Hey - I'm new to the forums, and hoping someone here might be able to help with a couple of questions I've run into.
I got an Ace from a neighbor about 10 years ago, who had let it sit for 10-15 years. I had it running within about a week of getting it, and then I 'restored' it on a budget in high school. Unfortunately I wasn't able to get a title for it, so it was stored again. Two years ago I took it apart to get it going again, but things took a turn and it had to sit again - this time in boxes.
A month ago, I got it out of the boxes, and put it all back together.
I took apart the carb and let it soak in solvent for about a week, and then put it back together with a rebuild kit - new jets, gaskets, etc.
I've been having a hell of a time getting it to run since then. Now I've got it running, and it runs nice and strong at 1/4 - full throttle, but it just won't idle. I'm not sure where to initially set the throttle slide adjuster, and I can't get it idling enough to see if the pilot screw is having any effect.
Just kicking it over, without giving it any throttle, it seems like it gets loaded up. If I open the choke it will fire after a couple of kicks, and then take some revving to get it cleared out. If I open the throttle slide adjuster a little bit, it will fire again, bog at first, and then run as if its on 1/4 throttle with no load. (high RPM, not quite racing)
I started with the pilot screw 1 1/4 turns out, I've turned it out as far as 3, and in as far as 1/2 but it hasn't seemed to make much difference. If I get it started and just keep lightly revving it, it will stay running, but if I am rolling at low speed in gear, it will stop running until I give the throttle a little twist and it will kick right back to life.
I think the top end is OK, but where should the gearing run out - 1st gear seems to die off around 16-18mph, 2nd gear around 25-28 - where are the normal red lines? Will a 4stroke car tach work on the bike for diagnostic purposes?
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Forum Admin - 05/17/09 at 8:53pm
Mark it sounds like your pilot jet is either blocked or the choke circuit is blocked. Take the pilot jet out and be sure it is clear by holding it up to the light. If it is clear then there is blockage in the pilot jet circuit. You will need to clear the passage under the pilot screw via carb cleaner and air or maybe just carb cleaner. I assume the bike will only idle with the choke on ?
The air screw should be kept at between 1 1/4 turns to 1 1/2 turns open.
The slide screw you describe is the idle adjustment. You just most likely have a slight blockage in the pilot circuit. Let us know what you find please.
Paul
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Bullfrog - 05/17/09 at 9:03pm
Sounds like classic symptoms of a plugged pilot jet or pilot circuit passage. The pilot circuit is the primary provider of proper mixture at 0 to about 1/4 throttle - and proper operation of the pilot circuit is required for easy starting and dependable idle.
So I would recommend that you remove and disassemble the carb and clean it again. This time, pay special attention to the pilot jet AND ALL the pilot circuit passages. Use a squirt can of carb cleaner to assure that all passages are clear (wear eye protection, you may get squirts from some surprising places).
Do you have an in-line fuel filter? Be sure to install one to help prevent recontaminating the carb.
Ed
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Mark Potter - 05/17/09 at 9:09pm
I am guessing it is the pilot circuit, because the choke circuit seems to be working right. If I turn the choke on, kick it a couple of times, then turn it back off, give a little twist on the throttle - say 1/8, it will fire up, run fast, then sound like it bogs down and dies. When it runs like that if I rev it a little bit, it will run, and run well at middle rpms, but bogs at low rpm.
It does smell rich during this, which leads me to think it's the air half of the pilot circuit. Is the screw on the 100 air adjustment only? When you say air - do you mean just some directed compressed air? Does it help to back the pilot screw out quite a bit while trying this?
I'm gonna run across the street to grab some gas to thin down my 20:1 to 32:1 or so, after seeing some other posts about the modern premix, so I'll grab some carb cleaner at the same time and see what happens.
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Bullfrog - 05/17/09 at 9:41pm
Mark:
It isn't your fuel mix.
You have a plugged pilot circuit. The "pilot screw" you referred to in your first message is acutally the "pilot air screw". It is called the pilot air screw because it is used to "meter" the amount of air that is introduced into the pilot circuit. Turning the screw "in" progressively shuts down the amount of air running through the pilot circuit, resulting in a richer mixture. Turning the screw out allows progressively more air into the pilot circuit, leaning the mixture. Since there is no change from turned all the way "in" to 3 turns "out" - it is apparent that the pilot circuit is NOT working as intended.
Either the pilot air passage is plugged (which would explain why tuning the pilot air screw does nothing) or the fuel portion of the pilot circuit is plugged (if the pilot jet can't deliver fuel, it won't matter what setting the pilot air screw has been set at). OR both are plugged.
Take a deep breath . . . and accept that you must remove the carb and clean it as described. (That guy Paul knows what he is talking about. Wink )
Ed
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Mark Potter - 05/17/09 at 10:09pm
Ed - I didn't think it was the fuel mix, that was more an unrelated side comment - I wanted to dilute down from 20:1 to more like 30:1 to bring the smoke level down a bit.
I shot some carb cleaner into the air passage, with the pilot air screw out, it comes out the hole, with it in (backed off 3 turns), it seems to be getting past the screw, because not as much comes back out the air passage as is going in. With it 3 turns out, I started it and rode it, but it definitely was worse at low rpm\throttle (dying easier when coming to a stop \ slow speed, harder to get going again), and seemingly the same at mid-high rpm\throttle. It's dark at this point so I'm going to give the neighbors a rest, but tomorrow I will set it back down to 1 1/2 turns and see how it runs.
Where should I have the idle adjustment set while I'm doing this? Is there an internal height measurement that is ballpark close?
If it still won't idle tomorrow I'll pull the carb and go through it again. Will definitely wear the goggles - learned that lesson the hard way when I was working on this thing in '98.
Many thanks for the input so far.
Any input on the gear ratios, road speed, and engine speed? It's got the stock sprocket sizes, with 36t at the rear, and 15t counter.
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Forum Admin - 05/18/09 at 6:31am
Good morning Mark,
You are in great hands with Ed's advise !
If I can suggest making one change at a time. Take Ed's advise and go slow if so this should be easy to fix.
The air screw at 1 1/4 to 1 1/2 turns from closed is where you want that screw to be for your stock bike so I might suggest just leaving it there and making adjustments around that.
Anymore than 3 turns and you are wasting your time as it will not open any larger.
There is not a specific spot for your idle adjustment screw. You want to be sure the slide is seated down at the bottom of the carb first. Then you can make your idle adjustment which lifts the slide . Start at the bottom and work your way up.
I stand by the first thought I have and Ed has that it is in your pilot circuit or your pilot jet. Was your pilot jet blocked ? What number is stamped on your pilot jet ?
You have an Ace 100 is your idle adjustment screw on the side of the carb or the top ?
Thanks for your posts
Paul
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Mark Potter - 05/18/09 at 9:03am
Paul - I appreciate the advice. I will try to narrow things down to changing one thing at a time until I get this figured out.
I will post pictures of my carb this evening, but I'll do my best to describe it here as well.
The idle adjustment screw is at the top of the slide, next to the throttle cable. The only other external adjustment is the pilot air screw, towards the front right of the carburetor.
Looking in the opening of the carb, there are two passageway entrances at the bottom - the pilot on the right, the air jet in the center. The passage for the choke is up on the left wall, vs another passageway in the bottom.
From my Clymer book, it seems like that should narrow down which carb it is, but it doesn't have the detail on this particular carb as it does on the ace 90, and 100b carbs, which both seem to be different.
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Forum Admin - 05/18/09 at 10:09am
Why I asked you Mark where your idle adjuster was is that things get changed over time with the bikes and parts. I had a thought ( scary huh?) that you may have had the wrong carb. I just wanted to be sure that we are all on the same page.
Mr. Floyd Clymer did a great service with his manuals but be careful there is sometimes more dis-information than information.
The illustrated parts drawing of the Hodaka carb below is of an Ace 90 20 mm Mikuni carb. Yours is a 22 mm carb. Both are almost identical except the bore.
Thanks.
Done for now with the internet as the computer is getting unplugged. Check back in a few days when I get to Vermont.
Paul
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hodakaronwa - 05/18/09 at 4:19pm
Look the excellent parts break down over very carefully.
It sounds like you did not disassemble your carburetor all the way. I believe you missed what is called the "pilot jet" or idle jet.
It would be found in the small orifice beside the main jet. It will take a small screwdriver to get it loose so it will fall out. NOW! even after the pilot jet has been removed you should be able to hold the carb body up to the light and see light through the orifice. You need to do the same with the small pilot jet, normally just carb cleaner will not unplug a pilot jet, you will have to use a small wire. Then follow up with the cleaner and follow that with compressed air. after you remove the main jet, you will want to remove the needle jet which pushes out up through the venturi. This must be cleaned inside and out also followed by compressed air. every orifice must be flushed with cleaner and compressed air. You cannot clean a carb from the outside, you must get into it "literally" The worst thing for a carburetor is to store it with fuel still in it? Run it dry or remove it and drain it prior to storing for 5 months or more. Yamaha makes a great carb cleaner. The best.... and an ultrasonic cleaner is a great way to to make a complete job of it. If you have corrosion from water in the carb use lime away or mild murratic acid diluted with water. Always follow up with compressed air blown through every passage in both directions with all components removed from the carburetor body.
NOTE: Even with all the care in the world used to clean a carburetor for vintage machines, sometimes you just cannot save them from the ravage of time and the elements.
GOOD LUCK
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Mark Potter - 05/18/09 at 10:02pm
The first time I had the bike running (in '98) I didn't do a full disassemble of the carb - just pulled it, pulled the bowl off, blasted it with carb cleaner, put it back together and then did a Minnesota tune-up (strong mix of sea foam).
This time I did pull it, and completely disassemble it, and let it soak in mineral spirits for a couple of weeks, including the pilot jet. I did re-use the old pilot jet and I do think it is plugged. I assume I should be able to see through the jet end to end? I can see through the orifice it came out of, and a quick shot of carb cleaner finds its way through the rest of the passages.
I cleaned the pilot jet until I could see through it end to end, re-assembled, put it back on the bike, turned on the fuel, no choke, by the middle of the first kick it started right up and idled perfectly.
That's the Hodie I remember!!
Many thanks to everyone that helped me out on this, you guys are rock stars.
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Mark Potter - 05/19/09 at 10:25pm
So - things aren't quite as right as I would like.
The idle side of things seems to be right, however the bike isn't making as much power as it should be, and the top end is definitely lacking. It seems to be bogging at 1/4-3/4 throttle and until it gets wound out. On flat ground you have to really wind out second and third gear to get anything in the next gear, and fourth you can only cruise in for a little bit before dropping down to third and winding it out again. Hills are second and third gear affairs only.
I've tried both one notch lower (richer and worse) and one higher (leaner) than the middle notch on the needle, with the leaner setting running considerably better. If I have to go to the top rung \ leanest setting of the needle valve is it likely that the main jet is wrong, or is it somewhat normal to be using that setting?
It's not four-stroking or doing other obvious things to indicate its rich, and I don't want to run it lean inadvertently for any length of time. I assume its as bad for two-strokes as it is on anything else..
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sachs175 - 05/20/09 at 12:19 pm
I would do a full tune up including a compression check and exhaust pipe/ baffle clean out.
If the bike ran better from 1/4 throttle and up before you got the pilot circuit working......... then a recheck on every thing touched would be in order.
Hope this helps ,
John D.
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hodakaronwa - 05/20/09 at 10:49am
What does your air filter look like?
Is your ignition timing spot on?
Do you have a clean fuel tank,fresh gas, and a good fuel filter?
Are you positive that you did not miss something during your carburetor cleaning?
Did you actually remove and clean the needle jet?
Did you verify your float level?
How is your spark plug? Often during tuning you will have a spark plug go bad for one reason or another. People will just keep trying to fix a problem and they may have fixed it but during the coarse of curing the problem they have killed the brand new spark plug which they just bought.
It pays to have a few new spark plugs around.
If your problem persists it might be wise for you to send it to one of the many specialists which participate in this forum. Ultrasonic cleaning is the most thorough and complete method of eliminating all
possibilities of obstruction problems. Followed by boiling in Yamaha carb cleaner. This is what we do with all the hundreds of carburetors which we clean during the summer months which have been stored for extended periods.
And I will add this...just because you can visually see through your jets, this does not verify that your jets are open to the precise calibration which they were factory produced for. It is sometimes better to replace them, especially the pilot jet.
The needle jet is where I would look also, like I suggested previously.
The needle jet can have obstructions as it is a bit more complicated than you might think at first.
The pilot jet has very small holes around it's exterior and they must be open also.
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Mark Potter - 05/20/09 at 10:18pm
Air filter - NOS K&N unit
Timing - I will check tonight - is using the case markings, flywheel marking, and a feeler gauge close enough, or do I have to get a timing light?
Fuel tank - previously kreem'd back in the day, fresh fuel, brand new good fuel filter - fuel flow doesn't seem to be an issue.
Carb - I have checked and now re-checked. The only thing I missed was the pilot jet end to end. It's as good as its going to get without replacing. Every other piece that wasn't part of the carb body came off during cleaning and are in good shape. I've shot carb cleaner through every orifice I can find and it appears to be unobstructed.
The needle jet is definitely good and clean. Verified the outer air jet ring is good and clean with no obstruction, and the air jet itself appears to be good.
Float level was verified with gasket out - 7/8" to gasket surface - double checked tonight.
I'll double check the spark plug tonight.
My old plug wire had separated from the boot, so I used the how-to on the website to cut away the top of the coil plastic, and re-solder on a new wire. Spark was strong when I put it all back together before running it.
When I had everything apart I had the guts of the muffler out, and cleaned.
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Bullfrog - 05/20/09 at 11:02pm
Timing by the marks/point gap method is "good enough" . . . sort of. Just note that the way you "see and align" the marks may be different than the way I "see and align" the marks - which would result in different timing settings.
Point gap method is probably better, but there is some user skill and "feel" involved there (and some other small things way too wordy to describe) which can result in different timing when different guys do it the same way.
The "power" of the timing light is that you get to truly SEE what the actual timing of the spark is -- so it is most certainly the best method to confirm that you have it right.
I have no problem setting the timing by either of the above methods . . . and going out to run the bike hard. but that is because I've proven over time that I won't accept thoughts like, "Geez, I've adjusted the points 4 times now and they still aren't opening at exactly the right time . . . but they ARE pretty close . . . aw heck with it, that's good enough! Let's close 'er up and go riding." No. Adjust 'em that 5th or 6th time . . . till you get it right. Then its OK to run it. If there is any doubt - hook up the timing light.
We still don't know the compression. Install compression gauge. Make sure spark plug is contacting the head (good ground), depress kill button, hold throttle wide open. Kick er over till compression stops climbing. I'd guess 1/2 a dozen kicks will do it. NOTE: not kickety-kickity-kick which is very hard on the kick roller retainer. Take a full kick, then another full kick, repeat, repeat. Low compression will leave the engine kind of gutless.
Ed
PS: Roger Lippiatt's Hot Tip for "re-wiring" the coil is a good one huh?!!!
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Mark Potter - 05/20/09 at 11:25pm
So.. Dumb question - how does one know if they have the points timing right or not?
I'll borrow a compression gauge from someone at work. I don't have one myself. But - how does the spark plug grounding factor into things? I'm just thinking I've only got so many hands.
Also - I don't have a kill switch - do I need to worry about that?
Tonight I pulled the plug and cranked it over a couple of times to check spark - it was nice and strong - and when I accidentally grounded myself into that circuit - it was the strongest spark I've ever felt myself - one of those that makes your chest jump and both arms go weird.
The plug itself looked OK - dark brown\black - a little sooty, not oil fouled, but definitely darker than the nice tan you like to see.
I also put my thumb on the hole, just to see, and it blew it off with pretty good force and a nice pop. I realize that's not even close to scientific, but it makes me wonder.
Let's say the compression is good, I get the timing right, the points are right, the plug gap is right, the carb is clean, is this likely just an issue of proper jetting \ adjustment, or am I missing something?
And you're right about that 'hot tip', until I saw that I was a bit worried about my coil situation.
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Mark Potter - 05/22/09 at 12:43am
OK - so after another round - I know these to be truths:
Compression - (tested cold) - test 1 - 135lbs, 2 - 145lbs, 3 - 150lbs, 4 - 150lbs.
Points - gap was small - around .008 - I opened them up, ran a fine file on them to be sure they were nice and clean, and enlarged to .013, book says .012 - .015;
Plug gap was spot on.
Baffle - I pulled the exhaust, pulled the baffle, and double checked - its dirty, but not obstructed by any means. I also ran some chain through the engine end of the pipe to be sure there wasn't something stupid like a bees nest in there. Again - dirty but not obstructed.
So - I think I've ruled out anything downstream of the carb. I haven't road-tested it yet - as its 11:30 and the neighbors might not like me - but could the points have made that big of a difference? I assume that with the gap being too small, they were opening too late, perhaps by 10 degrees, which I know will be a bigger difference at high rpm, but I don't have much experience working with them to know what kind of difference they can make.
Also for what its worth, the bike has less than 4,000 miles on it.
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bobwhitman - 05/22/09 at 12:55am
Unlike with most of us, in the case of old Hodies, sometimes "it ain't the mileage it's the age." Lots of crud, stickum and general degradation can occur over 35 years...
Stay with it; let us know how it runs tomorrow!
Bob in OR
PS: compression sounds OK, gap sounds OK...
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Mark Potter - 05/22/09 at 1:22am
but she's so pretty!
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Mark Potter - 5/22/09 at 9:29pm
It appears it was the points \ timing.
I had no spark when I went to start it this evening, so took the side case off again, and the gap was off, so re-set to .013, and it fired right up. Rode it around for a few minutes, then pulled the cover again to verify the gap was correct. Afterwards I rode about 10 minutes for some dinner, and then took a 30min ride on side roads around home.
Riding it - the clutch is slipping a little bit - not sure if its the oil I'm using (yamalube), or if my adjustments are off, or if it's just cleaning off some gunk from sitting. A lot easier to fine tune with the thing running and making power though.
I moved the needle clip lower to the middle slot, but I think I should move it to the #4 slot as it says in the book. I was getting a little bit of the fluctuating engine speed and a little lack of power at middle throttles, so I think she's running a bit lean.
At the end of the ride, the exhaust got loud and seemed to have opened up a bit near the head, so I'm not sure if it just came loose after having it off last night, or I really was running lean and did something to the copper o-ring or what, but when it cools down I'll take a look.
Anyway - thanks again to everyone that has helped me sort through this.
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