380j Timing Issue's... I think?

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getLICKED
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380j Timing Issue's... I think?

Post by getLICKED »

Hey hows it going all? This is my first post, so I'll be polite and introduce myself... My name is Jesse, I'm from southern Maine, And of course, I love working on motorcycles! I'm a huge fan motorcycle forums, and glad I can now be a part of this one.
The list of bikes as of now goes
1. 81 HD Wide-Glide STROKER!
2. 84 HD flhs stock and sexy
3. 73 AMF/HD TX-125 on/off rd.
4. 74 KAW H1
5. 89 RZ 350 flattrack'd
6. Last but not least, this little gem......My pops found this in some lady's mud room, sitting there covered in oil(which I am so thankful for!!!). We grabbed the truck and went back to the house it was at, and dragged it outta there. tires flat, and rear brake seized trying to fit it though this woman's front door every which way we could, at the same time trying not to let her 3 cats out, who were attempting to bolt every chance they could... one succeeded. We ending up dragging it through the house and out the back door, and into the truck it went. The lady was so happy to have it out of her house, she refused to except a dime... so I helped her chase down her cat that got away, and the deal was done.

All three piston's were seized, carbs a little dirty, but for the most part, it was all in pretty good shape considering the last time it was registered was 1983. I pulled the head, and put the mystery oil to the pistons for a few weeks, and occasionally stuck the torch to the jugs in hopes that it would allow the cylinders and pistons to move around, making way for the oil to seep in. An after a month, I managed to get the jugs off. I was hoping to get away with only having to hone them, but they were in need of a bore 0.05 over. which they got, and cleaned up nicely. Ordered a set of pistons/rings an a gasket kit. Then stuck it back together carefully following the torque specs. All 3 cylinders are now at 118-120 psi

I disassembled the carbs, and cleaned them up as best I could. The main, and pilot jets are free of debris, the bowls are clean, and the float valve is working fine, same with needle and slide. Is there anything i'm missing??? (would anyone happen to know the recommended/stock settings for these carbs?) I also scrapped the air box, and replaced it with pod filters.

The gas tank has a massive amount of rust sloshing around in it so i decide to take it off and deal with that later. For the time being I rig up a temporary fuel bottle with an inline filter, and all new fuel line. This setup does not have a vent...

So with the new top-end, new plugs, a new battery(fully charged), macgyver'd fuel tank and the cleaned/synced up carbs I attempt to fire it up. First I check the ignition-check, next I make sure there's fresh oil in the lines-check, measured proper piston/head clearance-check, pull out the manual and make sure that the points L, C, R, are all gaped correctly, and that the timing plate is not retarded nor is it advanced-check. then I check all three plugs to make sure there's a healthy spark-check, I wasn't sure about what had been living in the pipes, so I take them off, and blow them out with comp. air-check, last but not least I pour myself a tall ice cold beer and put it on standby. This last check is key! -check.

Finally! turn the key, pull the choke, twist the throttle a few and start kicking..... 3-4 kicks or so, and im just waiting for it to kick back and fire up, leaving my garage in a cloud of half-burnt oil...ahhhhhh that wonderful scent.. but nothing..... Shut the choke off, and give it a minute to make sure its not flooded and try again.. nothing....10 more kicks...nothing.......I drank the beer anyways...

It's as if there's no spark at all.. almost feels like there's not that much comp. either, but I've checked it again and its there. could it be the pod filters I put on it? maybe the intake is open too much, messing with the air/fuel ratio. I have not re-jet'd since the pods, but even if it was the jetting, it would at least fire and run lean, right?? there'd be some signs of fuel being ignited like a little puff of smoke. I got nothing. I've double checked most things, even triple checked. The one thing I am not certain about is the points/timing plate. The manual say's that it should be taken in to a dealer to get done, but it also notes that if you need to get done in a pinch and get it to ballpark setting, follow these instructions. Which i did. and it wasn't too far off to begin with. I'll search around here on the forums, and find specifics on eh timing issue, I have a feeling that it is...

Your thought's??? Anything i'm forgetting? yes the kill switch is set to on....
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Craig380
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Re: 380j Timing Issue's... I think?

Post by Craig380 »

Hi Jesse, and welcome, that looks like a good 'mud room' find.

The problem with checking the timing by the method in the factory owner's manual is .... the owner's manual is completely WRONG :? :shock: what's worse is, Suzuki never corrected it :roll:

The manual advises you that the points cam turns CLOCKWISE, it's actually geared off the crank so turns ANTI-clockwise as you look at it. Also, it's a really bad idea to turn the points cam using that inviting-looking nut on the end of it. The point cam is driven by a nylon gear off the crank, which can get cracked and broken.

So if you set the timing using the method in the owner's manual, it will be a LONG way out of whack ... luckily, this is one of the few eccentric features of the 380.

I'd suggest checking the timing again, but this time, use the kickstarter to turn the engine over gently. This ensures the whole engine is turning the correct way, and you can then get it set to the timing marks. Those are good enough for an initial fire-up.

Also, I can't remember if the early 380s had a vacuum fuel tap. If they did, there will be a vac hose take-off on one of the carbs. If you don't block this off, it will be sucking air and making the mixture lean.

Good luck, you've done the hard work, keep us posted!
1976 GT380 - wounded by me, and sold on
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Re: 380j Timing Issue's... I think?

Post by jabcb »

Some people on the forum put the bike in 6th gear & use their foot to turn the real wheel.
That's what Suzuki recommended in a service bulletin:
http://www.ozebook.com/compendium/techb ... 0mc119.pdf

All GT380s have the vacuum petcock that Craig380 mentioned.
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Re: 380j Timing Issue's... I think?

Post by TLRam1 »

And pod filters are generally a bad thing, they will work better if you extend the length of your venturi tubes. If you have turned that nut referred to above chances are it has broken the nylon gear and your timing is way off.

Make sure you have injector oil in it.

If the carbs are flowing as they should, timing set properly, compression good, it will run.
Terry

Maybe poker's not your game, Ike. I know! Let's have a spelling contest~

74 Suzuki GT750 / 74 Suzuki T500 / 75 Suzuki GT380 / 97 & 01 Honda Magna / 03 Kawasaki KX250 / 01 Yamaha WR250F / 03 Yamaha TTR 125L
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Re: 380j Timing Issue's... I think?

Post by getLICKED »

I found the manual to be a bit confusing to begin with, so I searched online, read a bunch of threads, and gathered up all the information regarding the 380j's timing.. the only difference is the manual saying to turn the cam nut, which i did not do. I've read about the nylon gear on here when the top end was being done, just to kinda plan my next step, thankfully it saved me a plastic gear!

First set the fixed L point gap to 0.014", then repeat for other points..

Second depress kick start to line the L timing mark up with the casting mark, rotate plate until the fixed L points have split, resulting in 10.04v between the 2. rotate 360 back to the timing mark once again, double checking that the points split precisely on that mark.

Third repeat process for other non-fixed points, adjust them using their corresponding timing marks and their own plates.

I had an issue with the R points, they weren't closing all the way... it would constantly have a 10.04 charge, even when the fiber lifter wasn't touching the cam. so i pull it off and use a piece of 600 wet or dry, and just barely kiss it, making sure I don't round off the corner or remove any tungsten. This solved my problem.

One thing I've noticed, is that there's an audible arc flash on the L points, which makes me believe the condenser may be faulty. But there's still a good healthy spark ??????

I would assume, If that nylon timing gear is indeed broken, my timing adjustments would for sure be all over the place after 10 attempts at starting, which they are not. they are still as I set them. would the cam even rotate if it were broke?

I've read about using a dial indicator to set the timing. I find this method to be more mechanically accurate. The guy that owned this bike before me, could have taken it apart, and put it back together not following the detailed instructions. leaving me reference-less with the timing system. I'll hunt down a dial indicator and see how far off it was. 3.37BTDC right???
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Re: 380j Timing Issue's... I think?

Post by Craig380 »

Think the timing gear's still fine, if you're turning it slowly it won't break too easily. If it's turning the point cam it's probably fine.

3.37mm BTDC is for the GT550, if I remember right the 380J is about 2.7mm BTDC.
1976 GT380 - wounded by me, and sold on
2006 SV650S - killed by a patch of diesel and a kerb in Feb 2019
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Re: 380j Timing Issue's... I think?

Post by Coyote »

Look at the first sticky in this section All the info you need is there. That's why I posted it 8)
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Re: 380j Timing Issue's... I think?

Post by Coyote »

Are the plugs wet? It sounds like it's not getting any fuel. Go to the auto parts store and get a can of starter fluid. Give each cylinder a healthy squirt with the slides raised. If it doesn't fire on that, something is radically wrong.
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Re: 380j Timing Issue's... I think?

Post by getLICKED »

Ether?????? My dad says I can't play with that anymore.... :twisted:
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Re: 380j Timing Issue's... I think?

Post by getLICKED »

Well, I tried using some starting fluid, pulled the air filters and gave it a dose.. starting off with little dose's then working up to bigger dose's with the slides open. And nothing happends.....
I did hear one little crack from the center cylinder, along with an unfamiliar smell.. seems odd.

I pulled the carbs off, and looked into the jugs to see if maybe i had left the rag in the intake from after the machine shop, and its all clear.

One thing i did notice though, is when the piston is on its way down, it never comes down far enough to expose an opening between the intake port to the cylinder... I've grown up tinkering with 2-strokes, but to me, that seems a little strange. Does the air/fuel mixture travel under the piston, and up through the transfer?
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Re: 380j Timing Issue's... I think?

Post by Coyote »

Does the air/fuel mixture travel under the piston, and up through the transfer?
I believe that's exactly how it works. If you have a Clymer manual, look on page 23.
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Re: 380j Timing Issue's... I think?

Post by Buffalo-guy »

On your start-up description, you mentioned choke on, and twist the throttle. The choke only works with the throttle fully closed. It is not really a choke, but an enrichening circuit, that requires high vacuum (closed throttle) to work. Maybe a leakdown test to find out how the crank seals are, may be in the future as well. Are you getting a nice strong spark on the plug when properly hooked up and grounded? Simple stuff first, then throw money at it. Sounds like you aren't out too much yet. Good luck.
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Re: 380j Timing Issue's... I think?

Post by getLICKED »

Buffalo-guy, just did a leak down, and all is good, it held strong for a solid 10 min... also the spark is strong.

FOUND MY ISSUE!!!

After the leak down, I was fed up. Just listening to the bike trying to start, i knew it had something to do with the timing. Because with fuel, spark, and compression, there should be at least a slight sign of firing...

Tracked down a dial indicator, and set it up on the left cyl. rotated engine until it hit TDC and zero'd it out. cycled it around once more to be sure.
Then using the cam nut carefully reversed back about 5mm, then back up to 2.7(0.106") and sure enough, the R propeller mark was in sight....
to make sure I didn't have the orientation of the cylinders wrong, I stick the right side spark plug in, ground it and flick the right side points and it sparked the right side.

So... something in there is backwards....

I replace the spark plug in the left cylinder and throw the right side coil on it. moved to the Right side cylinder and repeated the dial indication process. The center timing mark shows up in the timing plate window, replace the right spark plug and put the center coil on it. then replaced the center spark plug and put the left coil on it. kicked it ONE time and it fired..... it didnt idle but it fired....

I'm guessing that the timing gear is off, and needs to be adjusted. surprisingly enough, the timing set without a dial indicator is dead on(2.7mm)... just on the wrong cylinder...
I'll pull the clutch cover off right now, and pull the timing plate, then check back here in about 45 or so, to see if anyone posted on how to readjust this thing.
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