Author Topic: fl350 falling on its face  (Read 2779 times)

odysforever

  • Newbie
  • *
  • Posts: 2
  • Karma: 0
    • View Profile
fl350 falling on its face
« on: October 07, 2013, 07:49:54 PM »
Bought an '85 fl350 in great shape with approx 7 hrs. on fresh motor. Ran like a scalded dog for 2-3 trips and slowly started losing performance.Acted like it was rich on low end first,then moved to mid-range,then fell on its face throughout throttle curve. Will start right up, and idle smoothly,as soon as you open throttle it acts like it is WAY rich...smokes like crazy(running 93 octane non ethanol fuel with Motul 800 2t @ 48/1) Won't even pull itself on the trailer. Checked carb and reeds, plug,coil,stater and spark exciter, and all check out fine.Has 127 lb.s compression.BTW Has a 1 mil over piston, Mikuni t38mm Sudco Racing carb 360 mainjet/triple E ceramic pipe and silencer. Now it is oozing a thick, black oil substance out of exhaust,and every slip joint in the pipe,especially at the exhaust head. Tried to lean it out with a 240 main and it ran pretty good on mid-range for 10 mins,then loaded up again,now no matter where you jet it,won't run. Is my crankcase full of fuel and separated oil??  Lost here !!!!!

jivy88

  • Newbie
  • *
  • Posts: 1
  • Karma: 0
    • View Profile
Re: fl350 falling on its face
« Reply #1 on: October 08, 2013, 08:13:15 AM »
I'm a Newbie to. Bought mine around 4 months ago. I had the same kind of problem. ran great at first but started boggy down on top end. I got my Odyssey in California and brought to Texas, So Elevation change may have had something to do with it. I went up with the main jet and that made it worse and it smoked like a old freight train. However, going to a smaller main jet cured it. I have a stock 32mm Keihin carburetor, and went from a 142 main down to a 138.  I didn't have oil coming from the exhaust either, I use 32:1 and that is what everyone has told me to run. I'm not sure but I have not herd of anyone running 48:1, which may be causing your smoking and oil out the exhaust issues.       

DMoneyAllstar

  • Newbie
  • *
  • Posts: 15
  • Karma: 2
  • Hello. My name is Dan, and I'm addicted to buggies
    • View Profile
Re: fl350 falling on its face
« Reply #2 on: October 08, 2013, 09:57:48 AM »
127 lbs is low.  Were you pull-starting it with the rope, or using the e-start to measure compression?  If e-start, was the battery fully charged?

What does the plug look like?

Not too much to pull the head and have a look at the bore/rings/piston, so may want to pull it and look.  The prev owner might not have drilled the lube holes in the piston, nor relieved the jug's exhaust bridge.

Check your fuel line tee?

To prevent yourself from frying an air-cooled 2-stroke, you need to do a leakdown check to check for air leaks, verify jetting with a plug chop session, and run a EGT sensor/gage.
'85 FL350R Odyssey
'88 LT500R Quadzilla

Corn, beans, wheat, and trees - no sand!

DMoneyAllstar

  • Newbie
  • *
  • Posts: 15
  • Karma: 2
  • Hello. My name is Dan, and I'm addicted to buggies
    • View Profile
Re: fl350 falling on its face
« Reply #3 on: October 08, 2013, 10:10:19 AM »
And regarding the spooge in the exhaust...the Motul 800 is a synthetic ester oil has a pretty high flash point (485'F), so you'll have some oil that may not get full burned and will accumulate as spooge downstream.  If you're racing it (literally) and running it hard/hot constantly, it would be fine and the accumulation minimal.  But if you're just trail riding and what not, I'd switch to something with a lower flash point and still decent cold/hot viscosity like a Golden Spectro (171'F) or Amsoil DOM/INT synthetic (216'F/120'F, resp).  I don't like any of the castor oils like Maxima or Klotz -- they have really high FP and they smell funny, lol.  Just because the bottle says "Racing oil" on it, doesn't necessarily mean its big, bad, and better.

But first and foremost, verify that compression, check for air leaks, and verify jetting.

Added later: the new top end may not have been properly broken in, too.
« Last Edit: October 08, 2013, 10:16:39 AM by DMoneyAllstar »
'85 FL350R Odyssey
'88 LT500R Quadzilla

Corn, beans, wheat, and trees - no sand!

LiveWire

  • Administrator
  • Hero Member
  • *****
  • Posts: 978
  • Karma: 20
    • View Profile
    • 85 Honda Odyssey FL350 Parts
Re: fl350 falling on its face
« Reply #4 on: October 11, 2013, 03:08:37 AM »
As DMoneyAllstar pointed out, were the lube holes drilled, exhaust port relieved? What was the piston to wall clearance set at?

Based on that nothing changed expect a loss of power, I suspect the answers to the above are not yes, yes, .005".

odysforever

  • Newbie
  • *
  • Posts: 2
  • Karma: 0
    • View Profile
Re: fl350 falling on its face
« Reply #5 on: October 28, 2013, 01:50:36 PM »
Took me looking everywhere else, but finally found the problem.....the silencer was clogged up !!!! took it loose from the pipe and BAM engine roared back to life !! It's the Triple E ceramic with the long silencer....can these be re-packed?? If not where can I buy one ?

odypilots

  • Sr. Member
  • ****
  • Posts: 344
  • Karma: 6
    • View Profile
    • Downhomeracing.com/opr
Re: fl350 falling on its face
« Reply #6 on: October 28, 2013, 02:18:28 PM »
That's great that you found the problem!

I don't have any experience with that silencer, but you should be able to tell if it comes apart. It'll have screws of some type, or pop rivets that you can drill out.
The usual 'my two cents' disclaimer applies. :)