700S Carb and intake issues

[Willie]

In anticipation of rebuilding the carbs on my 700S in the very near future, I thought I'd get my ducks in a row and ask a few questions.
1st involves the rubber o-rings that seal the intake manifolds to the head. Has anyone ever inspected their's while they had access to them? I ask because, on the Suzuki GS models, it's very common for the o-rings to harden and deteriorate. I've replaced them on several of the GS's I've had over the years. Fwiw, my plan is to inspect them while I have the carbs off. I'm fortunate to have a vendor nearby that sells o-rings.
2nd concern involves the rubber diaphragms. I've read all the other threads on the topic and have had to replace them on a 650 Hawk GT I owned a few years ago. Back then, I have no idea how I found him, but there was a guy who made replacement diaphragms as a side gig. They were relatively inexpensive and worked like a charm. Having looked on eBay, I'm surprised at all the replacement diaphragms available. The prices range from $18 to the mid 30's. Unfortunately, they're all made in China. Has anyone had any luck with these?
To be contd.

[Bob H]

According to Partzilla and visual inspection, the 700s has same carbs as the late model 91-2003 NH 750.
My gasket set from Partzilla said 700s on the zip lock bag, they fit my 93 NH 750 perfectly.

I had no reason to remove intake manifolds (rubber) from the head. I did use some silicone lube friendly to rubber to facilitate putting the carbs back in the old hardened rubber intakes. (Syl-Glyd, OK for brake cylinder rubber seals etc).

2nd concern involves the rubber diaphragms. I've read all the other threads on the topic and have had to replace them on a 650 Hawk GT I owned a few years ago. Back then, I have no idea how I found him, but there was a guy who made replacement diaphragms as a side gig. They were relatively inexpensive and worked like a charm. Having looked on eBay, I'm surprised at all the replacement diaphragms available. The prices range from $18 to the mid 30's. Unfortunately, they're all made in China. Has anyone had any luck with these?

I paid out the nose for OEM Honda diaphragms because they were available, I plan on keeping the bike, and I wasted at least an entire day looking at youtube videos, various searches and threads from other motorcycle models regarding the aftermarket diaphrams.

I saw a lot of mixed reviews and very little long term information. I also heard of someone in USA doing it on the side, that went out of business, then the Chinese took over.

I felt very mixed emotions spending that much money - but the time and effort I already had into pulling the carbs (again after 10 years) cleaning and replacing all other replaceable parts (jets, gaskets, fuel lines, etc) I just didn't want to gamble on diaphragms.

Also I did not have experience with failed diaphragms before, did not consider myself an expert - but saw small slits and just took the plunge.

[Hend238]

Maybe this shop in the UK could be a good option?

https://nrp-carbs.co.uk/shop/index.php?route=product/product&product_id=766

[Pete in PA]

While apart I'd inspect/replace the rubber between the carbs and Head.  You dont want a vac. leak there. You'll never get the jetting/running right.

My slides were fine, no experience with the China ones.  The OEM ones are salty.

If I were to try the China ones I'd replace all 4.

[Willie]

Another fuel related item I forgot to mention was the petcock. I was surprised to discover that the lever assembly is riveted together. What BS! I wanted/need to replace the o-ring in there. I'll be looking for a replacement assembly but will be considering drilling out the rivets and tapping threads for small screws. I know I can get the necessary o-ring.

[Hend238]

Another fuel related item I forgot to mention was the petcock. I was surprised to discover that the lever assembly is riveted together. What BS! I wanted/need to replace the o-ring in there. I'll be looking for a replacement assembly but will be considering drilling out the rivets and tapping threads for small screws. I know I can get the necessary o-ring.

This is the kit you want. From the same place in the UK. https://nrp-carbs.co.uk/shop/index.php?route=product/product&product_id=4470

I used a mill to remove the rivet heads and drill the stems prior to tapping. There are very good instructions that come with the kit.

[mollusc]

All Balls make a good kit for the 700S.  No need to go to the UK and pay shipping.  I had to import one from the Netherlands before the AB kit existed and it was very pricey.

[Hend238]

Even better.

[Bob H]

Another fuel related item I forgot to mention was the petcock. I was surprised to discover that the lever assembly is riveted together. What BS! I wanted/need to replace the o-ring in there.

My experience may be useless for your situation - but I had a leak from petcock area earlier this year. At a casual glance I couldn't tell where it was leaking from, but it was not a hose.

The OEM petcock cost a fortune, and Amazon had very solid reviews for an aftermarket one for my 93 NH 750, which I ordered.

When I removed the old petcock, I discovered that "my leak" was at the O-ring that connected the petcock to the gas tank. It was flattened out and hardened. The new petcock came with that O-ring, it fit perfectly and was pliable. No more leak.

The Amazon products made in China come and go, with different "brand" names. The one I ordered is "no longer available" but lot's of other ones have taken it's place. My aftermarket petcock is working great so far.

[mollusc]

There really aren't any aftermarket options for the 700S petcock.
There are two separate "sides" to the thing, each of which has a different rebuild kit.  The vacuum diaphragm is pretty readily available, but the x-ring inside the riveted section requires one of the more obscure kits.

[Willie]

It's an X-ring?!  Bummer! Every GS and GT petcock I've opened up were standard o-rings.

[mollusc]

Yeah.  That's part of the reason why no replacements were available for a long time.  Nothing standard will really work.

[capt42104]

Willie,

I did replace the O-rings between the boots and the head as a precaution and previous history. The boots are really in good condition. I was able to source the O-rings from RockymountainATV. The old ones were really hard by the way.