Timing, Need Help

[stone Man]

Haven't been on the forum for a few years but recently began work in earnest on my '67 GTR 350 that's in pretty good condition with less than 5,000 miles.

This past couple weeks have been cleaning her up– especially carbs, fuel cock and electrical connections. Also adjusted point gap, setting them at 14. That seemed to be mid-range of the tolerances. I would really like to check/adjust the ignition timing but the service manual seems less than thorough and I have some questions for you forum members. What I don't understand is the location of the bolt that is removed that lets you see the timing marks. It says "front of the crankcase" but I have only a vague guess as to which one. Anyone help me locate that? I also don't understand the "timing bolt and pin." What is this? I don't have one. Can a conventional timing light be used instead? I have that.

My son and I have had this bike for three years or so. We prepped and and got her running after first getting her, and have run her just a couple times a year since then. Now, we want to do what's needed to make her a solid runner. When we're confident of that (and we mostly are) we'll go through the trouble of getting a title (we're in Ohio). Once we get a title, we'll be confident to invest more in the restoration.

As luck would have it, after cleaning the carbs, etc., I was firing her up today and wouldn't you know; the kick start fell off. The kick start arm boss just broke. Could be worse, of course. But I did get her going coasting downhill and popping the clutch. After a short run (it's 35 degrees here today) ran much better than ever before. Whoo-Ray!

Thanks for any advice you can give. I'm sure I'll be back more often now that I'm digging into the re-work.

[ziggy stardust]

http://bridgestonemotorcycleparts.com/index.php?topic=2832.0

Z

[stone Man]

Thanks, Ziggy,

Studied the photo, then took a close look at the bike,  but still not certain. First, is the bold in question on the photo the one that's upper center that seems to be machined below the bolt head?

The person who posted the photo says it's on the left. That would be left side of the front of the crank case meaning the left side of the rider's position, or left side when looking at the front of the crack case from under the bike?

Thanks

[stone Man]

On further inspection. . . . I see a bolt on the driver left side front of crankcase behind the left exhaust down pipe and just above the front engine mounting bracket. It has a red gasket under the bolt head. But it doesn't look like the photo in post linked to above. And I don't see anything like that.

[Bikenstein]

You have located the right bolt. I believe the link is showin a 175 or 200 motor. If you don't have the tool, you can use a drill bit that fits snugly.

[stone Man]

Thanks, Bikenstein,
So this is a static timing (if I have my terminology correct) procedure? Find the right sized drill bit, put it in the hole and turn the rear wheel until it drops into a hole on the crank. From there, just follow the service manual?

Thanks for the help.

[Bikenstein]

Right, but a dial indicator would be more accurate used in conjunction with a tester light across the points. Both are called static timing.

Disregard the above statement cause I wasn't thinkin about havin to use a degree wheel

[stone Man]

Hmmmm, In the Service Manual, I see a dial indicator that appears to be in the spark plug hole. Clearly, this could determine TDC, but I'm uncertain how a dial indicator would be of use in the hole where the timing bold is, not to mention how you'd mount it to get readings. Yes, it would rub the cam but what would that tell me relative to TDC or degree marks off TDC for timing purposes? I mean, don't see what good it would do to have your dial indicator drop into hole on the cam. What am I missing here?

[Bikenstein]

Don't put your indicator in that hole! The timing is set to 25 + 1-2 degrees B.T.D.C. as far as I can tell from the manual. Find TDC then back it up and adjust your points to open at the proper time. I've done this method on many bikes and found those that have timing marks on a rotor or crank have been off from the factory on quite a few. I made new marks and then used a timing light. I don't know if a timing light would show the slot in the crank on a GTR through that little hole or not. Reed or somebody could tell you that or I could check it out later. When I static time I use a multimeter on the diode setting with alligator clips. That way I can hear the beep when the points break while I'm watchin the dial indicator. Sorry about this suggestion, I wasn't thinkin about using a degree wheel

[stone Man]

OK thanks, this is now making more sense. Would be great to hear Reed weigh in. Based on what you are telling me, am I correct in thinking that using the hole from the timing bolt is unreliable and working off piston TDC is better?

Thanks again for your input.
 

[Bikenstein]

The timing hole will work fine but dialing it in will be more precise. I have found factory timing marks off (idle and advance)on brand new bikes up to a quarter of an inch (mostly Hondas). But I'm not saying this is the case with the Bridgestones. You should be fine by just using the crank notch.

[reed]

stone man,
Forget the dial indicator gauge for now, send me a e mail with you tel number and i will tell you how to set your timing.
Sometime tomorrow if that will help you.
Thanks.
Steve.

[reed]

David,
Which Honda did you find the factory timing marks off the most.
Thanks.
Steve.

[Bikenstein]

The 68 and 69 CB and CL350's come to mind as far as timing errors. How do you set your timing on the GTR's?

[reed]

David,
I set my timing static first, then after a few miles i will use a dial gauge to set up the timing etc.
But i do use a drill bit to locate the cutaway on the web and i use a ignition timing tester that
Uses sound when the points open and once the motorcycle is running i leave the points cover off
Turn off the lights in the workshop and i can check out the points and condensers for any severe
Sparking and burning on the points due to a possible condensers break.And on your Honda CL 350
I have had normal timing issues with points and condensers etc.
Thanks.
Steve.

[reed]

This is a picture of my dial gauge  i have had for years.
Thanks.
Steve.

[Bikenstein]

On the CB and CL 350's, the marks on the rotor were way off the recommended distance according to the dial indicator. After making new marks and setting with a timing light the bikes performed much better. The 68 350's had multiple problems that were mostly corrected by 69. I had to do the same thing to a 175 and some smaller Hondas as well as others. I made it a habit to check timin marks with an indicator instead of just relying on the factory marks.

[reed]

David,
I never had that problem back in the UK, i worked at a Honda Dealership but i always degree the cams in.
And that would make a big difference in the running of the motorcycle.
Thanks.
Steve.

[Bikenstein]

That's  interesting, I'd like to know how to degree the cams in. I worked at a Honda dealership, too. I never would have checked other bikes if it hadn't been for the one 350 that I bought. I was tryin to get it runnin the best I could and found the marks were off several degrees. It didn't make any noticeable difference in mine but a few other bikes had better acceleration and top speed. Not just the Hondas but others at another dealership I worked for too. I think we once got a service bulletin on one model but I don't remember. Had one 350 that skipped a little at  around 6500 rpm. A week and a half and hours of tuning, testing and hair pullin later, I found the starter solinoid shorting out because of a small almost undetectable vibration that occured at that engine speed only. I had set a glass of water on the motor and was runnin it up to 10 grand and back to show a customer how smooth the bike was and noticed the water shakin at 6500. I happened to have the seat flipped up and saw the starter cable where it connected to the solinoid arcing to the frame.

[reed]

David,
This is my degree wheel and i would check TDC before using the degree wheel.
This would bolt on to the end of the rotor because you would start off on TDC.
Thanks.
Steve.