Topic: Re: New Member with a question/Re: AHHHHH DAMMIT, I NEED HELP!

[fuwad84]

Thank you very much, I have yet to take out the air filter, the previous owner claimed he had replaced it recently, but I probably shouldn't take his word up to this point. The exhaust is another possibility. The change in sprocket size from 42 to 38 did actually improve my mileage considerably, from 83 to 93 miles a tank, but that was before the electric ignition. Lemme ask, what mileage are you getting from your Hondamatic?

What air filter are you running?  I'm asking because some filters are being sold and OEM that are very, very restrictive.  I run a K&N with no problems.

Poor mileage can be caused by a number of things, some are:

• wrong sprocket sizes - running the motor outside of designed speeds
• chain too tight
• air filter too restrictive
• rider too agressive
• timing off
• ignition advancer not working
• low compression
• valves incorrectly adjusted
• exhaust blockages
• brakes dragging

I know some of this is a repeat - but it doesn't hurt repeating.  Other chime in with their ideas . . . .

[raymond10078]

I'm in the 40's.

What about the spark advance possibility?  Is your timing advancing as it should?  Do the advance marks line up properly?

In regards to this site - many people are plenty willing to help.  From what I've seen, the people that get the most and best help and those that provide the best, clearest explanation of their situation.  Not many will go back and search to find all of your past posts to help.  People that post a complete list of symptoms, actions taken (tests, new parts, maintenance actions), even repeatedly, get the best help.  I've said all this - because maybe you could try that.  Keep all of us informed on everything you do and have already done.

[fuwad84]

Hi everyone, sorry about the spazing out for the title, but I sure am quite a bit pissed off right now. Remember how like the first issue I ever had with my bike was the bad MPG? Well since that time I've installed a pamco electronic ignition system, swapped out my 42 tooth rear 630 sprocket for a 38 and had the carburetors professionally rebuilt by a shop that specializes in old motorcycles. After taking a combined 600 mile trip up north and back I come to find out that my bike STILL GETS 26 MILES TO THE GALLON! WTF! I've spent more money fixing up this thing than I have on my car, yet it still guzzles gas like its gonna be banned tomorrow. So I put in a call to the shop that had done the work and now I'm waiting for a response. Now here's the thing, right now my chain and front sprocket are worn. So I'm thinking of getting a 530 conversion. So my two questions are: 1.) What the hell could still be wrong with my bike? 2.) what size front and rear sprockets in 530 would you guys recommend?

I really need your guys help here, I'm at my wits end and am about to put this money eating black hole into a car crusher. 

[Mercuno]

Im no pro by far but from what I understand with any carb rebuild you need to adjust it after putting it back on the (vehicle) while it is running. I.E. syncing the carbs. just in case you havent already done that. If you have then on to the next probable symptom. hang in there though some of the pros will help soon

[Really?]

I do not know the last thread but are you chasing the wrong demon?

Brakes dragging, bad wheel bearings, low tire pressure....

[fuwad84]

I do not know the last thread but are you chasing the wrong demon?

Brakes dragging, bad wheel bearings, low tire pressure....

The rear brake used to drag a little and I went and took care of that, it just needed grease in the lever housing perfect now. The front brake used to squeak long ago and I took it apart and cleaned out a lot of crap that was in the caliper and master cylinder, now its good as well. I keep tire pressure at 40 psi both front and back and check it regularly. As for wheel bearing....well I've heard any strange noise coming from the wheels at anyspeed and can't really feel that much drag from either front or back.

[fuwad84]

Im no pro by far but from what I understand with any carb rebuild you need to adjust it after putting it back on the (vehicle) while it is running. I.E. syncing the carbs. just in case you havent already done that. If you have then on to the next probable symptom. hang in there though some of the pros will help soon

Thanks.

[raymond10078]

Does your timing advance properly?  Have you hooked up a timing light and verified that the advance is correct (by looking through your timing marks)?

This is a repeat question from the last time - but I don't recall the answer.

[MCRider]

What kind of mileage did the As get when they were new?

[MCRider]

As to wheel bearings, if they are original, I'd change them just because. Age and condensation cycles take their toll. They were only sealed on one side originally.

[MCRider]

What kind of mileage did the As get when they were new?

I found a site that has CB750A specs. Should get 15.6km/ltr. Conversion = 36.8 mpg.  I thought it might be lower than that.

So you've got some work to do. Sorry.

Going to a smaller rear can actually reduce mileage as it doesn't allow the engine to spin in its sweet spot. And increases the effort to accelerate.  With only 2 gears, that could be important. I'd go back to stock as much as possible as that gets 36mpg.

How fast were you cruising. Top speed of 85-90, so sweet spot should be around 60mph @ 5500rpm +/-

[Sam Green Racing]

It don't help much when you start a second thread when you allready had one with all the info that you had given plus all the things that you had tried before hand, you will end up getting the same advice from different people and people that have offered help will loose interest.
Copy and paste your first post from this thread to your origional thread, people will then know whats allready happened and where you are up to.
In your last thread, you got to the stage of changing the air filter, did you do it before your long ride?
Without looking back, did you ever do a compression test on the bike, chances are that the motor is worn and the speedo reading is not correct.

Sam.

[fuwad84]

The timing does advance like it should when revving up, so that's working right. The air filter was changed when the carbs were rebuilt and I haven't checked compression yet, I'll do that next and get back to you. However, I wouldn't think that an engine with only 9000 miles on it would be worn out? You guys are my last hope before I either burn this thing or put it on craigslist for a steal. 

[Sam Green Racing]

Like I said, the speedo reading could be wrong, could be a unit from another bike with not as many miles on the clock.

Sam.

[Bob Wessner]

Like I said, the speedo reading could be wrong, could be a unit from another bike with not as many miles on the clock.

Sam.

Good point. Know anyone with a GPS you can borrow to verify the mileage after a fill-up, then refill and check gals/liters against GPS miles.

[fuwad84]

Like I said, the speedo reading could be wrong, could be a unit from another bike with not as many miles on the clock.

Sam.

Good point. Know anyone with a GPS you can borrow to verify the mileage after a fill-up, then refill and check gals/liters against GPS miles.

Tripometer and speedometer is accurate, I've already checked em with the Garmin. Honestly Sam, I know that you're saying that the odometer could be inaccurate from being replaced but considering that 7000 is whats listed on the title when I bought the bike, wouldn't that be a bit risky for the original owner not to tell me?

[Sam Green Racing]

It is ilegal in the UK but in the US I've heard of some real dodgy goings on over there
I'm not sure what some people might try to get away with doing.

Sam.

[Bob Wessner]

Hey, we resemble that remark. 

[Sam Green Racing]

Hey, we resemble that remark. 

Ok Robert, you just do things differently over there that you would get locked up for over here

Anyway, fuwad has another 2 page thread on this subject.....  http://forums.sohc4.net/index.php?topic=93138.0;all  How dose one merg the 2 threads ?

Sam.

[Bob Wessner]

Merged.

[Sam Green Racing]

That's what I like about you Bob, you're so 

USA 1-UK 0.

Sam.

[fuwad84]

So how much you guys think I should sell this thing for on craigslist? All it needs is a new sprockets and chain.

[Really?]

I wonder if you are leaking fuel out of the overflows.  If not when you are stopped at a light but actually riding.  When I was trying to resolve the fuel out of the overflow tubes issue, I had noticed it would leak while I was riding.  Ran out of gas once too!

[fuwad84]

I wonder if you are leaking fuel out of the overflows.  If not when you are stopped at a light but actually riding.  When I was trying to resolve the fuel out of the overflow tubes issue, I had noticed it would leak while I was riding.  Ran out of gas once too!

I'm gonna put this thing on a center stand, rev it up and check for leaks just for #$%*s n giggles as its the only thing I can possibly imagine that could be causing the gas to magically disappear like it does. I'm also gonna take photos of this thing to and get it prepped up for selling, I'd kinda like a Kawa KLR 650 instead.

[fuwad84]

Nope nothing, time to sell it. Sorry everyone, but if this thing was a horse I'd have brought it out back and shot it long ago. I've dumped more money into it than I'm willing to admit and right now I just want to get rid of it and move on to something more reliable. If you know of anyone with a large displacement dual sport looking to make a trade than give me a holler.