JBM Carb Boots

[billychop]

I also have the JBM boots and echo what Grizld1 said. Good part and great guy to deal with. I HAD to buy these boots since I got a grand total of 28 miles out of the set I got from Mikes, literally 28 miles. I have no idea how ethanol can have such a dramatic affect after only 28 miles but whatever. The JBM ones are at 415 miles and counting. Highly recommend them if you need a set.

[ShakerNorm]

Ethanol is actually pretty corrosive stuff - especially on rubber..... if you've used it - you may end up swapping out fuel lines too..... although I'm guessing most newer ones would probably be OK.

[billychop]

Oh I know it's pretty nasty stuff. But I can't imagine selling a product to a community I depend on to make living that could fail that fast. Instead of saying ethanol CAN ruin these boots, it should have said these may not last a week if you run ehtanol, in which case I would never have wasted my $40+ dollars on them to start with since you can't buy non-ethanol gas anywhere anymore.

[ShakerNorm]

That's why everyone here is getting JBM's boots........

Up here in Canada, Ethanol isn't everywhere, yet, but it's coming...... I'm still running the original boots on mine, but at least I know where to get GOOD replacements!

[jtc]

I can believe it. The stuff is nasty. I not only found out with carb boots but also so with a more expensive item and that was an Omars tracker tank. I sent the tank back to him a month ago after he said he would replace it and haven't heard a peep from him since and so far no tank. I guess I will have to get gas from a race fuel place here in town whenever I want to ride my tracker. Thats providing I ever see that new tank. Aint that damn handy.
jefft

[billychop]

You guys are misunderstanding me. I KNOW ethanol is nasty. What I don't get is continuing to sell them to a community you depend on for your business. If you are selling a product to a guy you KNOW can fail before he gets back home from his FIRST ride on the bike, then that seems like bad business to me. Actually it is the definition of bad business.

[grizld1]

Guys, here in Illinois 10% ethanol fuel has been around for over 30 years, and it's been hard to buy gas without 10% ethanol content for around 20 years. There are plenty of old high-mileage bikes with the original OEM rubber boots around here that have never been run on anything else, so don't get the idea that your OEM or Tour Max boots won't stand up to 10% ethanol--they will. Re. the old boots from Mike's, ethanol may have broken them down faster, but the rubber compound simply wasn't up to the job regardless of fuel, particularly if carbs were run unsupported with the air box removed.

The biggest problem you're likely to run into from first-time 10% ethanol use is a rapid dump of partially-dissolved varnish and crud from the fuel tank. Use in-line filters, and have some spares handy.

[preston]

I have run a set of Mikes boots, on my 77 since June or so,, i have about 2500 trouble free miles,,
BUT, from the get-go, my intuition said to use the old stock Yamaha metal shrouds around the new rubber boots. (yes, you grind them a little, at the barbs, which have vacuum ports,, which are plugged, which i have NEVER had any trouble with the plugs staying on, and no cracks, or air leaks, but you guys got me worried, so I have a spare set now)
Be sure to retighten the little hex head bolts on the shroud, after the motor has been hot.
NOW...
I have a 2 nd set of Mikes boots,, on my 75 XS,, they lasted some 200 miles...
One cracked on the side, due in my opinion that they may have been older generation boots, as they just looked "rubbery" ,
but I feel 99% of the crack in the side (which let air in) , is due to the local Md Bonsboro bike shop, did NOT know, to use my old Yamaha shrouds to help support them.
(nothing to do with Ethanol )
NOW, I have only run the 75 XS, with new 2nd set of Mikes boots, and my old shrouds, for about 100 miles now, so it it too soon to tell for certain.
I have always had aftermarket air filter- pods, on both bikes...
I feel Mikes did fine by me, replacing them within 4 days of first e-mail, to my house, free of charge...
BUT if i were Mikes, i would state in the product summary, or assembly instruction, if you do not use the stock air boxes (which provided needed support) "you must use stock shrouds", around new boots.
( AND yes, you need to file or grind a little slot, in the metal shroud for the vacuum barb,,, BUT be sure to match left to left, right to right FIRST, or you end up with two nice little grind areas, on the old shrouds )
regards.
PS , after looking at JBM units on line,,,, there is NO doubt they are more stout... and if I ever need another set, it will be those.
Preston

[grizld1]

Right, Preston; unless you're using JBM's with their heavy-duty flanges, the shrouds are very important; they not only provide support, but also distribute pressure around the flange. If you're going to retorque (I've never had reason to), do it after cool-down; in my experience, overtorquing causes more trouble than the reverse.

Your local shop should have known better, but breakdowns were reported in installations with and without shrouds, with and without air box, for a couple of years. I've held the offending product in my hand, and the material was much lighter and less rigid than new OEM or Tour Max. It's interesting that in spite of complaints, Mike's XS didn't offer improved boots until the JBM product hit the market. Coincidence? Maybe.

[cros36]

has anyone used his Diaphragms?

[grizld1]

I haven't used the diaphragms myself (no diaphragms in my carbies), but I've heard much good and no bad from those who have. Don James' specialty is parts for ultralight aircraft, where selling problem parts will put a guy out of business (and also out of everything he owns!) in a hurry; the man doesn't sell junk!

[ShakerNorm]

Cros - I have a set of Don's diaphragms in my 79, and haven't had any problems, yet (except installing them - they go in VERY tight - but need to to make them seal properly). Of course, we can still run gas without ethanol in it, and that's what I run in mine. If I'm right, he probably uses the same formula rubber in the diaphragms and carb boots, so there shouldn't be any problem with them.

I'm a happy customer, and if I need new boots for my bike, Don will get a repeat customer!

[cros36]

just called my order in for the holders and diaphragms. very nice guy. excited to get them in.

[dogbunny]

Okay, I just received a pair of the angled BS38 JBM carb boots.
Are you guys using a gasket when you mount them? What about Yamabond or sealant?

I called JBM and asked Don, but he did not have a definite answer. He said they were designed to not use a gasket, but that he doesn't actually use them, so he doesn't know if a gasket is needed to make a seal.

Thanks in advance for any input...

[billychop]

I'm not sure if you NEED them, but I had a new set of the stock ones and they worked with the JBM ones. I would use them if I were you, but I have a motor that I don't want ANY gas on too so take it for what it's worth.