zanotti and FlatOut seem to be very competitive. usually Zanotti wins, but not in this case.

 

Yeah, the needle moves a little in the slide, but it's spring-loaded downward. If you push it into the slide it will go, maybe 1/16 of an inch, but it should spring right back out. Your problem sounds like it's not getting enough fuel. Have you cleaned the carbs, and I mean THOROUGHLY? How about fuel / float levels? Seafoam out the wazzu?

 

Jeremy

[CrazyHorse]

I had to dremmel most of mine it seems the head is the part that fuses to to the carbs and not the screws inside. When I dremmeled them the screw part usually popped right out. I would probably rebuild them with all 8 diaphrams 4 big a 4 small and make sure the tiny pilot jets in the jet block are clean mine werent so the bike wouldnt idle. I used a bristle from a steel brush to push out the gunk sea foam aint going to do it. Just peace of mind thing for me.