Author Topic: Hard starting  (Read 5743 times)

tuckersteel

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Hard starting
« on: January 01, 2004, 03:19:03 PM »
I have a 350 which requires dumping some fuel down the air intake to get it to start when it is cold. Once it is running, it will start no problem within the first few cranks. I need some advice on where to get started to solve this problem.

 Tucker

ludedude

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Hard starting
« Reply #1 on: January 01, 2004, 04:39:14 PM »
Loosing the fuel in the bowl after sitting for a couple days?

Loosen the drain screw on the card and see if any fuel runs out. It should. If not....leaky drain?

Low float?

350nut

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Hard starting
« Reply #2 on: January 24, 2004, 07:07:52 PM »
I agree, have you checked the float levels?hows your fuel pump?have you replaced it lately?have you checked the fuel pressure, it should be a steady stream like the size of a pencil but in a pulse form.if you need a carb stock in great shape email me I got 1 for you in perfect shape.Try to disassemply the carb and CHECK the internals out, it sounds to me that your carb is the problem.

Joe Odyssey Rider

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Hard starting
« Reply #3 on: January 25, 2004, 07:20:29 PM »
This is interesting reading. I have 2 350s and both are exactly like this. I also have 2 250s and that are the same. If any of them sit for more than a couple of days or so, they will not start without "priming". I have rebuilt the carbs on all 4. The 250s we bought brand new in '84 and they've always done this. I got the 350s about a year ago and just figured this was normal. Now, they (the 350s) will start with the starters, but only after much cranking. I just figured that I'd save on battery and starter wear (anybody that has taken a starter out knows why starter life is of utmost importance!) by "priming" them.

So, you're saying that 350s should start right up, even after they've sat for a considerable period of time? I've always wondered where the fuel goes ... it acts like the bowls are completely empty. I've tried all kinds of fixes ... turning the gas off after hoping it wasn't "siphoning" back INTO the tank, etc.

I don't think it's the float levels, they run perfectly otherwise ... why would the 250s be any different?

Oh, BTW, the fuel lines are always empty also.

350nut

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Hard starting
« Reply #4 on: January 26, 2004, 03:07:41 PM »
If your lines are empty, CHECK the 3 way valve in the fuel line, make sure it is operating properly.I would bet if it is, your float needs to be changed.Also, are the carbs stock, aftermarket?If they are stock, CHECK the throat in them- there should be a plastic guide for the slide in there, if it isnt there, the slide will rotate around in the carb, you wont let the bowls fill up with fuel because tyhe slide isnt sitting in the proper location, thus not allowing fuel to go INTO the bowls.Try this, after they sit for a day or 2, before you start them drain the bowls,if there isnt fuel in there, your float level and float valve are bad.If there is ample fuel in there, REPLACE the 3 way valve and buy a rebuild kit for your pump, there really cheap at partsfish.com or randy at odysseysalvage.com.You can also try this as well---afetr sitting, take the fuel line of the carb, CHECK for fuel in the line,if there is thats good, if non try cranking it, the fuel should be there within a couple cranks of the motor,if there isnt ample fuel pressure your pump is bad or as I stated your 3 way valve isnt allowing the fuel to get to your carb and it is just recycling it back to your tank.Also, are your gas caps vents operating properly, a bad cap will cause a condition like this as well, have you checked them out?

Joe Odyssey Rider

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« Reply #5 on: January 27, 2004, 12:40:30 PM »
OK, here we go, line by line:
 
>If your lines are empty, CHECK the 3 way valve in the fuel line, make sure it is operating properly.
 :arrow: They seem to be ok. I had a bad one with the 250s and got a real education on how they should be hooked up and working (I got a bad one when I ordered a replacement ... that's another story for anothre time ... I just about never figured it out)

>I would bet if it is, your float needs to be changed.Also, are the carbs stock, aftermarket?If they are stock, CHECK the throat in them- there should be a plastic guide for the slide in there, if it isnt there, the slide will rotate around in the carb, you wont let the bowls fill up with fuel because tyhe slide isnt sitting in the proper location, thus not allowing fuel to go INTO the bowls.
 :arrow: Stock carbs on both the 350s and 250s. BTW, these are completely stock except for the air box mod on the 350s and subsequent required jetting changes. I'm pretty competent at rebuilding the carbs and float levels/float valve settings. The plastic guide is in place for all 4 and seem to be doing their job.

>Try this, after they sit for a day or 2, before you start them drain the bowls,if there isnt fuel in there, your float level and float valve are bad.If there is ample fuel in there, REPLACE the 3 way valve and buy a rebuild kit for your pump, there really cheap at partsfish.com or randy at odysseysalvage.com.
 :arrow: Again, there is not any fuel in the bowls nor the lines. And, I'm pretty sure all 4 3-way valves are good to go.

>You can also try this as well---afetr sitting, take the fuel line of the carb, CHECK for fuel in the line,if there is thats good, if non try cranking it, the fuel should be there within a couple cranks of the motor,if there isnt ample fuel pressure your pump is bad or as I stated your 3 way valve isnt allowing the fuel to get to your carb and it is just recycling it back to your tank.Also, are your gas caps vents operating properly, a bad cap will cause a condition like this as well, have you checked them out?

 :arrow: Now this I haven't tried yet. I suppose the pumps could be bad ... but 4 bad pumps? Seems unlikely but I will CHECK this out with the 350s. Note that all 4 run great once I get them running. As for the bad cap, I had that happen with one of the 250s. Took a long time for me to figure that out ... it would run just fine for about 15 sec to a couple mins and then just quit. Was nice to have spare parts to swap out. I'll CHECK out the 350s caps, though. I would imagine that I could just remove the caps and try cranking them over? My fuel lines are clear, it would be quite obvious I would think.

Thanks for your suggestions, I've lived with the 250s doing this since they were brand new. I just figured the 350s were the same.

350nut

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hard starting
« Reply #6 on: March 23, 2004, 06:02:08 AM »
hey, you ever figure the problem out with the hard starting?was it the floats, pumps, 3 way valves?Are you still having the same problem?Have you replaced all the fuel lines by chance, if the are weakened by sitting there may be peep hole leaks that are causing you to lose "prime"in them,meaning the pump has to work that much harder to fill the fuel bowls in the carbs at initial start-up.Get back to us, I am very curious on this and havent seen a posting for you in a while.

Joe Odyssey Rider

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« Reply #7 on: March 25, 2004, 12:26:25 PM »
Sorry I haven't gotten back sooner.  I tried all the suggestions and nothing.   The carbs (or rather the float bowls) seem to be completely empty.  The fuel lines were all replaced with clear line (like you suggested, the original lines were crap ... but that had already been done), so you can easily see if fuel is flowing.  There seems to be a fair amount "squirting" when turning over, but it does seem to take several "cranks" for that to happen.  

If I dribble just a little fuel down through the air cleaner, it will fire immediately and generally quit.  One more dribble and it runs like it's been running all the time.

It really seems as if the pumps were weak or something.  But why would both go at the same time.  On the other hand, both run great once they're started.

Oh well, off to the dunes this weekend, I'll experiment some more.

Thanks for the suggestions.

ludedude

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« Reply #8 on: March 25, 2004, 01:58:39 PM »
I think that there is a fuel flow test in the Pilot manual, is there one in the FL350 manual......take the line off and measure how much fuel comes out when you crank the egine for so many seconds....

How about putting a primer bulb in line like often done on older sleds?

350nut

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Hard starting
« Reply #9 on: March 25, 2004, 03:11:09 PM »
The diaprams inside the pumps will deteriorate over time, the pumps should stream fuel out like a steady squirt,not intermentant.If you are priming the carbs and the motor stays running it may indeed be that the pumps diaprams are weak and cannot pump enough for start up, but are suppying enough fuel to keep it running.Does it run out or is it fuel starving when you go on long passes under full throttle?

Joe Odyssey Rider

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« Reply #10 on: March 26, 2004, 01:44:54 PM »
Lude ... I think the old bulb thing might be my best choice.  Didn't know snowmobiles had them, but my little "toy" boat's tank uses one.

Mudbogger ... They do not run out of gas.  We made a full throttle pass down the entire wash we run in at the dunes ... probably about 2 miles wide open with no problems.  BTW, all this info applies to both my 350s, they are virtually identical in this regard.  One has maybe 30 hours on it, the other I did a top end job on it, 1st over lots of hours but still on the original tires.

ludedude

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Hard starting
« Reply #11 on: March 26, 2004, 01:55:13 PM »
let us know if it works

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Hard starting
« Reply #12 on: March 27, 2004, 07:50:31 AM »
Have you actually checked the fuel bowl levels, i THINK THEY ARE 16MM or something to that, its in the manual.I agree, if the pumps were bad, it would starve for fuel so mudboggers idea ok but seems not like the problem.Get back to us,PLEASE.

redrider

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hard starting cold
« Reply #13 on: March 28, 2004, 08:51:23 PM »
You may wish to check compression while cold.  It was suggested to me once that one of the symptoms of low compression is difficulty starting when cold.  I found it could be overcome buy feeding it extra fuel or starting fluid on start up.  I'm not sure if the extra fuel allowed for a better seal around the rings until it began to run or not, but it WAS the case.  After the engine does begin to run and heat up, things expand and seal off better.  My Pilot suffered from this.  It was a large pain in the butt to start but when it did it ran well from then on out.  Hot or warm starting was a breeze, let it cool down completely and it became hard to start again.  The last time I checked it hot it was around 140.
After purchasing a new compression gauge I checked my compression when cold and sure enough it was down to 110!  Wow, I thought, compression hot was down to 132.  I found out later that the gauge I was using was WAY off, about 8-10 lbs. (but then it was my father's and was as old as me I think).  
Anyway, check the comp and see if that may have a bearing on the issue.
Good luck.

Joe Odyssey Rider

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« Reply #14 on: March 30, 2004, 10:05:46 AM »
One of the 350s has about 135 compression and the other 130.  I'm at 4600 feet elevation, so I don't think they have low compression.  (Honda manual states 138 is normal)

Again, they will start up fine if they only sit a day to 3 or 4 days or so.  Much longer than that and they need to be primed in order to start (unless you want to really "grind" on the starter for any length of time.  The fuel lines appear to be empty also.

They act like the fuel just evaporates or something.  I haven't actually rechecked the floats, but wouldn't they run "funny" if the floats were set too low?  And, wouldn't that problem be present all the time, not just after sitting for several days?

If I understand what you guys are saying ... your 350s can sit for a month (or longer) and when you go to start them, they fire right up, like in 5 seconds or something like that?

Also, like I stated before, my pair of 250s have also done this from the day we bought them brand new.  But, I read this is typical of 250s on other forums (I know ... a bad thing to do!).

So frustrating!    :cry: