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Post by **Admin** » Sat Jan 14, 2006 9:29 pm

I took my Buffalo out for a 50 or so mile ride today. This is the farthest I have gone at one time so far. The bike runs great and pulls like a tractor from just about any RPM. What impresses me most is that I can roll it on from about 3K in top gear and it just pulls away. My H1 would probably stall if I tried that. I had two observations that I need opinions on.

1. It has some minor surging at trailing throttle, especially in the lower gears. It is not real bad, but is noticable. Is this typical or does it need to be tuned out, and if so, what is the sequence to follow to tune it out. It has stock pipes that have just been cleaned out and had new packing in the baffles, everything else bone stock as far as I know.

2. Sometimes when I come to a stop the engine idles at about 2K for 10 seconds or so and then slows down to 1500 and idles there very smoothly. It does not always do this, sometimes it idles down to 1500 as soon as I stop. It does not just rev wildly like an intake leak, but I have sprayed WD40 around the intakes to see if I could detect a leak and did not find one. I probably need to reset the idle down to about 1200, but I idled it up while I was synching the carbs and forgot to reset it.

Wayne

Post by **Admin** » Sat Jan 14, 2006 9:56 pm

There was a surging problem on the 74 models. A change to the carb airjets was supposed to fix it. You might be abe to cure it by going up one size on the pilot jets. The fast idle is usually cased by an air leak of some kind.

I suspect that one of my engines had a bad SRIS valve that was causing one cylinder to run lean. I was never quite able to prove it.

Lane

Post by **Admin** » Sat Jan 14, 2006 10:29 pm

I thought they all surged and bucked when you let off the throttle. I have Keyster pilot jets in my bike, 47.5's, correct for a '74 but one step rich for a '76 and it still surges. Do you have a little slack in the throttle cables, if you adjust all the slack out they will stick a little bit.

Post by **Admin** » Sat Jan 14, 2006 10:39 pm

Lane, if there is an air leak, why would the engine idle back down after a few seconds? It seems to me that if there is an air leak, it would exhibit a fast idle all the time. When I crank my bike up and let it warm up to operating temp here in the shop, it does not exhibit the fast idle condition.
In fact, it has never done it until I took it out today.

Do you still have the SRIS lines/valves on your bikes? How did you fix the one you suspected had a SRIS problem? I assume the SRIS valves are one-way check valves or something of the sort. Are they operated by engine vacuum?

Sorry for all the ? but its the only way I know to learn what I need to do.

Wayne

Post by **Admin** » Sat Jan 14, 2006 11:01 pm

I think I have enough slack in the throttle cables, but I will double check. The first time it did not idle down, I moved the cables around a bit to see if they were binding and it did not seem to make a difference.

Wayne

Post by **Admin** » Sun Jan 15, 2006 12:53 am

The SRIS valves are check valves in the bottom of the crankcase. They allow excess oil to move to the transfer port of another cylinder (one feeds to the intake on the left). I don't know for sure that mine stuck, but that cylinder always ran leaner, and eventually the SRIS valve came apart, and took a ride on top of the piston.

My stock 74 has the valves, I removed them from the blue one. I plugged all the holes by drilling to 8mm and installing allen set screws. I can't tell the difference.

A lean condition can cause your engine to "hang up" at higher rpm when you close the throttle.

My stocker surges some, the blue one doesn't.

Lane

Post by **Admin** » Sun Jan 15, 2006 10:45 am

I fixed the same "happy" idle problem which randomly affected my 380 after all the trials Lane says. At a stop light the engine hang up one more time, about 2000 rpm.... tired of this I put a finger on the RH carb arm, the one with the angled rubber boot, suddendly the engine slowed down to 1200 rpm! Then I changed the needle jets, cleaned once more the jet needles (by a phosporic detergent and compressed air), wrenched the whole things togheter and ...the idle is just it, 1200 rpm, almost instantly after the gas closing. I tought of an irregular needle jet wear combinated with a little resistant dirty in the jet needles inner. Maybe I was on the empiric side but... it worked fine!

Post by **Admin** » Mon Jan 16, 2006 3:21 am

Rocky, I have had the same problem ... pushing on the linkage a little brings the idle down to a nice 12 - 1300rpm

Post by **Admin** » Mon Jan 16, 2006 1:05 pm

The two currently running Buffaloes both cold start at 3K RPM idle, but after they're warm, idle at 1200 RPM. Anyone else's do that, or does everyone else's do that?

Post by **Admin** » Mon Jan 16, 2006 3:57 pm

Yes, Gordon, mine do about the same.

Lane

Post by **Admin** » Mon Jan 16, 2006 6:47 pm

Ah, thanks, Lane -- you know me; the Jewish mother and worrier about my Buffaloes.....

Post by **Admin** » Mon Jan 16, 2006 7:08 pm

Lot of my two stroke bikes take a while to settle back down to idle. If the problem isn't an obvious air leak, a SRIS valve sticking, or slide hanging up, I figure that the slide is slightly worn (especially after over 20 years) and that's how it's going to be....

Post by **Admin** » Fri Jan 20, 2006 5:29 pm

I received the report from my MRI today, I haven't been to the doc yet for an explanation:

L1-L2 subligamentous mid and rt. lateral nucleus pulposus herniation at L1-L2 producing moderate rt. anterior lateral extradural impression upon the thecal sac. No freely extruded disc fragment is seen.

L2-L3 dessication and slight bulge of intervertebral disc.

L3-L4 there is diffuse subligamentousprotrusion of the intervertebral disc without acute herniation. Mild degenerative hypertrophy of the facets.

L4-L5 there is a lt lateral extruded pulposus fragment in the spinal canal producing lt anterior lateral compressive effect upon the thecal sac.

L5-S1 there is dessication and mild diffuse bulge of the disc without acute herniation. Mild to moderate degenerative hypertrophy of the facets.

Disc narrowing and vacuum disc phenomenon are seen at all levels. Degenerative spurring is seen in the vertebral body margins. No fracture or destructive process is seen at this time.

Anyone have a clue what this all means. I know there are a few of you here with back problems, so I thought I would ask the docs here. I have been referred to a neurosurgeon, will have to wait until then for the official explanation.

Post by **Admin** » Fri Jan 20, 2006 5:42 pm

I have no idea what all that medical jargon means, but I believe in living in a state of hope that the good will prevail.

It sounds like you have a failing or fialed disc(s), and have been living with some serious back pain for some time now! The L1-L2, etc is talking about the disc between your L1 (Lumbar-one) and L2 Vertebrae. The Lumbar make up your lower back.
"Disc narrowing and vacuum disc phenomenon are seen at all levels. Degenerative spurring is seen in the vertebral body margins. No fracture or destructive process is seen at this time. "
I think the Degenerative spuring is when the bone rubs together wrong and creates bone spurs -- kind of like a bunion on a big toe... But the good part is the part about no fracture or destructive process at this time.

Keep us up to date! I am sorry you have been feeling bad.
-fang

Post by **Admin** » Fri Jan 20, 2006 5:43 pm

I can't read Latin so can't help much...

but isn't the golden rule...avoid surgery if you can at all costs.....

I have a bad back and it is hell......so sorry to hear that....also sorry I can't be of more help with the diagnosis....

Archived Posts

Buffalo tuning

Question for all you back patients...

well....