My 1974 R75/6 story

[crazydrummerdude]

Drained the tank; took the carbs apart (sans choke and diaphragm); cleaned it up; no difference.



"fart-fartfart-fart"

Stock ignition, btw..

 

[AnnapolisAirhead]

hmmm....tank lining peeling off like slabs of week old oliveloaf balonie clogging the petcocks?

Maybe run some seafoam through it for a full tank.

 

[godfather]

Have you checked coils for cracks or loose connections, plug wires for broken or corroded connectors, plugs themselves for burnt off electrodes or cracked porcelain?

 

[crazydrummerdude]

Well, it turned out to be pretty simple.

I wasn't too concerned or rushed to solve it, but I told a GS owner/advrider guy I work with, and he came over to get a feel for the problem. To give us a baseline, I checked the valves on one side while he checked the carbs on the other. All good. Pop off the front engine cover and immediately see that there's no points gap.

Gapped, checked the timing, adjust the idle, and I'm back in business.

 

[crazydrummerdude]

Ahem..

 

[20774]

Goin' Russian on us, there Nathan!!

 

[crazydrummerdude]

Goin' Russian on us, there Nathan!!

Yeah, man.. er, should I say.. da, droog! It's just my username in Russian; I thought it looked cool. Same reason I taught myself it at 16.. but have since forgotten almost everything useful.

dobrey din.

Here's a few more pics.

 

[JohnW67]

Shieldless

How was it riding long distance without a shield or faring? How many miles/day?

 

[crazydrummerdude]

It was fine by me. I've never ridden with either, although I have a brand new Givi windshield sitting on my shelf waiting to be tried out if I ever feel bored.

While in California, I did about 1000 miles/weekend every weekend. Sometimes they were 3 day weekends. So, 3-500 miles/day. Fourth of July was a 4 day weekend, and I did 1700 miles.

 

[kmkahuna]

And what a story it is....

This photo of yours is classic....

 

[crazydrummerdude]

This photo of yours is classic....

Ha. That's on Angeles Crest (2) westbound, after turning from Fort Tejon Rd, I think.

I heard that 36 between Fortuna and Red Bluff had a "140 miles" sign. The night before I went for it, I met an advrider at a gas station, and he said "Yeah, we just did 36!" Cool, I thought. Well, nope, the road was boring. Heck, I just found this website while I was posting this response. Those guys must have been on a different 36 . The first, last, and middle 40 miles were boring. So, 140 - 3*40 = 20 miles of decent riding.. and in those 20 miles, I had 3 "locals" try to run me off the road. Where's the amazing part?

I guess I should have gone the other direction to get a pic of the sign, oh well..

 

[crazydrummerdude]

I bought the large tank with a crappy rattle-can job already on it. It's pretty much toast, so I'm repainting it.

Based on my experience of blowing out a hole in the bottom of a spare dirtbike gas tank, I used a chemical stripper to investigate the structural integrity before sandblasting it. No pinholes and only 2 small dents to pull out.

Both exhaust valves are pretty much toast, so I am redoing the heads.

 

[lmo1131]

I found your post a little late...

My backyard; PCH (Highway 1) about two miles north of Cayucos, California. In the background; Morro Rock (on the right), Bishop's Peak (in the distance to the left (San Luis Obispo twelve miles further south on 1)).

Looks like it was a great day for an assault on Big Sur!!

 

[crazydrummerdude]

Both exhaust valves are pretty much toast, so I am redoing the heads.

Haha, wow!

 

[James.A]

That is exactly what the valves looked like on my 750 before I did the un-leaded conversion. Do not use Black Diamond valves with OEM type bronze guides. That error caused me to do the job twice.

 

[lmo1131]

I haven't kept current on the text in this thread ... is that what a "recessed" exhaust valve looks like as a result of unleaded fuel?

 

[crazydrummerdude]

I haven't kept current on the text in this thread ... is that what a "recessed" exhaust valve looks like as a result of unleaded fuel?

I would call that "extremely recessed."

I plan on going all-OEM on these heads. My R90 got Black Diamonds.. I hope they don't cause any problems.

 

[Geoff]

I would call that "extremely recessed."

I plan on going all-OEM on these heads. My R90 got Black Diamonds.. I hope they don't cause any problems.

I'm in the same boat as you crazy. I had my heads rebuilt by a reputable shop and was surprised to learn that OEM valves were not used, but rather the cheaper (more inexpensive) one-piece Black Diamonds. Supposedly if you use the correct guides as stated by James above, this will eliminate some issues associated with the one-piece BD's. There was a furious debate over on the ABC list recently, about this same topic. A good read if you really want to get into the pros and cons. My feeling is that if I can get 100K or better out of the BD's, I'm doing well. I don't think there is much chance of a premature failure assuming they were installed with the right guides, but what the hell do I know?

 

[typ181r90]

Tom Cutter rebuilt my heads using the black diamond valves and I've got 2k on them so far with no issues. He actually talked me out of using OEM valves

 

[20774]

Ted Porter was one of the first people to use the BD valves when he worked for Bob's BMW probably 20-25 years ago. There were some teething problems. I believe Ted found the part of the stem that went through the guide to be the problem...too rough, not the right clearances. Even if the BD valves are in their 2nd or 3rd generation, after reading the back-n-forth about valves, I'll still use OEM...Ted Porter will be doing my heads.