Main IndexAuto Repair Home Search Posts SEARCH
POSTS
Who's Online WHO'S
ONLINE
Log in LOG
IN







Search Auto Parts

99 yamaha yfm 350


  Email This Post



chickenhouse
Enthusiast

Apr 22, 2015, 4:05 PM

Post #1 of 15 (20910 views)
99 yamaha yfm 350 Sign In

Bought this bike new, has run fine for years but now giving me a starting problem. Factory batteries cost more than I'm willing to pay so I mounted a lawn & garden battery in the rear. Have been running it this way for 3-4 years now. Problem is, it is hard starting. Cranks over fine just won't start. Eventually it will fire but cranks so long, I'm afraid I will wear out the starter before it runs. Here's the kicker to me. Pull the rope 1 time and it's running. So, why don't I just pull the damn rope? It has no compression relief and I have no grip. I can't pull the rope. We have separated the ignition from the starting systems and run separate batteries on each system. No change, did not matter. Checked starter and found it to be within proper draw readings with brushes in good shape. Have had carb off and settings rechecked(as in the float setting) to no avail. Pull the rope and it starts right up. It also runs fine when it starts. It's in another man's shop now, giving him a shot at it. It is used mostly for mowing my yard. I pull a 5 foot swisher mower behind it. I'm having to use my 87 Yamaha 225 for this chore until we figure this out but that machine is too light for the job. Flipped it once. Have tried 2 separate batteries at the same time and also a boost on ignition side of wiring with no difference. How he separated these systems and tried starting, I don't know as I was not present when he did. I do have confidence in this guy as he has solved most all of my small engine problems in the past.


Discretesignals
Ultimate Carjunky / Moderator
Discretesignals profile image

Apr 22, 2015, 5:14 PM

Post #2 of 15 (20899 views)
Re: 99 yamaha yfm 350 Sign In

Just curious, but does this thing have a good spark when your cranking it with the starter using a spark tester? This thing probably has an igniter and a coil. Maybe watch coil and igniter supply voltage to see what happens to it when your using the starter. May need to get your hands on a scope that can catch the issue. Starter loads the engine block, so also make sure your grounds are good too.

What triggers the igniter to fire the coil? Is there a sensor or pickup for the igniter? If so, is it a hall effect or variable reluctance sensor?

edit:
Just googled and it looks like it has a stator that produces an ac signal to the igniter. Just like the old ford duraspark ignition systems.





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.

(This post was edited by Discretesignals on Apr 22, 2015, 5:40 PM)


chickenhouse
Enthusiast

Apr 22, 2015, 5:52 PM

Post #3 of 15 (20888 views)
Re: 99 yamaha yfm 350 Sign In

Yes, does have a pick up coil mounted on the charging coil. I replaced that once but has been some time ago. Has spark using tester. It looks good.


Discretesignals
Ultimate Carjunky / Moderator
Discretesignals profile image

Apr 23, 2015, 1:52 PM

Post #4 of 15 (20868 views)
Re: 99 yamaha yfm 350 Sign In

Is the spark able to jump at least a 3/4 inch gap while cranking the engine with the starter?

If you have a scope, capturing the coil primary, coil secondary, and pick up sensor signal would be interesting to see if everything is within sync cranking the engine by hand and with the starter.





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.

(This post was edited by Discretesignals on Apr 23, 2015, 1:59 PM)


chickenhouse
Enthusiast

Apr 23, 2015, 2:01 PM

Post #5 of 15 (20863 views)
Re: 99 yamaha yfm 350 Sign In

I wish but not available.


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Apr 23, 2015, 3:02 PM

Post #6 of 15 (20859 views)
Re: 99 yamaha yfm 350 Sign In

CH - You just know I'd come up with some off the wall thought for this. What thing turns that detects when to make spark? I ask and these are NOT my thing but got a great, NEW yap powered generator FREE no less (my style) that sat and fuel was left on and both overfilled oil but someone tried to electric start the thing and dang woodruff key sheared in its crank (damper of sorts) so timing was working but off and no adjustment on that just needed that item in one only spot and wasn't. Lost hair and more of course but was just that.


Note - that took just some (nothing really broke) hydraulic lock and the weak link was the silly key to crankshaft just cut it and locked nicely in the wrong spot!


It's one thing that can give you good spark, good compression, fuel known and not run - that's all. This really isn't my thing but don't send stuff out unless it's impossible to figure out,


Tom



chickenhouse
Enthusiast

Apr 23, 2015, 6:13 PM

Post #7 of 15 (20851 views)
Re: 99 yamaha yfm 350 Sign In

You got the best kind Tom-free! This thing as I said runs great- when you pull rope to start it. I have started it using the starter but it seems to pull all the juice away from spark or something, but it will start right before you burn the starter motor up cranking it. Pull it once and it starts fine! I told him tonight to take a started screw out and make a temp jumper wire from starter mount to either batt grnd or separate frame grnd to see any diff. I'm under the weather now, went in for ultrasound, it's a boy, no gall stones or any gall bladder problems BUT, Doc says shingles. SH t! This id gonna hurt. 4 diff meds so far. ointment runs $145. Won't need the bike for a couple of weeks so far.


nickwarner
Veteran / Moderator
nickwarner profile image

Apr 24, 2015, 6:20 AM

Post #8 of 15 (20838 views)
Re: 99 yamaha yfm 350 Sign In

I would bolt a ground right to the engine case and jump it to the battery. Few years back my Yamaha was pulling the same sort of BS. Wouldn't start off electric starter. Only fired on the kick starter. This is an 1100 so its all I've got at 200 pounds to do it. A new ground cable was the fix, but it wouldn't work going to the frame. Had to go directly to the engine case.


Sorry to hear about the health issues. Shingles won't be fun. I'm glad I got chicken pox as a kid so I can cross that off my list. I just finished my run of small engines this week to get back to the cars. Hoping my lawn dies so I don't have to bother to get my lawnmower running. Hang in there CH and it was nice to see you back on here.


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Apr 24, 2015, 12:59 PM

Post #9 of 15 (20830 views)
Re: 99 yamaha yfm 350 Sign In


Quote
I'm glad I got chicken pox as a kid so I can cross that off my list.


I think you have that backwards Nick. Previously having Chicken Pox is what makes you susceptible to Shingles. The virus is already in your body. They have a preventative shot you can get now though that greatly reduces the Shingles problems.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



nickwarner
Veteran / Moderator
nickwarner profile image

Apr 27, 2015, 7:18 AM

Post #10 of 15 (20812 views)
Re: 99 yamaha yfm 350 Sign In

I guess I do have that a bit backwards. Good thing I'm not a doctor, my patients would be screwed.


chickenhouse
Enthusiast

Sep 5, 2015, 3:51 PM

Post #11 of 15 (20353 views)
Re: 99 yamaha yfm 350 Sign In

Right you are Nick, require payment up front if you doctor anyone! Shingles gone, bike is running. I took it home and got a new stator and put it in. Stator has a pick-up coil mounted in it. I looked but could not find that part alone for sale. So, the new stator fixed it and grass is getting mowed again. Thanks again guys! Bill


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Sep 6, 2015, 3:07 AM

Post #12 of 15 (20339 views)
Re: 99 yamaha yfm 350 Sign In

CH! I didn't ask when this thread was new and almost don't dare. Just what creation or idea is a MOTORCYCYCLE if engine still in a bike doing mowing a lawn?


I see the monster pull behind "REEL" mowers that power bladed by the wheels of them not the machine towing them. Fine but can't think of those working on tall grasses at all?


Tom


chickenhouse
Enthusiast

Sep 6, 2015, 9:08 AM

Post #13 of 15 (20332 views)
Re: 99 yamaha yfm 350 Sign In

Tom, it's not a motorcycle, but an atv- 4 wheeler. 350 cc. My lawnmower is a Swisher brand that cuts a 60 in ch path. I blew up the original engine twice. Hole in block as patched with JB weld after the first time, then it sucked a valve, ending it's carreer. It was a 14 hp. I then installed a 19 hp B&S. Cuts rather well!
Over 20 years old


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Sep 6, 2015, 9:57 AM

Post #14 of 15 (20328 views)
Re: 99 yamaha yfm 350 Sign In

Pics probably wont show but saw this thing finally! Dang mower has it's own engine, blades and really doesn't care what the heck pulls it along and saw you can add a couple of these mowers to a mower such that you get a 15 foot wide cut!


OK - Just never in my life saw that style. Here you see mechanical "REEL" type or some PTO units with blades not reels.


Get it now. Still surprised in the duration of this thread and problem you could cut anything without a brush cutter about now!
Pic of what you should have or similar.........



We know I'm in low open area MA but still tons of golf courses and some farms would "hay" that much land not make it a lawn.


Just me - not popular here then or now this way. Yes MA monster McMansions have lawns like that but @ 15M (million bucks) you don't cut your own grass!!!!!!!!!!


Tom



chickenhouse
Enthusiast

Sep 6, 2015, 12:10 PM

Post #15 of 15 (20320 views)
Re: 99 yamaha yfm 350 Sign In

That is what mine looks like. You can also "offset" the mower to run down pond banks and such or like you mentioned, offset it and pull with another mower "cutting
your mowing time!






  Email This Post
 
 


Feed Button




Search for (options) Privacy Sitemap

shopify
site analytics