3 safety/performance related questions (tire and fuel line)

Ok, I have three questions. Let me first apologize in advance for such a long post.

Question 1:
Is there any negative side effects (safety or performance wise) or carb issues if I use a 3/16" fuel line (it's the closest size the local shop has) as opposed to the factory 1/4" fuel lines? The PO put on a 5/16" line on it for some reason (I'm guessing that's why the spark plug ends were solid black when I changed them). But according to him it ran fine, it was his daily driver. And I was able to get the bike to run for a few seconds when I first bought it (I'm doing carb cleaning as we speak). To be honest, I'm not very mechanically knowledgeable (but I'm slowly learning thanks to this site ), but I'm afraid the 3/16" won't deliver enough fuel to the carbs, becuase it looked to me (from the black spark plugs) like the 5/16" was causing it to run rich (is that the right word?) plus I don't want to create an unsafe condition or performance issue for my bike. It has enough of both of those already. The more I dig into this bike, the less of a "great deal" it becomes, Caveat emptor indeed.

Question 2:
My project bike has rear tire without the proper amount of tread (actually it looks more like a racing slick at this point). I want to be safe and it definately won't past inspection so I need to replace it. However I have a rear wheel from an 550 Maxim that has the same size tire on it. It has excellent tread, in fact it looks almost brand new. But as luck would have it, it has leak in it somewhere (or maybe it's just not mounted correctly, is that possible?).

My second question is, if I can pinpoint the leak, is it safe to just plug or patch it and put in on my riding (hopefully soon to be, thanks to all you guys/gals) bike? It's got plenty of tread and I'd hate to see it go to waste. Plus, I don't want to spend more money than I have too, but I'd much rather bite the bullet and buy a new tire than to be riding around in an unsafe condition. This is a pretty serious question to me, so please only answer this one if you know for sure.

Finally...

Question 3: Is it safe to use the screw type tube clamps for the fuel and vacuum lines instead of the factory clamps (another PO modification)? Our local Autozone carries almost nothing I need for my bike or motorcycles at all (they should change their name to Car/Truck Zone). In fact I haven't found one single Autozone (I've gone to about 5 different locations) that has the 82 xj750 even listed in their computer, although they all had the xj550, xj650, and an xj700(?) and a few others listed. Thank goodness for people like chacal.

Sorry for the long post. I had an even greater lack of knowledge didn't ask enough questions when I bought it, so I'm making up for it now. If you know the answers to any one (or all) of those questions, I would greatly appreciate your advice/help. Thanks in advance. I guess that's all for now, I need to get back to those carbs....

PS
(Does anyone here live close to Forney TX, I do computer & network work for a living so maybe we can swap favors or a couple cold ones for some help on my bike project)

 

The Fuel Line diameter is not a problem. Be sure the Hose clamps are tight.

The tirre might be fine. Might not need a plug. Cold weather lets the air out from places along the inside of the tire that have become oxidized.

Clean the area where the tire will seal to the wheel with a ScotchBrite Pad.

Worm gear Hose Clamps are superior to Speed Clamps.

 

I'm going to air up the tire , then hose it down and see if I can find a leak, if not, then I'll try to put it on my 750's rim. I'm sure it'll be simple (yeah right). If it is a leak, it's a very small one, because it takes a few hours for the tire to go flat after I inflate it (when the bikes on it's center stand). I've had small leaks plugged in my cars' tire before, I just don't know if it would be an issue with my bike. Has anybody plugged or patched a leak in their motorcycles' tire(s), or do you just buy a new one?

But you don't think the smaller hose diameter might be a problem during acceleration? Again, I'm far from a mechanic, but it seems to me, that's when it would lead to a lack of sufficient fuel to the carbs. But I'll go with it anyway, wost case scenario, the engine shuts off or won't start, and I'm sure I can find the right hose diameter somewhere later on there's an O'Reilly's close by I haven't checked yet.

With the screw on clamps, my big fear was that the could cause a leak in the lines if tightened too much. Although at the same time, I agree they seem to be superior because you can get a tighter and more secure fit. But again, that would be easy to fix if it did cause a leak.

Thanks for your help!

 

Re: 3 safety/performance related questions (tire and fuel li

Check the valve for the source of your leak too. I've got one leaking down slowly that I'm pretty sure is at the valve.

If it's the tire I'd be more inclined to use a tube than to plug it.

Oh, your plugs are not fouling because the fuel line is too large diameter. Your problem there is at the carbs.

 

Re: 3 safety/performance related questions (tire and fuel li

Carbs feed fuel through the jets, which take their fuel from the float bowls. Very unlikely that a smaller diameter fuel line would not be able to keep the bowls full even under hard accelleration. Even on my Buell (with one carb, one float bowl) I can ride for a few minutes with the fuel off before the engine quits. (don't ask how I know this)

Clamps are clamps. Either they seal, and don't leak, or vice versa.

Your back tire is all that keeps you connected to the tarmac. At any given moment your "contact patch" is the size of a postage stamp. Couple that, with the fact that even a few pounds pressure difference can be the difference between excellent handling and uncontrollable, plus the fact that you can pick up a new economy import tire for less than fifty bucks, and it's a no-brainer to me. The used tire is used. The rubber has hardened and deteriorated, to extents unknown. Buy a new tire and ride with peace of mind.

 

Re: 3 safety/performance related questions (tire and fuel li

Yeah, I know the carbs needed a good cleaning at least, if not a total rebuild (but man I hope not). I was supposed to clean them today, but after reading so much about carbs in what seems like most every post in this forum, it's suddenly got me very intimidated and feeling overwhelmed and unprepared, now that the time is at hand.

This morning when I woke up, I figured I'd be starting up my bike at this time tonight, and adjusting the purr to perfection to the envy of all my XJ-less neighbors, but I didn't even get them pulled out of the frame yet. I have a set of Mikuni's (sp?) already pulled from my 550, but I really can't practice on them because the 750 uses Hitachi HSC32's. My parts 750 is sitting in the bed of my truck at an auto repair shop because of a fender bender I got into. So, hopefully tomorrow I can work up the courage to actually make some progress on the real ones.

I'm using the Haynes manual as my guide. I've used the Haynes manual on every car I've ever owned, so I have faith in that it's usually spot on. But I know about the error on page 123 (Fig. 7.9b) where it confuses the main air jet with the pilot air jet. If these carbs can confuse even the all mighty Haynes, what chance do I have of making it work properly. But is there any other special information I should know to before I begin? I've armed myself with various sizes of wire brushes, screwdrivers, and a can of carb cleaner. Is there any other info or supplies I might need? Maybe a small sacrificial animal to appease the carb gods?

 

Re: 3 safety/performance related questions (tire and fuel li

Captainkirk: Thanks for the sound advice. That's exactly what I'm going to do. I'm even going to get a new one for the front, even though it appears to be fine. If you only could see half the stuff the PO did to this poor bike, it'd break your heart (and make you want to replace every nut, bolt, wire, and gasket on the bike). Are there any advantages/disadvantages on getting a tube or tubeless tire(s)?

 

Like the late Howard Cosell used to say:
"Just tell it like it is"

You need the RIGHT Toolls for doing Mikuni's ... especially; Mikuni.

If you don't have a Screwdriver that FITS the Jet Slots and start removing stuck Jets ... you'l be drilling-out Jets before too long.

Sure there's a little difference inthe way they are built and configured ... but, Mikuni and Hitachi are prety similar when you get right down too it.

READ my "Cleaning your own Carbs; The whole nine yards" Post, before you start-in on the Mik's.

http://xjbikes.com/Forums/viewtopic/t=2 ... yards.html

 

Re: 3 safety/performance related questions (tire and fuel li

Collins, man, we're in the same boat. I think I got my bike around the same time as you. You might have noticed my string of bewildered posts on carbs for the last month.

But just to throw some more encouragement at ya, it's actually really fun once you get in there. It's just sort of a different mindset, you forget that you want the bike to run RIGHT NOW, and just explore the carbs. Cleaning them is actually kind of satisfying. And they're not nearly as fragile as they seem to be.

But if you do break something, chacal sells a lot of aftermarket parts that are WAY cheaper than the dealer. I paid twenyt-some bucks for a main jet that I believe the chacal sells for seven. And so on.

 

Q-1 1/4 inch fuel line is very common. Check your float levels could be high.
Q-2 The problem with plugging a bike tire is the damage to the belts or cord of the tire. The reaming tool makes a larger weak spot. My mechanic installed a tube. And I can plug a tire blindfolded.
buy new tubeless tires. tubeless runs cooler.
Q-3 Worm screw clamps rule. There's almost no fuel pressure--with new line, you could run clampless.
While cleaning your carbs, make sure these 4 jets are clean; Pilot jet in float bowl, emulsion tube that sticks into float bowl, it's little side jet, and the primary, next to the main. Carefully run a wire from a wire brush thru each and chase with carb cleaner.