tuning the timing gt380

All to do with wiring, charging or just trying to figure out whats gone wrong.

Moderators: oldjapanesebikes, H2RICK, diamondj, Suzsmokeyallan

Post Reply
fastbike
Still in the Driveway
Posts: 7
Joined: Sun Mar 22, 2015 8:31 am
Country: norway
Suzuki 2-Strokes: gt380

tuning the timing gt380

Post by fastbike »

Hey hey folks :)
Restored my gt380 approx 9 years ago. After the resoration the bike has run 937 miles.(1500 km). When i tuned the bike, 9 years ago, it worked perfectly. Suddenly, last year, the left cylinder stopped fireing. Thought it was time to make it run again and so i tried to do. I have been tuning everything according to the book. First, i ajusted the gap on points. Also, i used a 500 sandpaper to clean the points contacts to be sure it clean and flat. Used some electrical cleaner on paper afterward to clean away dirt on contacts surface. Then, when the points are ajusted and cleaned, it was time to adjust the timing. I took out the sparkplugs and used a gauge to make sure the plug fires 3mm before top by twisting timingplate.  I have connected a lamp to the points to see when it opens.( Coyote, yes, im using the lamp u sent me 10 years ago)
Ok, now down to my problem. Since the center and right points are ajustable there is no problem to ajust them correctly. The problem is the left point. The left point is fixed to the timeplate which make it ajustable only by twisting the timing plate. I cant tune the left point to spark 3mm before top point.To be able to do that i need to twist the timing plate more but it has now been twisted to the maximum of what is posible. Now im thinking: how is that posible???
The bike runs but im not happy. It seems to me that it doesnt burn the fuel as it supose to do. There is a lot of unburned fuel in the pipes. Im starting to think that since the bike has hardly been used the carbs should have a inside cleaning.
User avatar
Alan H
Moto GP
Posts: 3160
Joined: Thu Feb 16, 2012 11:50 am
Country: England
Suzuki 2-Strokes: 4 x GT550s - J, M, A, B.
Location: The Republic of South Yorkshire

Re: tuning the timing gt380

Post by Alan H »

Sounds like your left points are done. The left points MUST be set first.
The trouble with rubbing points down with sandpaper or anything rough, is that it removes the hard faced plating on the points and they wear even quicker.
If the points are wearing or have a 'tit' on one side, the usual cause is the condenser needs to be replaced.
Think of how stupid the average person is, then realise that half of them are more stupid than that.
fastbike
Still in the Driveway
Posts: 7
Joined: Sun Mar 22, 2015 8:31 am
Country: norway
Suzuki 2-Strokes: gt380

Re: tuning the timing gt380

Post by fastbike »

I did the left point first according to the procedure.
Also, according to the maintenance procedure you ahould actually use a "point file" to clean the surface on the points. To use a sandpaper with the finess of 500 or 500 pluss will do the same trick.
By time the points get a pitting on one surface and a peek on the oposite surface and also oxidation. The pitting is ok but the oxidation and the peek needs to be removed by using a pointfile or sandpaper.
Changing points after 1500km doesnt make any sence.
User avatar
Alan H
Moto GP
Posts: 3160
Joined: Thu Feb 16, 2012 11:50 am
Country: England
Suzuki 2-Strokes: 4 x GT550s - J, M, A, B.
Location: The Republic of South Yorkshire

Re: tuning the timing gt380

Post by Alan H »

If your points have a tit on after 1500km, the condenser is on it's way out or is the wrong one.
Personally I would never file points as it just takes the hard coating off the points faces and is bad to get dead flat and parallel the faces so they make a good contact in any case.
Think of how stupid the average person is, then realise that half of them are more stupid than that.
fastbike
Still in the Driveway
Posts: 7
Joined: Sun Mar 22, 2015 8:31 am
Country: norway
Suzuki 2-Strokes: gt380

Re: tuning the timing gt380

Post by fastbike »

Hmm, is it normal that a condencer goes bad after 1500km?
Every thing is nippon denso.
The hard surface on the points get weardown anyway, right?
Post Reply