rubber intake sleeves

[richard100t]

I decided to finally replace my rubber intake sleeves. The stock items were cracked & looked shot. I was thinking that my tb's needed balancing as my bike would have a mild cough or backfire at around 3000rpm occasionally. Also the bike was slightly hesitant to start. Long story short, I replaced the sleeves & those minor issues dissapeared. I guess there must have been a slight air leak in the sleeves after all. I got the sleeves at MG Cycle for about $32 or so. Fast delivery too btw I sure hope the new ones are a better quality rubber than the oem ones.

[Skeeve]

I sure hope the new ones are a better quality rubber than the oem ones.

87642[/snapback]

 

Rubber degrades when exposed to heat & solvents. Do yourself a favor: before installing your new intake boots, spray them w/ silicone spray: it will help protect them from oxidizing & they'll last that much longer. This is also something you should do annually for any rubber parts exposed to the weather on your bike or cage; it really does help'em last. A $4 can of spray silicone can save you a lot more than that in saved time, expense & frustration.

 

Glad to hear you found a solution!

[richard100t]

Rubber degrades when exposed to heat & solvents. Do yourself a favor: before installing your new intake boots, spray them w/ silicone spray: it will help protect them from oxidizing & they'll last that much longer. This is also something you should do annually for any rubber parts exposed to the weather on your bike or cage; it really does help'em last. A $4 can of spray silicone can save you a lot more than that in saved time, expense & frustration.

 

Glad to hear you found a solution!

87644[/snapback]

The thing is my sleeves looked cracked & weathered last year when I bought it. The bike only had 315 miles on it then, thats why I think the oem parts were of poor quality. The bike had just sat in an attached garage under a bike cover for four years. Maybe just sitting there ruined them?

[Guest ratchethack]

IMHO, most of the cracking is cosmetic only. I was concerned enough about this two years ago to have bought a new set to keep on hand for the time when I could notice any leakage, at which time I'd replace 'em. I've kept a pretty close eye on it, and there's no evidence yet. Ozone and other oxidants in the air have this effect on many compounds. I've kept the new ones sealed up in plastic to prevent 'em from becoming unused, pre-broken parts...

 

Some shrinkage of the material of the boots is to be expected. This will cause the clamps to appear to have loosened. They can be (and should be) periodically tightened -- just firmly, not too tight! -- to prevent leakage.

 

I'd be very careful what kind of "magic" preservative you might be tempted to put on these. By my experience, products like Armor All, (for one) can actually speed up decomposition of many kinds of soft compounds over time...

[Mike Stewart]

I agree with ratchet, many preservatives will make the rubber look good now but will actually aid in the decomposition of the rubber. This even includes silicone. I work as a GM car tech and they have been telling us for years not to use silicone on the rubber parts for squeaks etc. They came out with a special lube in a one ounce bottle that cost a wopping $80.00 for use on rubber weather strips

 

Also, at least in automobiles there is a green house emission test which the car is placed in a room and then measured for emissions of the car parts. I have heard the cars are cleaner than a pine tree Anyway, they had to take out a few chemicals in rubber which makes them not last as long.

 

Or it could be because of the Ozone

 

Mike

 

 

 

IMHO, most of the cracking is cosmetic only.  I was concerned enough about this two years ago to have bought a new set to keep on hand for the time when I could notice any leakage, at which time I'd replace 'em.  I've kept a pretty close eye on it, and there's no evidence yet.   Ozone and other oxidants in the air have this effect on many compounds.  I've kept the new ones sealed up in plastic to prevent 'em from becoming unused, pre-broken parts...

 

Some shrinkage of the material of the boots is to be expected.  This will cause the clamps to appear to have loosened.  They can be (and should be) periodically tightened -- just firmly, not too tight! -- to prevent leakage.

 

I'd be very careful what kind of "magic" preservative you might be tempted to put on these.  By my experience, products like Armor All, (for one) can actually speed up decomposition of many kinds of soft compounds over time...

87677[/snapback]

[mike wilson]

I agree with ratchet, many preservatives will make the rubber look good now but will actually aid in the decomposition of the rubber.  This even includes silicone.  I work as a GM car tech and they have been telling us for years not to use silicone on the rubber parts for squeaks etc.  They came out with a special lube in a one ounce bottle that cost a wopping $80.00 for use on rubber weather strips

 

That sounds about the right sort of price differential between over the counter and OEM silicone. But I'm just a hardened old sceptic.

[O2 V11]

This "cracking" of the inlet sleeves must be prevalent. Mine arrived as such in July '04, with the bike being assembled in Feb '02 and having travelled only 6 miles. I am of the opinion if it isn't broken then there is no need to fix it. The sleeves appearance has not changed at all since then in 7,000 odd miles. Never has there been any indications of them actually leaking air. This leads me to believe mine is only cosmetic damage.

Rob

[Erikw]

(long-ish post, its been awhile..)

 

I just ordered left and right boots from MG Cycle, around $32 for the pair, four in stock. Very nice. Interesting, the local guy quoted $99 for one, with none in stock and wasn't sure he was looking at the right part. I'm 0 for 2 with them but will keep trying so support the local guy.

 

Regardless, I've put about 7k mi. on my 02 LeMans since getting it in April a few months ago. It had popping in and coughing issues the whole time and the left boot was blown off its mounting collar at the head twice.

 

I over-tightened clamp the second time in an effort to make it stay. Seemed fine for commuting to work and around town.

 

Then came my big cross-country ride in July. All was fine until we hit record heat in the desert, 122 degrees down on I-10. Unbelievable.

 

The heat was too much for the left boot, and it tore itself beneath its front clamp. This made the coughing and backfiring much worse. I patched it as well as I could with black RTV silicone, which didn't work very well if at all.

 

I babied the bike home, checking temp on the cylinder heads with my hand to be sure the left one wasn't a whole lot hotter than the right one due to lean running. It seemed ok. Highway running was fine, low speed stuff was full of pops and backfires. The bike got me 3k miles home without complaining, I just hope I didn't kill it in doing so.

 

Hopefully fresh boots will solve most if not all of the popping coughing and hiccupps from before. I will let ya'll know. I want to preserve these boots some way some how from cracking in the near future. It also seems wise to have a backup set on the garage shelf wrapped in plastic. Having them should mean I'll never need them. That's how it usually works, doesn't it?

 

btw, Thanks for all the info everyone has provided. I have benefitted tons from all the knowledge everyone shares here!!!

 

Erik

[todd haven]

Long running joke:

Guzzi put the Vatican in charge of rubber products==

ergo, they don't hold up real well

 

The part number has changed, I can tell no difference in the new vs. old.

 

I don't like silicone as a preservative, either.

You folks in Europe, specifically avoid silicone,

it does bad things to O2 sensors.

 

If it was an ozone problem, why would the

TB to intake boot outsell the

airbox to TB boot 6 to 1?(pulling numbers out of my arse,

but you get my drift)

[stormsedge]

Replaced my boots about two years or so ago when bike began to display poor performance and boots looked pretty cracked. Quick check to separate cosmetic from functional is to spray the crack with a little carb cleaner when the bike is running...you will immediately know if you have a real crack. That said, when laying my bike up in March, before this latest odyssey, I noted that the boots are cracking again. During previous reassembly, noted that the line-up of the injector body and intake horns is not as good as it should be, so that stress probably adds to the deterioration (plus that Guzzi vibration). Anyway, will replace again at tear down upon my return. Keep smiling. k

[Ouiji Veck]

Better to have a boot blow off than bend a throttle plate!

Don't over tighten them.

My beemer buddies manage to find radiator hose/ or some alternative.

I KNOW they have Guzzi genes in them somewhere.

What about greaseing them up with vasaliene?

[quazi-moto]

Does MG carry both types of boot, or just the front (TB to intake) boots?

[Alex-Corsa]

I'd be very careful what kind of "magic" preservative you might be tempted to put on these. By my experience, products like Armor All, (for one) can actually speed up decomposition of many kinds of soft compounds over time...

 

I use vaseline for that, it does well with these rubber lube.

Thoguh tere are also different qualities on these intake rubbers.The best ones are the ones I have now , bought them from Agostini and after almost a 9 months and many km's look like new.The worst were from 'twins and parts' shop in Germany where after 2 months of wearing them cracked ,one of them was cut!! although all got the same good reatment. from me-