first of all, Happy New Year to everyone. Safe riding and let`s hope breakdowns are few and far between!
My 97 monster 400 won`t start...have checked the battery, all good, checked plugs etc... have a good spark at each cylinder so it`s a fuel issue.
What is the best way to check fuel delivery to the carbs ( I had the carbs overhauled 18 months ago so I`m pretty sure they aren`t the problem ) and how can I check that the vacuum pump is working?
The fuel filter was last changed 2 years ago so that may be ready to be replaced.
Thanks
Mike
What kind of fuel tap does it have?
hey koko
this type
(https://s28.postimg.org/vnpbdrapl/20170102_154741_resized.jpg) (https://postimg.org/image/vnpbdrapl/)
happy new year!
Happy New Year. [beer]
It's worth replacing that vacuum tap with an in line manual tap. Those vacuum taps either jam shut or leak fuel into the cylinder via the vacuum line to the manifold. Hondas used a similar type which often starved motors.
Bypass it and see if fuel flows. Otherwise it will be your pump but that's less likely. Check the tap's vacuum line is ok.
I have seen a few float needles glued shut by old fuel congealing in the bowl. Strange but true.
hey Koko
thanks. will bypass the fuel tap and see what happens. I will drain the float bowls too. It`s a 1997 monster with most of its original parts so I am expecting some issues to crop up.
safe riding
Mike
bypassed the vacuum fuel petcock...no joy.....
fuel filter changed too but still wont start. double checked battery etc..all good there
vacuum fuel pump? should i bypass this and run the fuel line directly from the tank to the carb to see if this is the issue?
For test purposes, yes. Just make sure the fuel level in the tank is higher than the carbs.
thanks Howie
do i need to remove the air filter housing to get to the fuel inlet? I really hope not as it is a major pain.....
jan 30 th update
too cold to work on the bike recently..... wimp i am!
anyway....installed new fuel petcock ( non vacuum ), new fuel filter, new vacuum pump, all new fuel lines...... bike still won`t start. checked battery, all good and good spark on each plug...... engine cranks but just wont fire...so could it be a carb issue? I had the carbs overhauled by ducati 2 years ago and have only done 2000 kms on the bike since then......... any ideas before i called the most excellent motovita bike shop in north osaka and ask them to take a look?
Have you verified that you're getting fuel to the carbs?
How long did this bike sit since the last time it ran?
Try priming the carbs with gasoline, a drop or two down each venturi. It can take a long time for the float bowls to fill.
Stock carbs have floatbowl drain screws that can confirm fuel is reaching the carbs. Very handy. +1 on the carb priming.
hey guys
thanks for the replies...
fuel is definitely reaching the carbs as when i remove the fuel line from the carb, gas comes out. I will double check via the float bowl drain plug as suggested.
bike stopped running in mid december so hasnt been fired up for 6 weeks
i will try and prime the carbs tomorrow and see what magic ( or not ) happens.
fingers crossed and thanks again.
update.... checked the battery again, all good... undid the float bowl drain screws...lots of gasoline... checked spark...both good....but still doesnt start.... carbs bunged up? i want to take it to my local duc guy but wifey has just bought airplane tickets for our summer hols and i have been given strict instructions not to spend more money on bikes so any suggestions as to what to check next? i was thinking could it be fouled jets or some gunk clogging the carbs internally somewhere?
Did you try putting some fuel in the carb mouths as suggested? Are you using the enricheners/choke?
It's likely the pilot jets are clogged if the bike fires with some fuel dripped in.
Also, did you pull the spark plugs and look for fouled plugs?
A change of plugs is a ten dollar tune up and worth doing[thumbsup].
Possibly, clagged jets or float needles glued shut by stale fuel as DP suggested. I've seen pilot jets completely sealed with fuel wax and float needles glued up in the closed postion by jelled fuel.
hey guys
plugs were on the dark side...a little too dark for my liking so gave them a good clean with a wire brush and checked the gap with feeler guages...plugs are only 6 months old.
hey ducp..... i havent tried that as I can see gasoline in the venturi but I will try that next. How much fuel per venturi? a few mililiters?
have you tried squirting the carb with "carb cleaner"? try that first ...
report back
next try
use caution this may be a little risky
.... try ...removing both plugs; clean plugs .... put a little gas (few drops) directly in the plug holes; reinsert plugs; cross fingers ... press start ...
repeat maybe increasing gas
report back
Quote from: samuraibiker on February 08, 2017, 08:32:21 PM
hey guys
plugs were on the dark side...a little too dark for my liking so gave them a good clean with a wire brush and checked the gap with feeler guages...plugs are only 6 months old.
hey ducp..... i havent tried that as I can see gasoline in the venturi but I will try that next. How much fuel per venturi? a few mililiters?
Yes, a few drops, 2 or 3, of fresh gas in each with clean/fresh plugs.
If it doesn't at least fire, then fuel is not the issue.
thanks again for the advice.... will try that asap
Quote from: samuraibiker on February 10, 2017, 04:31:43 PM
thanks again for the advice.... will try that asap
I'v been waiting to hear ... but no posts; hope you didn't blow yourself up with gas ... :o
hey guys
sorry for the slow reply..... mad mad snow here in japan so have been doing a lot of snowboarding.... my other passion besides motorbikes and jazz!
anyway....fuel in the cylinders and she fired up!!! so its deffo a carb issue..... got out the trusted haynes manual but to be honest, it really isnt that clear about how to remove the carbs so any advice would be appreicated, especially detaching the throttle cables from the carb itself ( this is the point that Haynes is very vague about )
Leave the cables on the carbs and detach them from the throttle barrel instead. There is a bit of work getting the carbs off as the airbox/battery box must come off first.
Maybe you can leave it all in place and working from underneath remove the float bowls and then the slow jets if you are careful. Moving the oil cooler out of the way will help.
hey koko
i was thinking the same.... with my vespa i can get to the jets without taking the carb off. I have a 400 so no oil cooler. Is it possible to access both pilot and main jet from beneath? I have checked many threads about duc carb cleaning and they all recommend removing the carbs.
Your tip about removing the cables at the throttle end is a good one , looks much easier that detaching them from the carb itself.
so, next step.... float bowl covers off, pilot and ( hopefully ) main jets removed and cleaned whilst carb is still attached, reassemble and fingers crossed! If no joy, carb comes off the bike for more detailed cleaning.
It isn't impossible to work on the CV carbs installed on the bike. It's the way I was taught.
Helps if you have a lift.
Main jets are not the issue...pilot jets.
Pilot/slow jets have pin holes to flow through and are easily waxed shut by old fuel. It would be difficult to play with the main jets with the carbs in place and would be easy to make the beast with two backs up. Just try clearing the pilot jets to get the bike going and pour some carb cleaner into the tank.
Quote from: koko64 on March 01, 2017, 06:05:50 PM
Pilot/slow jets have pin holes to flow through and are easily waxed shut by old fuel. It would be difficult to play with the main jets with the carbs in place and would be easy to make the beast with two backs up. Just try clearing the pilot jets to get the bike going and pour some carb cleaner into the tank.
You can do mains too...really.
I know. I've done them with the carbs in place, but I'm trying to keep it simple for SM to stick to the essentials. The main jet holes are pretty big and usually carb cleaner in the tank and a good ride should do it, but I have seen quite a few sets of pilot jets waxed shut.
I absolutely agree he should ignore the mains for now and concentrate on the pilots.
Quote from: koko64 on March 01, 2017, 06:05:50 PM
Pilot/slow jets have pin holes to flow through and are easily waxed shut by old fuel. <snip> Just try clearing the pilot jets to get the bike going and pour some carb cleaner into the tank.
I absolutely disagree with...
Quote from: koko64 on March 01, 2017, 06:05:50 PM
<snip>It would be difficult to play with the main jets with the carbs in place and would be easy to make the beast with two backs up.
quite a nice discussion going on!
so, going to remove the float bowl covers with the carbs still attached to the bike, get those pilot jets out, give em a blast, wack some carb cleaner in the tank with new gas, stand back and hit the starter........fingers crossed!!!
Good luck. [thumbsup]
Quote from: koko64 on March 01, 2017, 08:19:26 PM
Good luck. [thumbsup]
The hardest part, sometimes, is getting the screws out. :P
Put a rag over the front cylinder as the screws want to hide between the fins. Many replace the screws with stainless Allen bolts.
Quote from: koko64 on March 02, 2017, 09:31:33 AM
Put a rag over the front cylinder as the screws want to hide between the fins. Many replace the screws with stainless Allen bolts.
I couldn't find stainless when I did mine...I did lube up the threads on some mild allen screws. Ddan was able to get them out when he put the carbs on hiss SS track bike.
You did not mention it but when you drained the float(s) did you check for water in the gas? I would think it a more likely cause then recently serviced carbs.
Quote from: samuraibiker on March 01, 2017, 07:20:51 AM
sorry for the slow reply..... mad mad snow here in japan so have been doing a lot of snowboarding.... my other passion besides motorbikes and jazz!
anyway....fuel in the cylinders and she fired up!!! so its deffo a carb issue.....
pew glad you were busy boarding not burning (kidz )... pics of snow / boarding / carbs and bike needed I think ... [popcorn]
Glad to hear got you started! ta da! If I don't say so "me" self... I doooo get some credit ;D
If even for a brief moment; there is the fire of life in the beast; then there is hope. dn17 [Dolph]
... did you try the squirting of the holy carb cleaner? easiest route; less assembly required ...
Iv taken a couple of carbs apart and cleaned; but not a duc carb ... so I'll leave it to the wiser to debate