Suzuki 2 Strokes

Hey guys,
I have a 72 GT380. I'm having real trouble with the pointS. Thanks to this forum, I do understand how to set them. The problem is that there is no way I can get the left set (or any other) to open at 2.99mm btdc. The best I can do is about twice that. The plate has been heavily modified. Some one in the past has WAY extended the slots. My question is: Would the breaker cam being really worn out cause this condition? Adjusting it barely makes any difference even with the modified slots. I have taken the clutch cover off to make sure that the dot and arrow were aligned and they are. (Didn't break the nylon gear thanks to you guys!!) And when the arrow and dot are aligned the left piston is where it's supposed to be on the dial gauge. This bike has over 45k on it!! I know that the heels are worn out and the new points are on the way but I just wonder if the cam could be worn out with that kind of mileage. Any help or advice would be very much appreciated!!!!

Hi there, the cam should not wear THAT much, it only has a gentle profile compared with a car distributor.

See how you get on with the new sets of points. Sometimes you have to compromise the point gap to get the timing aligned. The point gap can be between 12 and 16 thou (0.3 to 0.4mm), it's a good idea to set it slightly on the wide side when fitting new points as the heel will wear quickly to start with as it settles in.

Keep us posted.

+1 If the heels are worn out,you'll never get there. Is the cam nice and smooth? If it's pitted, it will wear the new heels out very quickly and you will be faced with adjusting the timing all the time.
It's good to know when the arrow and notch line up when the piston is in the right place. That way you can just use those marks to time the bike.. On this last bike, I used a dial indicator to do the test to see how close the marks were. All the marks were spot on so I put the indicator away and timed to the marks. Suzuki says those marks are for emergency purposes only, but I have always found them to be very close or spot on.
When you're all done, fire it up and use an automotive timing light to see that all plugs are firing on the marks.
Keep your eyes peeled on eBay for a new cam. They show up from time to time.

If I understand you to say that the points open too early at around 7mmm BTDC, trhen it sounds to me like the side cover was fitted one tooth out from where it should be. or maybe even 2 teeth out.

Thanks for the advice guys. Its really is awesome that there is a place where people with real experience can share with newcomers. I'll make sure to pay it forward!!! I found the cam and ordered it. Hopefully the cam and points will be here by this weekend. As far as it being a tooth or two off, I had the same suspicion. I check it with the dial guage and with the dot and arrow aligned it was spot but wasn't opening near the right time. Just for logics sake I then advanced it a tooth and got closer then I advanced it another and got close enough that I think it would run if I kicked it. I still didn't have much adjustment with the plate. I just rebuilt the top end on it and didn't want to hole a piston so I lined the dot back up and put the case back on. Im hopeful that I won't have to pull that cover for a long time. We'll see!!!

I tend to agree with tz375 as I had exactly the same problem on my 380. I did the same as you have done. With the clutch casing off I aligned the arrow to the dot on the crank gear and left piston was in the correct position BTDC. I aligned the propeller blade marked L in the clutch casing to the casing mark and replaced the casing and tightened everything up. Then I tried to time it up which is when it all went wrong. I too found I could not turn the back plate enough to get the points to just start opening in the correct position. After a lot of head scratching I discovered the nylon points gear had moved a tooth out when I replaced the casing. You did not say if when the left piston is at the correct BTDC your L mark on the propeller is lined up with casing mark.
I have a GT380 B with 30,000 miles on the clock and my points cam is fine, so I can't imagine yours being so badly worn.

Easy solution. If the plate's slots have been modified. Buy a new one. There's used ones all over ebay for very little money. Clean it up and spray paint it silver metallic. Just communicate with a would be seller that all threads are not stripped. It's common that the phillip screw holes have been stripped at one time. Due to over tightening of the screws that hold the points in position. Even so, you can rethread them if needed.

Yes, the L lines up with the cast timing mark on the clutch cover when the arrow and dot are aligned. I wouldn't expect the l breaker cam to be worn to any serious degree either but I only have 2 variables now. The points themselves and the breaker cam. I found the cam for 20 bucks (and also made a new friend with a cache of nos 70s parts). Mine is a bit ugly and slightly pitted. I figure it's worth 20 just to have another variable out of the equation. I'm going to keep this bike for a good long time. Top end is fresh as a daisy and the crank was rebuilt in 2002. It did sit for 2 years before I got it. A bit worried about the crank seals but I'll cross that bridge if I have to!! A buddy of mine mentioned a seal rejuvinator called "Blue Devil". Says he's used it in snowmobile engines with about a 50% success rate. Anyone here ever heard of it?

Robiet wrote:Yes, the L lines up with the cast timing mark on the clutch cover when the arrow and dot are aligned. I wouldn't expect the l breaker cam to be worn to any serious degree either but I only have 2 variables now. The points themselves and the breaker cam. I found the cam for 20 bucks (and also made a new friend with a cache of nos 70s parts). Mine is a bit ugly and slightly pitted. I figure it's worth 20 just to have another variable out of the equation. I'm going to keep this bike for a good long time. Top end is fresh as a daisy and the crank was rebuilt in 2002. It did sit for 2 years before I got it. A bit worried about the crank seals but I'll cross that bridge if I have to!! A buddy of mine mentioned a seal rejuvinator called "Blue Devil". Says he's used it in snowmobile engines with about a 50% success rate. Anyone here ever heard of it?

Never heard of it. But, I'm sure that it works like any other seal rejuvenator. Sometimes those work, most often not. The problem with seals is they begin to crack or split. No rejuvenator is going to fix that. Swelling or hardening, perhaps. When my seals went, it cracked off into pieces. One piece was found in my spark plug electrode when I began to see problems. I believe, a good prevention in allowing crank seals to last a long time is keeping the bike from sitting in cold temperatures.

I'll know about the seals soon enough I suppose. Until then I'll keep my fingers crossed.

I wouldn't get overly uptight about the seals. I bought a buffalo that sat in a chicken coup untouched for 25 years. Seals were fine.. It's probably this imitation gasoline that's killing them now days. Search your area for non ethanol gasoline and use it.

380's can have a Denso ignition or a Kokusan and the points are not interchangable. Cams are different as well.

Barry makes a good point (no pun intended ) about Denso and Kokusan ignitions. Bikes with Denso ignitions have the condensers laying side-on on the points plate, I'm pretty sure the Kokusan ignitions have the condensers sitting end-on.

And +1 to what Coyote said about the crank seals. I know a guy in the UK who is a serial buyer and restorer of 380s - he's had over 20 pass through his garage. He once told me that unless something was actually broken in the engine and had physically damaged the crank, bearings, rods or seals, he's never had to rebuild a crank and has never had a problem with worn / dried seals, even with bikes pulled out of years of dead storage.

Mine are kokusan. Still not here yet. Just been doing some cleaning and polishing in the meantime.

This is my current set. I'm pretty sure that the worn heels are causing my issue. The cam will be here today but the points haven't even shipped yet!!