Carb/Float? Troubles

[BIGREDGUY]

Ok guys, I'll try to make this one short and sweet. Helping a buddy fix up a 125 Tri Moto. I had it running, it would start right up and run poorly, and eventually die (acted like it was flooding itself out). Eventually it would not restart even after resetting the carb mixture to factory. I pulled, disassembled, and cleaned the carb as well as tinkered with the float (was lost on the float adjustment even with the manual). Put it back together and she won't burp, but now blows oil/fuel out the exhaust with each pull, which is awesome. It has excellent spark. Any thoughts? I hate this little POS :drool: Why I stick to four stroke Hondas..

[El Camexican]

Find the float height (likely 20 to 22mm), but don't take my word for it. Watch a "how to" video on youtube and set it. Set the needle clip in the middle slot and open the air screw 1-1/2 turns. Pull the plug and spin the motor, its full of fuel, be ready for it to spray out of the head. Put a dry plug in and try starting it. Tune from there.

[BIGREDGUY]

Yep the float height is 21 on this one which I think i managed already with the help of a video and the mixture is tuned to spec as well. Also when I shut the fuel off the mix stops shooting out the pipe. Are there any other explanations as to why it is coming out the pipe? In any case I will pull the plug and drain it to dry it out s bit. Thank you and additional ideas are more then welcome!

[BIGREDGUY]

I'm now getting it to fire over for a few seconds only if I tip it to the right but it dies off and throttle does nothing. Any help 2 stroke guys??

[El Camexican]

Are you sure your float isn't leaking? You mentioned turning on the petcock and having fuel flow out the pipe. If you mean the stinger end of the pipe that's a whole lot of fuel. Did any fuel shoot out when the plug was removed and you pulled the cord?

[BIGREDGUY]

I pulled the carb yet again and the float must not of been closing initially when the fuel was leaking out. That part is fixed. And surprisingly, no, nothing shot out of the cylinder with the plug removed. I've tried putting the float all over the place and richening/leaning the mixture and it is not helping, it will do its thing when its tipped to the right regardless. and throttle seems irrelevant when it is running for those few seconds before tapering off. When I drop the carb bowl it is about 2/3 or so full. Some oil will still drip/spray outof the pipe but not nearly as much.

[El Camexican]

Have you made sure the reeds aren't stuck? Is your fuel tank at least 1/4 full and the line flows without tipping the trick? That side tipping thing makes no sense:wondering How's the compression?

[BIGREDGUY]

I'm not sure how to check the reeds on this engine. I do know there is good flow to the carb from the petcock. Still need to check the compression but when I had it running decent the first time and was able to ride it for that brief moment it had a lot of pep, more than I would of guessed from even a healthy 125. So at this point what I know is that fuel is getting to to the carb but what is responsible for taking it the rest of the way on these little 2 strokes?

[El Camexican]

Basically the reeds are located in front of the carb. They rest on a triangular block and when the engine is off they sort of sit closed, but not always. When the piston goes up and creates vacuum they open and fuel and air rush in. When the piston comes down the pressure seals them up. If they are stuck, cracked, or won't close properly when under pressure, or open when under negative pressure the engine wont run. It would be the equivalent of a bent valve on a 4 stroke, but much easier to fix.

[Bren_downe]

When you get a moment, reed this(see what I did there?)
http://airfoolers.com/?page_id=222

[BIGREDGUY]

Thanks for the help guys I will look into it and check back.

[BIGREDGUY]

I messed with it a bit and really can't tell for sure if the reeds are closing properly, however there does seem to be vaccum when I cover the hole. On a side the float valve in this carb has no valve spring. I think all carbs I have worked on previously have had a spring opposite the tip and I am 99% sure I lost nothing during disassembly.

[El Camexican]

Yes it does have a spring. It is internal and sits under that tiny round pin. It needs to move and it needs to be extended when you measure the float height. If it is stuck in there at the compressed height you may have found your problem.

[BIGREDGUY]

Awesome I figured it out right before looking at your reply! That spring is compressed and I was able to get it running before finding that, by tipping it on its side with the gas turned off. After pulling it over and over and always dying it finally caught its breathe and blew all sorts of gas and oil out for about 15 minutes, with the gas still off, until it cleaned itself out. Looks like Ill be good to go as soon as I reset the float with the spring out. Thanks a lot for the help I appreciate it!

[El Camexican]

I love a good mystery and I'm a sucker for a happy ending. Looks like we had both:beer

[BIGREDGUY]

Yeah its running and idling and accelerating like a top but on a quick sidenote, any ideas on why it likes to jump and stall when put into first. Clutch adjustment didn't seem to do a lot.

[El Camexican]

I believe it has two clutches. The adjustment is on the secondary clutch and all that does is determine how much the clutch pack opens when you move the shift lever up. It's basically a clutch cable adjustment without the cable.

The primary clutch is where your problem likely is. Assuming everything else is copasetic in the assembly your problem is that it is already engaged before you are engaging the transmission. That clutch activates with RPM, so all bla, bla, bla aside your idle speed is too high.

Get the RPM as low as possible and then you should be able to shift it at idle without any big clicks, bangs or stalling and it should not move until you give it gas.

[BIGREDGUY]

Alright there is something loose inside the clutch cover that rattles with the idle of the machine. It is acting like the clutch never disengages (slowing down the machine slows down the idle and makes it want to die). It is like popping the clutch on a manual transmission. Whatcha got for me El?

[El Camexican]

You ain't gonna like it...

If the primary clutch is not disengaging it means that (if you're lucky) the springs that provide resistance to the shoes opening up are broken or sacked out and it is taking next to no RPM to engage them. If you are unlucky someone went into there and figured out how to make it a solid lump with a welder.

Now keep in mind I have never been inside a 175, but I do know that those clutches wear out and they are expensive to fix, so it would not surprise me if some butcher has been in there and did whatever it took to get it rolling. Then again I could be dead wrong and hope I am.

You're going to need to open it up to see what's going on in there, there is no other way. Based on what you might find and what that trike is worth I wouldn't even buy a gasket set until you know what's in there. Please post pics and make sure there aren't any left-hand threads in there before you get out the impact driver.

[BIGREDGUY]

Thanks a lot for the quick reply sir. I assume the 125 and 175 clutches are similar if not the same. How daunting of a task is it to open it up and check the springs?

[El Camexican]

Hang on a second. I took a look at the parts fiche http://www.partsfish.com/oemparts/a/yam/50038829f870021f60a098d4/clutch and I was wrong, it looks like you have only the one clutch and it works like a slipper clutch. I can't seem to find the adjustment on it. I see an adjustment on the shifter here http://www.partsfish.com/oemparts/a/yam/50038829f870021f60a098d4/clutch but I can't see how it would affect the clutch like it does on a 200/225. Weird that they went to 2 clutches after this style, slippers are really popular nowadays.

So back to your issue. I still think you need to open it up, but I don't know what you might find. Before you open it tell me this; If the trike is in gear and you pull the starter rope does the trike move forward?

Add: My guess would be that the trike moves when you pull the cord in gear that part #17 and all part #6's are where the problem is.

[BIGREDGUY]

When you pull it in gear the trike does not actually move but you can tell that there is added stress on the engine (lower idle, trying to move) but it will start without walking. When you give it slight throttle in gear, this is where that rattling takes place that I mentioned earlier. I would describe it almost like it is functioning properly in there and everything is just loose or coming apart. Also the adjustment is located inside a small round cover on the right side of the engine. Sorry if I'm giving you a headache with all this I know it gave me one. Thanks again for sticking with me!

[El Camexican]

Not sure what to tell you at this point. If it was mine I'd pull the clutch apart, change the balls and the disc that holds them. It looks like Yamaha still sells both, that tells you something right there.

At a pre determined RPM that clutch should be free wheeling. If its dragging at low RPM something is wrong. As we discussed before I am 99% sure that adjuster only relates to how much the shift lever separates the clutch pack when you move it.