carb boot repair

Hello guys, I have just gone through and cleaned the carbs. My carb boots were cracked and needed to be replaced, but with the prices of new ones ($250ish for 81-83 xj650j)I chose to repair them. I was also concerned about how they would look as I am one who likes things to be done right and look good. But I have little money left after the reviving of this bike and need to stretch my lasting few dollar bills. I found a little info about some who used silicone and bicycle tubes with success. It did in fact work very well, here is what I did in detail.....

Before... (actually after I blew out the excess oil)



Items used:
-1ea. per boot: 2.25" bicycle tube cut into 1.5" sections with a very small hole punched for the vacuum tube. (walmart $5)
-Permatex Clear Silicone RTV (walmart $5)
-2 foam brushes (I work in the medical device industry for for me free, but i'm sure any small foam brush will do)



1. Soak the boots in oil. This helps revitalize the rubber. I soaked them for about a week (mainly cause I didn't have time to get back to them)

2.Drain then oil from them, wipe off the excess, and for best results use a air hose and blow out all the cracks.

3.Use Permatex RTV clear silicone. Apply a thin coat making sure to get in all the cracks good. (Stress the boot if necessary) let dry for at least an hour.



4.Apply a thin second coat. Let dry for about 30 mins.

5. Stretch over the bicycle tube and smooth out. Helps to fold the tube in half and fold back after it is on the boot. this is a bit tough to do and the silicone will still be a little tacky (which is good for the tube to adhere to the boot) Let dry minimum 24hrs.



6. Done! Cost new:$250ish Coat repaired: $10ish




I hope this helps anyone who either cannot afford to buy these new or cannot find new ones (as they are apparently getting more and more scarce) Good luck and happy saving

 

NICE!!
Have you run these on the bike yet?

 

nope just finished doing this today at work. new jets should be in today (2 steps up .110 to .127) then just waiting for the rest of the gaskets and a few other parts to arrive. lastly the tank and side covers are being finished in prep for paint (going metallic black with candy electric blue ghost flake)

 

Just a heads up on the inertube, if you ever tried to cut old tubes into big rubber bands, they don't last long. They last a long time in a tire but not out. Iam thinking maybe It's UV light, how about a coat of paint or a wrap of tape ?

 

Good thought, I did forget to add that I will regularly clean/coat them with armor all.

 

On Manifolds that are deemed salvageable:

1) I fill the crack with Black Silicone.
2) After the Silicone has cured I coat the whole Manifold with Liquid Electrical Tape.
3) The Liquid Electrical Tape dries VERY quickly.
4) After the L-E-T has dried, ... I Sand the Manifold smooth with 400 Wet-O-Dry to remove Pulls and Wrinkles.
5) I dump several drops of Black Nail Polish on to a 3X5 Card and use an Artists Paint Brush to apply a smooth Coat to the Manifold.

Use fresh 3X5 Cards while applying the Polish.
Unclog the Brush with Carb Cleaner.

No leaks.
Looks great.

 

Rick,

When reinstalling repaired intake manifolds, do you suggest adding black RTV as a gasket maker? When I removed mine, there was some beige silicone looking goop applied to the metal mating surface of the manifolds.

 

Great looking boot repair - - just questioning the need to go so "fat" on a 650 ?? Most people would try 112's or 114's.

Back to the boots - make sure you get a good seal to the head - the slightest debris there causes a leak.

 

There should have been a gasket there.

 

Most Bikes have BOTH a Gasket and an "O-ring type" sealer.

There was no sealant applied.
The O-ring was relied upon to make the Joint Air-tight.

Bikes which have never had the Manifolds removed often develop an "Occult Air Leak".
The O-ring ages and begins to allow Air to slip-by at Higher Revolutions and does Not Leak when the Manifold Vacuum is low.
"Hiding" from Propane and Starter Fluid detection.

Because many of the soft Manifold-fastening Allen Cap Screws are seized, ... the Fasteners seem to be fully tightened.

On Manifolds that have been able to be removed without seized fasteners preventing their removal, ... I use a Stock Gasket as a Template for making a New Gasket from a Pressed Cork Sheet or Thick Fiber Gasket Making Sheet.

I treat BOTH sides of a Newly made Gasket with Indian Head Gasket Shellac or Permatex 1-Minute Gasket Maker.

On Manifolds which have Fasteners the LEAST BIT resistant to being removed, ... I treat the Manifold as having SEIZED Fasteners and don't attempt to loosen them with force.

On Manifolds with SEIZED Fasteners, ... I fill the Gap between the Manifold and Head with Black RTV Sealant. I Squeeze a small amount of RTV onto one of a supply of 3X5 Cards and fill-in the Joint using an ample supply of Wooden Stir-sticks that followed me home from Starbucks.

It's easier to Fill-in the Manifold -to- Head gap with the RTV Sealant and Dress the Outboard Manifolds to be cosmetically attractive ... than it is to stubbornly attempt to remove a Seized Fastener ... have it break-off ... and render you way-way up that proverbial odious creek, in a rickety flat-bottomed boat, unfortunately totally absent, and desperately in-need of any means of achieving mobility.

 

+1 on that, it can be very hard to detect and could cause all sorts of false "carb faults". My bike ran fine as it was but I decided to make new gaskets just because the intake boot bolts had already been replaced & it was "right" to have new gaskets there... It runs even better now, got to do the running sync all over again though :lol:

I used a gasket dressing on both sides of the new gaskets too.

 

Crap, another thing I have to look at this week.

Will you guys please stop thinking of repair possibilities on these bikes?

I bought a tube of Permatex gasket maker and Black RTV last fall, and haven't opened them yet. It was a sacrifice to the XJ gods for a problem free year.

Now you got me questioning my gawdang faith.

 

Thanks guys. I'm so close to getting this thing running right. I know it's worth all the hours.......

 

So I forgot to ask: since I don't have a stock gasket, when I make my own, should the gasket extend to include the area where the allen screws go into the head, making it oblong, or just a circle around the intake area?

 

Yes, you make the new gasket by tracing the complete "footprint" of the inlet boot.

Ideally you want to mark out all 4 and cut/punch the bolt holes & intake holes before you cut them out of the sheet, that way it's a lot easier to do without inadvertently folding/tearing the gasket paper...

 

A 9MM shell makes a great punch (except in the UK and OZ )

 

I dunno, I have a Walther P88 compact so could try that hahaha

I think a better option for our shores though would be the old cylinder head dowel I used, less chance of bother with the friendly local TAC team 8O