'82 GS300L Restore & Timing Adjustment - Complete Noob

[hjacobmiller]

Roger. Took it out and verified it was wrong. Spins correctly now and turns over. Doesn't want to start and starter still doesn't sound strong, and it seems like it really has to work to turn it over. Going to go to the other GS300 thread and see what others have set their carbs to. I don't think the fuel/air mixture is right, which doesn't explain the hard turning over, but maybe why I'm not getting anything.

I really appreciate all of the help.

Wish me luck!

 

[Guest]

Cool , glad you found the problem.


For slow cranking it could be starter still not perfectly aligned. That brush plate is a pain to get it set just right where it fits into the notches.

Or your battery is getting low.


For the carbs, they can be a pain but really they are not that complicated.

Cleaning everything that you can't see is the most important thing.

completely disassembling them and dunking the bodies usually does it.



When you were trying to roll on the throttle what does it do ? Did you have the airbox pushed on all the way?

These carbs will not work without the airbox and airfilter.

By design they need restriction. Even putting a rag over them will usually give some throttle response instead of just dying.




While you have them out and in your hands try this.


Push the throttle slide all the way up and block that long port on the back of the carb on the top.

Then let go of the slide and it won't fall down.

If you let your finger off the long port the slide will fall.

This is what the restriction in the airbox is doing in a way. Its making a slight vacuum in the airbox and pulling up on the slide.
There is more to it but that gives you an idea.


Also here is why it works on the choke.

Do the same thing. put the slide up , plug the port and then pull the choke. The slide will drop.


That's because the choke circuit also diverts some suction from the intake up to the top of the slide and sucks it up a bit.


By the way if the slide just falls down no matter what, you could have a busted diaphragm or the lip isn't in the right place under the cap.

 

[hjacobmiller]

Thank you so much! Unfortunately I think I am just going to have to take it to the shop tomorrow. I am going to call in a few minutes to see what sort of hourly service rate he charges and then go from there. I think I am doing more damage than I am anything else, and if I am close to getting it running it shouldn't be too much. Certainly less than what I would spend in replacing parts that I break along the way. This is the place I went for the unneeded r/r and they seemed to be trustworthy guys, especially since he tested my r/r and once it was fine didn't try to sell me the other one. Been in business for 25+ years and asked around and people say they're good. I think I definitely have learned a lot and hopefully when/if he gets it running I can do the minor things with help from the forum here.

I'll keep you posted though!

 

[hjacobmiller]

Update.

Riding! Finally! After a wiring harness swap and a new starter motor running as good as new. Well, almost. Went for a short ride down to the local beach and around the neighborhood and discovered a few things I need to adjust.

1. Clutch/Shifter - really hard to get into first and is touchy between gears

2. DEFINITELY need to adjust throttle cable and carbs. Too much play and it idles really high. I also think that this is causing the engine to run way too hot. It is really hot, to the point I can't even check the oil after letting it run for 10-15 minutes because the dipstick handle is hot. Could also be that the right exhaust is constricted and not letting it "breath" properly. Any suggestions on an inexpensive quiet aftermarket exhaust?

3. Front tire needs replaced. Slow leak.

4. I think I put the rear turn signals together wrong when I cleaned them. Easy fix. Also need to adjust the brake light switch.

5. Random bolts.

All in all with a few more hours of work this weekend I think I'll have a decent little commuter. Cleaning up nice, huh?

 

[Guest]

Download the Motovan catalog and choose a set of slip on pipes you like. 30-80 depending on the style you want. Any shop can get them.

Try and keep them the same length, shorter will cause a slight loss in top end power. I didn't go any shorter than the axle bolt. Mine are the slip on type and I can move them in and out for tuning.

Don't let it run for 15 minutes! There is no safe temperature limit while its sitting there and it can cook itself.

The dipstick will always be that hot.

These air-cooled engines need air passing over them otherwise they will overheat quicker than you think.

When you adjust the cable: Set the idle after a run and then turn all the way left and right to see which way the cable goes tight and loosen the cable until it idles normally and doesn't idle up with turning.

Where are your chrome valve cover caps?


looking good

 

[hjacobmiller]

Just hadn't put the covers on yet. Here it is after getting washed up and a little more shined up.

And here is the constricted header I'm talking about:

 

[Guest]

Oh Wow that is constricted. Keep an eye on the right spark plug, and try and keep it on the rich side until you get that fixed.

They are double walled tubes so it might be cinched more than it looks.

You might be able to use a gs400-450 exhaust header if you can't find the 300's

Looks good though.

 

[hjacobmiller]

Do you think that an ordinary muffler shop would be able to make a new header for it? I could look and see what the OEM# is for it and look around, but I wouldn't be overly concerned with it not being stock if a local shop could do something for relatively inexpensive that could just get a new set of headers back to where I could put some slip-ons on.

Still having a little difficulty with shifting back into neutral. Is there someway to make the neutral "spot" bigger? I know that there isn't really a neutral "spot" but what I guess I'm trying to ask is there any way to make it easier to find? I either over down-shift back into first, or I over "up-shift" into second. Tiny spot to find! I'm guess the clutch is still slightly off and could use a bit more adjustment (first is A LOT easier now) but any tips would be greatly appreciated.

Really need to get that tire fixed too. I think that the bead isn't set correctly because it has a high spot in it (uneven causing it to wobble). And this may be a dumb question, but can you put a tube in a tubeless tire? The tire is fine with good tread and no dry rot, but I could get it correctly mounted and put a tube in for cheap I'd prefer that to buying a whole new tire...

 

[Guest]

1 Ask Pete, He made his own from scratch and had a muffler shop do the rest. You could definitely get a shop to make a pipe that matches the bends and use the stock coupler off of your pipe although they might only be able to do single wall. you could easily have that section cut out and then weld inplace a pipe the same diameter as the inner one and slide another one on top of it to make it the same thickness as the stock one. After that its just cleanup work and paint.

On the neutral issue:

You see that bolt sticking up out of the top of the case just under the carbs on the right hand side behind the starter?

Take that bold off and you will find a spring and pin in there. Put something in there, like a small washers under the cap and it will increase the spring tension.

This is what locates the neutral spot.

Put it in neutral you will see the pin move as you shift. When you shift to neutral you are using this pin to assist you but you are also fighting the gear selector star. It wants to skip past neutral by design and lets you do that when shifting but its a pain to find neutral most of the time if the pin isn't helping you find it.

Adjust the tension until you can find neutral fine BUT keep in mind that you might find neutral when shifting from first to second if you go too tight. Try a few washers and then test. When you are in neutral you will see the pin all the way down, Any other gear and you will see the pin pop up. Don't install too many washers because you could cause the spring to bind up and get crushed.

Tire:
You need to inflate that tire quite a bit the first time to get the bead to seat correctly. After that it will be even all the way around and you can see the line just above the lip. It never seats properly when you only inflate it to riding pressure the first time. Not sure how high to push it but I lubed mine up and used a compressor and filled it until it was even all the way around on a new tire. Then I dropped the pressure to riding pressure.

Be careful though depending on the tire quality and age it could burst if you overdo it.


You can put a tube in it, Isn't it a tube already ? Usually the tube type has a valve stem with a nut that holds it in place.

 

[Guest]

Looks like I've been missing a twin thread! How slack! Thanks for the heads up Mekanix

I actually had my whole exhaust custom made though, the only bit I did myself was the cardboard mockup...

And yeah I agree, I'd definitely do something about that crimp!

I think the 250's and 300's may share the same exhausts too but I may be wrong on that one...

Nice little 300 you got there! She's cleaning up well

 

[hjacobmiller]

I tell you what, I am REALLY glad I found this site. You guys (Mekanix) probably aren't though, with me asking all my dumb questions! Ha! I was just looking back and the beginning of this thread and I knew nothing! Thanks for all of the patience and advice!

I went out for a ride tonight to put gas in it since I'd been riding just around the neighborhood with that iffy tire. Going to be rough to fill this up all summer! Ha! What a joke! $6.51 to fill her up! Got up to 50-55 and rode/shifted smooth as glass. What an awesome little bike!

Got my lights/horn all working now, tire has a new tube in it and is balanced correctly, got a cheap-o set of mirrors to pass inspection, threw the starter cover back on and let her rip. With the engine getting as hot as it doesn't the starter cover keep the starter from getting air and cooling off?

I definitely do need to get that header taken care of though. I'm wondering if I can pass state inspection with it how it is. I hope so, but I will try and find a place to make a new one ASAP. Should I do both the left and the right sides or just that ride side? I don't know if having a wider pipe on one side would cause running issues or not but I'm guessing you do!

I could probably do a better job of cleaning the carbs but for now I'll let sleeping dogs lie.

Again, thank you so much!

 

[Guest]

Yeah, noobs jk

I don't mind at all. Its like the first time I found this site with nearly the same bike(400) and similar issues. I still have the exact same bike. Its my second one of the exact same year, make, model and accessories.

The starter doesn't get cooled in any way and shouldn't ever get that hot while starting. Its used to the heat generated by the engine.


For now if you can get away with just doing the one spot. Cut just that part out of the exhaust and and measure the inner diameter and outer diameter to see what you need for the two pipes (inner and outer). Then find a place to get the two and make sure they can fit together and match that to the one you cut out. After that you can weld the new piece in place and grind it smooth again. Paint it and maybe paint the other one in the same spot to make it look symmetrical.


The carbs are a time consuming thing to do properly.

You have to disassemble them completely and dunk the body's only in carb cleaner. Anything rubber will dissolve or distort,.

Then after a time period of soaking ( what ever the cleaner says ) rinse the body's in hot soap and water. Spray carb cleaner through each passage again and again, let sit a minute and blow them out again with the cleaner and air.

Sometimes the dunking doesn't get into every little passage for the low jets or choke circuit.
Once they are clean and reassembled you can synchronize them by eye with a small drill bit under the butterfly valves.

Then you can set the float height if necessary.

With it running like that what are your spark plugs looking like ?

 

[hjacobmiller]

Anybody know what size the handlebars are? 7/8?

 

[Guest]

Anybody know what size the handlebars are? 7/8?

Yup... that's it.

 

[hjacobmiller]

Awesome! Thanks. I think I'm going to change the bars a little bit. All of the plastics have been painted and are drying now. Going to soak the carbs tomorrow night, install a new right side exhaust that I found on ebay for cheap and then hopefully put the carbs back on Friday and sync them up.

I had some trouble getting the screws out of the vacuum holes for the sync gauges. I don't think they'd ever been taken out... The phillip's slots got a little boogered up. Can I replace with other screws (hexhead, etc) or does it have to be a certain material? I noticed the washer looked like brass or copper, so I didn't know if those screws had to be something special or if just a steel one will do.... Was thinking of doing the same on the intake boots since they look rounded out too.

More pictures to come!

 

[Guest]

Get some stainless steel allen head bolts to replace them, don't round out so easily and look nice too. Don't forget anti seize!

The washers under the carb sync screws are actually gaskets to stop air leaks, so they're pretty important to be there and aren't just a generic washer either.

Now that you're talking about this, it reminds me that I meant to replace my carb sync screws with stainless allen heads... completely forgot about that!

 

[hjacobmiller]

Check! Got them replaced as well as the intake boot screws! Looks rather nice and is so much easier to work with.

Also replaced the whole ride side exhaust. There is no constricted header any more and the overall sound is a lot better, in my opinion.

I'm still not running well though. Here is the issue I have:

So it starts up fine with the choke pulled all the way out if it has been sitting for a while. Runs at higher than normal rpm (don't have a tach) and sounds great. After warming it up I push the choke in a go for a ride, no problems. It runs great and is really responsive and really quick.

However, other times it has NO power whatsoever and is completely unresponsive to the throttle. The exhaust doesn't sound like it is really breathing, and when I say that I mean there is no "pop" to it. You know that nice little edgy sound? Hard to describe, but I know it is definitely different from when it isn't acting up in this way. To me it sounds like it is not getting enough air. It takes forever to accelerate and just seems like I weigh 900 lbs and am trying to ride a Vespa. Struggles with hills, is sluggish after upshifts, and won't go above 35. Interestingly enough, the engine runs at the same RPM whether or not the choke is pulled all the way or or pushed all the way when it is acting up like this, but works fine when it is not acting up (higher rpm when choke is pulled out)

I just completely disassembled the carbs and dunked them in Berryman's for about two hours. Rinsed them with water, blew them out with air, and put everything back together so I don't believe there is any carb issue. I have the fuel mixture needles set to 1.5 turns out on each carb, per another 300 resto thread.

I'm thinking too tight of valves? I checked them when I checked the timing and loosened to spec, but maybe I was measuring in the wrong place? Where do I measure with the feeler gauges? I tried looking the BikeCliff manual, but the image is too blurry to determine where the feeler gauges are going in.

I also thought that maybe my fuel/air mixture could be too rich, or not lean enough. I don't know if that would cause this much loss in power, and I don't see any black smoke indicating excess fuel.

I also checked the carbs for sync. I put the gauges on after a good (not powerless) little ride, started it up and checked to see what the gauges pulled down too. Darm close to exactly the same on the both sides, so I must have gotten pretty close after reassembling the carbs.

Just a thought, but possible too much oil?

I'd appreciate any advice on where I should go first (valve clearance, fuel mixture, new bike - just kidding, etc.).

It's looking good and I'll throw up some pics when I can ride it down the beach so the attention is drawn away from dirty valve cover and cylinder head fins.. How do people get those shiny? :O

 

[Guest]

Between all 8 valve stems with the lobes facing straight up on the one your measuring.

2 hours for a dunk isn't enough. Try 24 hours and then rinse with water and then clear all passages with carb cleaner and then air.



Sounds like its running out of fuel by the way your describing it or maybe running on only one cylinder.

If you take a 500ml pepsi bottle and cut it at a slant you can use that to catch gas coming out of the bottom of the carbs. Next time it acts up try pulling the plugs and see what's in there. I'm thinking one is going to be almost empty.

The choke bypasses everything and has its own pickup. Only way the choke doesn't work is when there is no fuel left to pickup or the tube is plugged.

I'd check to see if its getting fuel when that happens by switching to prime and opening the gas cap to make sure its not a vacuum forming in the tank.

Too much oil and you would hear the pistons slapping as they slosh the oil around. Its quite noticeable at low rpm but it wouldn't cause the power loss.


The connections to the coils are not that good and sometimes cause intermittent faults. So you could be running on one cylinder intermittently but I doubt that's it.

I think your running on one carb of fuel though. As if one was draining and not filling as fast or at all.

To shine the fins its going to take time and patience with a dremel and coper or stainless brush tip. It takes a long time to do it all. There are other ways but it involves removing the head and having it coke blasted.

Pete did that with his and it really makes it look good.

 

[hjacobmiller]

OK, well I just pulled the carbs off and put them in cleaner in to soak over night. Do you think if I let them (carbs) soak undisturbed for about 18+ hours that will be long enough? I separated them both and removed all rubber, took all the jets out, etc. so hopefully after rinsing them and blowing them out again I'll know for sure that they are clean and that isn't the issue.

Side note, when I pulled the carbs off, I loosened the drain screw in the float bowl and each carb bowl had gas in it that I drained off. I'm not sure if that is what you're referring to, but I also smelled both spark plugs and they definitely had fuel on them both. But you're saying to take a flash light and look down in the cylinder to see if there is gas?

I also decided that I am going to recheck valve clearance tomorrow. And do a better job and know 100% that those are not the issue either. I'll double check the timing to make sure that isn't it either. I loosened the valve cover and took the spark plugs out, put some paper towels in the holes, and looked at the spark plugs, especially the right one because of that old crimped header. Both looked fine, although I'm not sure the gap was set right. Will double check that as well.

Is there any way that I can check and see if both cylinders are getting sparks? Oh, a way that doesn't involve me getting shocked would be preferable ha ha.

When putting the exhaust back on, was there anything I could have messed up there? Overtighten, under tighten? I seemed to be getting the same amount of pressure from the mufflers when it was running, so I'm assuming that both cylinders were firing, although I suppose the pressure building up as the crank turns could cause exhaust pressure as well.

Well, after I get everything back together tomorrow hopefully it will run better. When it runs great it is a blast, especially after putting drag bars on it. It is really looking nice, and I definitely owe some pics after all of this advice.

 

[Guest]

After that I'd say they are perfectly clean.

Did you dip the bowls? The tube for the choke goes into the bowl and that part can be plugged up too because there is a small restriction jet in there.

There would be gas in the bowls from it sitting for a bit. I meant that when it was acting up that if you check then there would probably be more gas in one than the other if its a fuel problem.

To check spark just put the plugs back in the caps and lay them on the head. Keep them away from the plug holes and crank it over. You will see spark quite easily and if there was gas shooting up from the plug hole (as if it was really flooded) then it would ignite if the plug was right over the hole.
But its really easy to check for spark. Yellow is weak. Blue is good but the real test is with a spark gap tester where you can change the gap and see how far it jumps. That tells you the voltage its outputting.


Nothing you could have done by putting the exhaust on. You might have tight valves or a burn exhaust valve but that's the last thing to look at.

The rockers amplify the lift of the camshaft by 1.53. If you measure the valve clearance between the valves and rocker you are getting the right gap. If you measure the rocker to cam gap its going to be 1.53 times tighter I would think. OR if you set the gap by the cam and rocker its going to be 1.53 times too loose at the valve.


With mine which is almost identical except for 100 more cc's Ive noticed there are only two things that cause it to loose power.

That's running low on fuel in one or more carbs or bad ignition or connections on one side.

Its obvious when its running on one cylinder though. Could be just a bad plug or plug cap.

Flooding and lack of gas gives the same lack of power feeling.



Yes more pics