Spark Problems

[allyce]

Yamaha 175 Tri-Moto

I think I have my engine problems pegged, but still having difficulty. It died on me mid ride a couple weeks ago.

Gas good
Carb getting Air
Kill Switch Good
Coil Good
CDI Good
Engine is getting gas
Spark Plug New

Now, the spark plug WILL spark to the frame but not in the engine...
When I pull the plug out of the engine it is wet with gas. So I know the fuel is fine.

Does that mean I have grounding problems?

[Dirtcrasher]

Thats really odd... If it sparks outside of the plug hole and to the engine, then the ground is definitely good.

If you turn the gas off and shoot a bit of fuel in the head will it sputter??

It could still be a fuel problem like flooding.

[allyce]

We really don't feel it to be a fuel problem because we have tried spraying starting fluid directly into the carb and it doesn't even like catch on for a minute and then die out. It just wont start period. No sputtering

Although I didn't try sparking it to the engine, I just did it

If the engine was flooded why would it give out during riding on me? I was not going up an incline. The tank was half full. I had been riding it for a good 20 minutes, not aggressively either. Just trail riding through the woods.....

[Frankencelery]

Here's how I do this spark test.....I remove the plug and plug it into the wire, and lay the plug against the fins of the engine. If it won't stay, I clamp a jumper cable to the engine and the other end to the plug where you put the wrench on it. Then I pull the starter and see if it *really* sparks like it should. This way, you're testing the spark AND the plug.

Having said that, I had a problem with my ATC90 last year where it would stop sparking intermittently. I was fortunate enough for it to happen while I was doing the test above, and I traced it to a bad connection where the coil wire went into the coil. I pulled the wire out, cut about 1/2" off the end of the wire, and put it back in, gluing it in place. It's been solid ever since. Your results may vary, of course!

[allyce]

Thanks for the advice but I already have cut off the end of the coil wire and reattached it. I am about running out of ideas......

I just don't get why it would spark to the frame and to the engine fins but not in the engine.......

Maybe my CDI really is bad...

Does anybody have a manual for a Yamaha Tri Moto 175 that they could scan some pages for me?

[ceaserthethird]

If it's a 2 stroke try the reeds - Check to see if their broken

This happen to me and it would not start !

[PaTriker]

If it is wet with gas and you have spark, then you are flooding it!

[Frankencelery]

I don't agree with your theory that it's not sparking when it's in the engine. If you tried a test similar to what I described and it sparks, then it should also be sparking when it's in the engine. In that case, it must be flooding...try turning off the gas and then once you know the carb is dry, spray a little starting fluid and see how it responds. If it fires, then you know it's a flooding problem. Keep us posted.

[Frankencelery]

Oh, and caesarthethird, how do you check to see if the reeds are broken? I've never owned a 2-stroke.

[sandrion]

sounds like it is just flooding if its sparking well to the fins and the frame

[Daddio]

It is definitely a flooding problem. With a 2stroke the fuel air mixture goes into the crankcase before going into the cylinder. I have actually seen them have flooding problems and problems running too rich even after rebuilding the carb because of excess fuel in the crankcase. Try turning off the fuel and draining the fuel from the carb, then remove the sparkplug and kick it for a while to dry out the cylinder. Then put the plug back in and turn the fuel back on and then try to start it . You might try turning the fuel on for about ten seconds and the turn it back off. This will get enough of fuel into the carb to get it started but not enough to allow it to overflow into the engine.
Are you running an air filter?

[allyce]

I will give this a shot thanks daddio.

This will be my first time working on a carb. From what I have researched my carb doesn't have a drain screw. It appears that I must take the entire bowl off the bottom. Anybody have any tips for me? I am not the dumbest girl when it comes to engines but I am also not the most experienced when it comes to working on engines...

[DeePa]

best way to check for good spark is pull the plug, plug it into the boot, pull/kick the starter while holding the plug.

if it gives you a good zap, youre set.

[ceaserthethird]

She's getting spark, Do you have Manual for it.

Does any one know if this is a 2 Stroke or 4 Stroke ? ? ? ? ?

[allyce]

Okay I drained my carb and pulled the start a bit and then put the spark plug back in and still nothing. I even tryed rolling it down the hill and shifting (yes I know it isn't smart to do but i wanted to make sure it just wasn't me not being strong enough). Still nothing.

Its a 2 Stroke. No airfilter (It ran for weeks without one so I really don't think thats the issue especially when it gave out mid-ride). No manual

This was a hand me down junker that I have been slowly putting life back into. I will take some pictures this evening to show you guys. :)

Maybe my reed valves are broke. I will try tonight.

[Daddio]

If your reeds were broken you would have quite a bit of air blowing back out of the carb.
Running without an air filter will cause premature death of any engine. Get one if it's not too late.

[allyce]

Below is my trike and below that is the carb

http://farm4.static.flickr.com/3293/2783240114_c7ee642ae4_m.jpg
http://farm4.static.flickr.com/3155/2782383499_ae814b942b.jpg

[y2kane]

is it a blue spark or is it a yellow one. With good compression it can blow the yellow spark out without firing. It needs to be a good blue spark. This is the same issue I am having with my big red. yellow spark outside and it won't start. Everything is good on it so it must be a wiring issue for me. I just haven't tracked it down yet. good luck.

[allyce]

Nope its a beautiful bright blue spark

[Atc GuY]

I drowned my 110 in water once and water got into my cdi. All I did was hook it to my riding lawn mower drop it in 2nd and pull it around the yard until gas was brought back into the cylinder. Sounds hillbilly-ish but after 10 mins of pulling it over anything sounded better. Try this: pull the plug spray starting fluid into the cylinder and keep the gas off. Reinstall the plug and pull it over it should pop if it's getting spark!

[allyce]

New Developments:

Tried spaying the starting fluid directly into the cylinder. No pop but still sparks to engine. A friend commented that it could be a compression issue. I can plug the spark hole with my finger without much effort while pull starting. I took off the carb and got to the reeds. Noticed there wasn't a gasket. The reeds look okay however they don't form a nice seal (I used a flash light at the sides). The piston was moving okay and looked fine but that was just through that 3 inch opening. I have never taken an engine apart.

I am hesitant about taking the engine out. Do you guys have any tips for me. Should I just buy new reeds now? What could be my biggest issue (most expensive)?

Any help is greatly appreciated :)

[Atc GuY]

A 2 stroke is the easiest to rebuild. Just pop head and jug off, replace rings, have jug honed and re-install. Re-install and your done. It shouldn't cost more than $40 for a hone. Reeds and rings arn't expensive. It still may be electrical. CDI's RARELY go out, but I've seen coils just die... I don't know, If your shure spark is good and it's getting fuel than reeds may be the only thing left to check. You shouldn't be able to keep you thumb over the plug hole while pulling it over.

[Texas 200x]

Get a compression tester and go from there. Make sure to open the throttle all the way when testing.

[allyce]

it's ALIVE!

Wow what an afternoon I have had. I went to the auto store and rented a compression tester. It was at 6psi. So then made a gasket for the reeds and tested again. Still 6psi. Not good. I then over then next few hours I took the motor out and started taking apart the cylinder piece by piece. when the head was off i inspected the gasket and everything seemed fine. No warping. the piston looked great as well as the cylinder (dammit). I then reluctantly continued taking things apart until i freed the piston from the top of the cylinder. I notice the rings didn't expand when I took them out. It appears something had gotten jammed on the side of the piston and warped the metal which held the rings in (like a gouge). I carefully pryed the rings out and lightly sanded the groves so they could move freely. (Keep in mind the messed up part was no more then an 1/8th inch wide) Reassembled the entire motor and hooked up the tester. 50PSI! Hooray! I put the motor back in a the trike ran like a champ again. :w00t:

Just wanted to thank you guys for all the helpful tips! Its been a long road but I can finally ride again :)

[bad350]

Don't Want To Rain On Your Parade But From What You Described It Probably Won't Run Long, If I Had The Engine That Far Apart I Would Have Put A New Set Of Rings In It At Least, Just My .02 Anyways I Hope I'm Wrong And God Luck!

[allyce]

Oh yeah I am absolutely getting new rings and probably a new piston but it atleast I will have it running for a bit. Don't want to run it into the ground though before I can get those. I also need what i think are bearings on either side of the piston. There is nothing there and it kinda wobbles ever so slightly.... It just seems like there should be spacers or bearings or something. I am no mechanic. Frankly i suprised the hell out of myself with this big troubleshooting event that has consumed my free time for the past month. The only good thing out of these problems is now I know so much more about engines and my trike. I have confidence that if other things happen that I can handle it for the most part. I guess what they say is right. Knowledge is power

[bad350]

I Think What You Are Talking About Is The Wrist Pin Which Probably Has Some Wear, And A New One Will Come With A Piston Kit But Even With A New One Your Gonna Have A Little Play Not Sure But It Probably Has A Top Rod Bearing In It Also That Will Need To Be Replaced And They Are Cheap

[Daddio]

Don't forget to get yourself an air cleaner for that thing. ;)

[allyce]

yeah i hope to pick that up this week. i need to find a air intake elbow or try and fashion one myself. Anyone have recommendations for air filters? I assume that any filters for the 82-84 tri 175's will work. My yamaha dealer wants $58 for one. I think thats a tad steep myself....

[Atc GuY]

Glad you got it running!

[Nick_R_23]

yeah i hope to pick that up this week. i need to find a air intake elbow or try and fashion one myself. Anyone have recommendations for air filters? I assume that any filters for the 82-84 tri 175's will work. My yamaha dealer wants $58 for one. I think thats a tad steep myself....

I used to run UNI air filters on machines that were missing the airboxs, they are universal fit and also have a spring inside so they will bend around the frame or other things that would be in the way with a normal filter. You should be able to pick one up at an ATV parts dealer, or have them order one for you. They are pretty cheap also I think.

-Nick :TrikesOwn

[allyce]

I went to the yamaha dealer today and found a UNI for 18.50. The dealership didn't have it so they are 2=day shipping it to me with no additional cost. I also found a hose that I was missing to connect the filter box to the carb for 4 bucks on ebay. Things are moving nicely.

[Dirtcrasher]

I used to run UNI air filters on machines that were missing the airboxs, they are universal fit and also have a spring inside so they will bend around the frame or other things that would be in the way with a normal filter. You should be able to pick one up at an ATV parts dealer, or have them order one for you. They are pretty cheap also I think.

-Nick :TrikesOwn


I never felt the spring was there for "bending around things", I always thought it was to prevent the filter from collapsing or vacuuming itself closed......

[Nick_R_23]

I never felt the spring was there for "bending around things", I always thought it was to prevent the filter from collapsing or vacuuming itself closed......

Yes, you are right, but Ive found that the spring works great for getting it in tight places, where a normal 'solid' one wont fit. It worked awesome for what I needed so what can I say?? :lol:

-Nick :TrikesOwn