On trip to PI motoGP 6 days of glorious riding through some of the best roads and worst weather OZ has to offer.
The 7th day should have been a day of rest, but instead
Turned on carb heaters in vic high country(Mt Hotham) due to low ambient temp with pockets of snow sitting in shaded pockets, next stop left carb pouring out fuel from overflow.
Everything felt really good though
Turned heaters off and arrived at next town
where still pouring out fuel.
Tried tapping bowl with no success.
Unpacked a weeks supply of camping gear and proceed to disassemble in carpark.
Put back together no leak great.
Started bike everything felt Ok although idling a bit slower than normal.
Set off and absolutely no power would not pull above about 5500 rpm.
Limped along being overtaken by all and sundry including B double trucks.
Pulled into a motel had some dinner and started disassembly checking everything jets looked clear, diaphragms intact reassembled and went to bed as too latre to start bike.
Turned fuel on and overflow pouring out again. tried to started and for the 1st time some sort of a mechanical rattle.
Admitted defeat parked bike and camping gear in storage at motel and pillioned home on back of mates BM 700 kms through stinking heat and bushfires.
Will return next week with ute to pick up.
Insights appreciated
Can't say about the no power, but it could have been as simple as a fouled plug from the flooding. The rattling might be from gasoline in the cylinder, same problem, from flooding. The flooding would be caused by a float problem, new needles and seats plus a proper float adjustment should fix the problem. Do an oil change too.
^^^ what the guru said
carb flooding = fouled plug and flooded cylinder.
the carb heater shouldn't have anything to do with it. inside the bowl it is just a pipe thru which the oil flows, no moving parts.
maybe the heat caused something to dislodge and stick in the needle?
or maybe a seat to dislodge?
i have a carb heater kit at home and it's remarkably simple, nothing in that should have a direct cause for your problem.
How did you go?
Been back at work since then.
Plan to head to Gundagai to pick up bike and camping gear on Thursday.
So that is nexr weeks project
What did you find with the float system?
Crap on the needles?
Crap on the float valve seats?
Crap = waxy deposits, dirt, rust or piece of decayed fuel line?
Float needles rubber tip eaten away by ethanol or carb cleaner? Have a close look at the rubber float needle tip. Does it look eroded/worn?
Punctured float?
Have you been running Shell V Power fuel or a carb cleaning additive?
All newish carb bits from recent carb overhaul, new fuel lines, filter, manual fuel tap and overrhauled fuel pump
Probably did use V power as trip was from taree via Oberon Cooma Orbost PI. return via Bruthen Hotham Mt beauty so bought whatever premium I could find.
fair bit of crap in bowl on 1st disassemby but no obvious blockages anywhere.no overflow leak on reassembly.
No power after carb reassembly.
Pulled carbs apart again in Gundagai again everything looked OK but major fuel leak from overflow.
Confession time.
travelled with tools spare plugs etc. when time came to use tools plug spanner to fit darmah not monster so didn't check plug.
Pulled apart again yesterday at home and looks like the bloody bowl drain screw was not done up so would account for copious fuel drainage.
Front pot plug looks to have cracked ceramic and on testing doesn't work.
so looks as though could be as simple as tightening drain screw and replace plug.
won't know for sure until I put it back together which will be a few days as I might as well replace throttle cables while pulled down.
Fingers crossed
garry
Howdit go Garry?
Just something to consider, having a carbed bike like yourself, I really value having a manual fuel tap I can acess on the run. Now and then, I'll be riding along and feel the bike missing due to flooding carb/s. I turn the tap off and keep going for 20-30 seconds which clears it up and then as the float bowls start to empty I turn the tap back on which slams the valves shut.
I would ditch the vacuum tap and get a manual tap you can easily access.
Nearly always works. I guess the hanging float needles get a wash as the bowls refilled, or something like that. The needle valves come up firmly enough to seal if your fuel pump works ok I guess. It feels like the pause when switching fuels on a dual fuel car as the bowl empties, telling you to turn on the tap again.
Another in line fuel filter helps too. A recent thread discussed this option (Javamooses' saga with his 2000 750).
All good.
New plug to replace the dead one.
Carbs blown out.New throttle cable and everything works as it should.
In the end it was probably just a dead plug and dirty carb.
Both issues should have been sorted in the rain in the carpark at Mt Beauty.
I do run a manual tap and will probably call in to bike shop this afternoon for an additionl filter.
What was the comment about Shell V power as when I am at home it is probably the most commonly used fuel
Anecdotal reports of rough running and gummed up carbs you heard in bike shops and magazines. I found that I had alot more flooding with it after testing fuels in my 900 over a few weeks of summer commuting. That was a few years ago, so things might be different now.
A Shell engineer shared how modern fuels in general are designed for high pressure efi rather than low fuel pressure applications like carbs. When I whinged to him, he accepted that additives that clean at high pressure could leave residues at low pressure. A mate that worked for a Mercedes dealership told me that his collegues called 98 V Power "diesel". Their customers were told not to use it. I have had occaisional flooding with other brand fuels
Shell might have fixed it, but I dont know anyone with a bike who uses it. We could all be acting on old info and bad perceptions unfairly based on the past.
Of interest, Shell are advertising a new formula for 98 V Power at the bowser.. Worth trying (with a Coles docket) ;D
In my experience, my carbed M750 is completely not particular about fuel. I can run about anything in it but it actually runs best on Ethanol free (yes, it is available here and there for a few cents more) 87 that about anything. There is a noticeable difference in running the 93 octane v. the 87 octane.
Glad you got it sorted, I chased a carb leak for weeks on my wife's NT650.
JM
Quote from: the_Journeyman on November 14, 2013, 07:20:31 AM
In my experience, my carbed M750 is completely not particular about fuel. I can run about anything in it but it actually runs best on Ethanol free (yes, it is available here and there for a few cents more) 87 that about anything. There is a noticeable difference in running the 93 octane v. the 87 octane.
Glad you got it sorted, I chased a carb leak for weeks on my wife's NT650.
JM
My carbs need an occasional set of needle jets and that's it. 93 fouls my plugs.
Quote from: howie on November 14, 2013, 09:51:08 PM
My carbs need an occasional set of needle jets and that's it. 93 fouls my plugs.
I probably should have specified, it runs worse on 93 than 87. I replaced my needle jets last winter because they were causing an overly rich condition and got an MPG increase as a bonus.
JM