Topic: First time carb cleaner

[BobbyR]

I remember Hondaman speaking about some white deposits resulting from the MBTE they used in the fuel at one time. Nothing I found dissolves it, so TT's advice is sound. You are better off with Scotchbrite than steel or other metals to remove deposits.

[TwoTired]

I remember Hondaman speaking about some white deposits resulting from the MBTE they used in the fuel at one time.

Could be.  But, I would expect the deposits to appear in all the carbs rather than just the one that got water/condensation in it.

[Deltarider]

I don't get it. This guitar string echoes on and on. What is wrong with stranded copper wire? You can twist it so that it is firm and still the copper will be softer than brass. Perfect! I've been using the same piece of (old) copper wire for decades. Why risk delicate jets with harder stuff? Why would you want uncertainty if you didn't ream them after all? 

[TwoTired]

I don't get it. This guitar string echoes on and on. What is wrong with stranded copper wire? You can twist it so that it is firm and still the copper will be softer than brass. Perfect! I've been using the same piece of (old) copper wire for decades. Why risk delicate jets with harder stuff? Why would you want uncertainty if you didn't ream them after all?

I've encountered jets that were so crusted/packed that I could hear audible laughing as a copper strand buckled under the stress a failure.  A steel string passed right through. With no damage to the jet orifice or the ramps leading to the orifice.
It's low risk using a steel string.  Particularly if you round off the string's tip beforehand.

It's not the tool, but the hand (mind) that uses it.

What's funny is that there are jet reamers commonly employed by racer to fine tune their jets.  How do they succeed?
http://www.racingplanetusa.com/carburetor-reamer-incl-handle-case-p-262-1.html?utm_source=google&utm_medium=google_merchant_us&utm_campaign=google_products_us&gclid=CMmimI3x0bkCFS6CQgodXnkAGQ#.UjgBTYVOTIo

[Deltarider]

Maybe they start using tools like
http://www.louis.de/_20455f4dc3ddbb801991aba1b795b04650/index.php?topic=artnr_gr&artnr_gr=10003888&lang=en
and then
http://www.louis.de/_20455f4dc3ddbb801991aba1b795b04650/index.php?topic=artnr&artnr=10003930
I've never used them.

[TwoTired]

I've never used a jet reamer set either.  But, I know those who have.
I did notice in my brief search that the smallest reamer found was .33mm, which is bigger than any of the pilot jets found on the SOHC4.   But reamers are hardened tools, as can be guitar strings.

One of the things that set humans apart from other animals is our ability to use tools to make tools.

[Deltarider]

One of the things that set humans apart from other animals is our ability to use tools to make tools.

Absolutely so (and still I pick my nose the way any ordinary chimpansee does.)

[magicmark1]

Welcome.  Post up some pics when you hit 5


Here's a good site for carbs tutorial

http://www.salocal.com/sohc/tech/tech.htm

Thanks for the site link! It was pretty insightful. I think I'm going to try doing it myself too.

[run-tmc]

Here is a pic of the bottom of carb #4. On the left is the brass plug that remained intact after too much time in the chem-dip. On the right is the passageway that is now open with the plug long gone. Is this the welsh plug you had in mind TwoTired? Looks to be about 6mm in diameter, I couldn't get my vernier caliper into it.

Has anyone else had experience knocking these things loose? If so, what kind of glue will work best to reattach the brass plug to the carb body?

Thanks again for the help!
T

[TwoTired]

Wait a minute.  The holes in the top of carb bowl chamber dome are part of the venting system, which normally interconnect bowl chambers of adjacent carbs.

Do you have the plug that "fell out"?  Have you investigated where the passage leads to?  Is it a blind hole?  The outer most carb only has one carb to link the vent to, and that's #3.  Now, if you had carb #5....

[run-tmc]

Thanks to everyone for helping me through the carb cleaning/rebuilding process.

TT, you were right on target with your comment about the welsh plug venting to the "5th carb," much to my relief.

I bench-synced using a 1/8" drill bit, which won't give me perfect results, but hopefully a decent starting point.

SLOWLY, but surely, it's coming along.

[BobbyR]

Thanks to everyone for helping me through the carb cleaning/rebuilding process.

TT, you were right on target with your comment about the welsh plug venting to the "5th carb," much to my relief.

I bench-synced using a 1/8" drill bit, which won't give me perfect results, but hopefully a decent starting point.

SLOWLY, but surely, it's coming along.

+1  Slowly but surely sums up this and other projects on these bikes.

[Jayelwin]

I swear by my ultrasonic cleaner. It's about the size of my counter top deep fryer (and looks nearly identical) and works great. Fill it with water and a healthy squirt of Dawn dish soap and a half cup of ammonia and let her run for an hour. It heats up the water to about 175 degrees and everything comes out looking like new.

[M.Harrigan]

Here is a pic of the bottom of carb #4. On the left is the brass plug that remained intact after too much time in the chem-dip. On the right is the passageway that is now open with the plug long gone. Is this the welsh plug you had in mind TwoTired? Looks to be about 6mm in diameter, I couldn't get my vernier caliper into it.

Has anyone else had experience knocking these things loose? If so, what kind of glue will work best to reattach the brass plug to the carb body?

Thanks again for the help!
T

I'm curious about this as well. I have an old set that I'm rebuilding and 1 plug is missing in the #1 carb and 1 missing in #4. Is this normal?
What did you find out run?

[run-tmc]

Yeah, TwoTired explained it to me. All four carbs are built from the same mould I guess, with those channels venting to the carb to the right if viewed from the riding position. Since Carb 1 does not have a carb "0" that would vent into its float bowl and carb 4 doesn't have a carb "5" to vent to, both have a vacant channel without a welsh plug. Part of the design!


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[run-tmc]

This is probably a moot post, but I wanted to provide a post-op video of the ol' girl humming along, despite only having bench synced. Nice idle and revs through the rpm range, but bogs if I go from idle right to full throttle. One issue revealed by the video is that smoke/dirty oil appears to be seeping from the back of the cylinder/tach cable attachment point respectively. I'm not too excited about either. You can also notice that I can't operate my camera properly, haha, sorry for the zoom problems.

If anyone is still interested in this old thread:
1. Initial thoughts on the bog experienced when going from idle directly to full throttle?
2. Oil seeping from tach cable attachment?
3. With my very limited information provided, smoke coming from back of cylinder?
4. Anything else that comes to mind from the video?

MVI 2115

Thanks again everyone!
Tom

[TwoTired]

If anyone is still interested in this old thread:
1. Initial thoughts on the bog experienced when going from idle directly to full throttle?

Normal for carbs with no accelerator pump, vacuum operated slides, or fuel injection.  Physics.   It should take up to one half remaining throttle twist without stumble, even under load in any gear, though.

Stock air filter?  Stock exhaust?  Stock pilot screw setting?

2. Oil seeping from tach cable attachment?

I haven't changed one on a 750.  But, I believe there is a rubber seal there that likely needs renewing.

3. With my very limited information provided, smoke coming from back of cylinder?

Only a very limited explanation.       Might have something to do with the the engine breather tube.

4. Anything else that comes to mind from the video?

Readjust the valves if the engine was at full temp during the video.  Or, check for exhaust header leaks.

Tappet inspection covers appear to need new orings, as well