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Discussion Starter · #1 ·
hello . hoping some one can help .
i have read some posts about this hoping soem one would have had the same problem and there would be a simple one hit solution
but at this stage im struggling ot get my cl350 running any thing like corectley,

problem
it runs- badly. the left hand cylinder heats up quicker then the right , and sounds a bit lumpy. but any thing over 3k rpm it seems to stumble and cant go any further
also after a re build on the carbs [ will get to that ] i have tried setting each one up indecently with the opsite side having its spark plug removed
it runs one one crab. but the adjustment on the lick over needs to be pretty much max out. and then the revs slowly rises a little before after about 3-4min it cuts out , and wont re start
i think i have either flooded the cylinder or ran out of fuel,
although adjusting the fuel pilot screw, seemed to have little or no affect, im amusing that having it fully in would starve the fuel mixture quickly . but ti doesn't .
the same problems happens on the outher side
and runing both carbs after setting them up on my bench. works but a gain , it cuts out after a while and doesn't climb on the revs - and the rhs down pipe seems to take a little longet to get hotter
and in all situations , the spark plug , look v coked up with soot after a short while of running the bike

what i have done

cleaned the tank. there is a steady drip from off the petcock feeding the carbs, i think it would be enough
fitted new intake manifolds on the engine , new points, and set them up, new plugs. [ good strng spark on both ]
and re built the carbs.
the kit i got , wasn't quite the same as the old ones, and some bits didn't fit right . cleaned and also put most of the small bits in a ultra sonic cleaner . but the only parts that i wasn't 100/ happy with were 3 little o rings, that were a little to perished for my liking
making a seel on the bottom of the main jet, secondary jet, and the tiny one on the inside of the pilot screw. was a bit backed. but i taught it would be ok. as i did with the others./
but with isues i might be wrong . there all sitll in place, but they wont ba as tight as they once would have been

any ideas ?
thanks
 

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Improper fitment is a common issue with aftermarket carb kits. In your case authentic Honda gasket/seal kits are available and reasonably priced. Just google the part number:

16010344690

When you open the petcock you should get a steady stream of fuel, not a drip. When you have a petcock with two spigots and no lines connected fuel may stream out of only one spigot. When you plug that spigot fuel should stream out the other spigot.
 

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I'd agree with JT as it sounds like you might not be getting enough fuel through the petcock? Do the lines fill with fuel or is it just a continual drip down?
 

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Discussion Starter · #4 ·
althow i had cleaned the tank i only put a few pints of fuel in to it. so drained it as it had some flash corrosion in there again.
and took the valve apart. it was loaded with crap . gave it strip clean inc the little gause filter , and put it in a little untra sonic cleaner , and it looks like ,new.

thanks for that advice
hopefully it will run a but more reliable when i put it back on on saturday.
at the moment i have cider viniger in the tank, and i plan to drain that out , stick a jet wash inside and give it a real good going over , to remove any debre and rince it out,then immediately go over and inside the tank with a hot air gun to dry it out as soon as possoble to stop any flash corosion
and then back on the bike and fill up to the top with clean fuel. then i should be ready to go ...
any advise on setting up the carbs ?
 

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Discussion Starter · #5 ·
cleaned the tank and it looks like new inside. and have excellent fuel flow
but still having problems. .
the carbs have been cleaned and either im missing something. or there could be something else wrong as i have no history on the bike at all
i have taken the spark plug out of the right hand side and thought i would set up the left hand carb.
now am i right in thinking there is only 2 adjustments you can make. the idel screw, and also the fuel screw. im finding that to start with , i have to have the throttle held open to maintain even low rpm between 1k - 2k. well above were the ajustment screw can take it.

and also adjusting the fuel screw seems to do nothing . from one extreme to the far end

side note with both cylinders working .. it wont go much above 3k
 

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Discussion Starter · #6 ·
Worth noting that the bike came with 2 sets of carbs . Have fitted and cleaned the 2nd set ... No change thow . I did use all the jets out of the first set . ( Checking that they were still clean ) .
Any advise any one .
 

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On 350 carbs, IF the O-rings don't SEAL the jets into the casting, then you in essence are running much larger jets........

On ANY carb, IF the mixture screw has NO effect, the passages are still clogged, OR your throttle stop screw (idle screw) is set too high/open, and you are using the principle/main jetting rather than the slow/idle jetting....

I always run both cylinders when adjusting the carbs, one cylinder will almost never run properly DRAGGING an open cylinders parts weight along.......
 

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Discussion Starter · #8 ·
On 350 carbs, IF the O-rings don't SEAL the jets into the casting, then you in essence are running much larger jets........

On ANY carb, IF the mixture screw has NO effect, the passages are still clogged, OR your throttle stop screw (idle screw) is set too high/open, and you are using the principle/main jetting rather than the slow/idle jetting....

I always run both cylinders when adjusting the carbs, one cylinder will almost never run properly DRAGGING an open cylinders parts weight along.......
Thanks for the advise .
Getting tired of opening them up looking for something I have missed . The o rings on the bottom of the 2 jets are not new . And I'm happy to replace them . Althow I'm not 100% sure it will fix the issue. As they are snug and there is some resistance when pushing them home .

The fuel screw seems to do nothing . Althow I'm having to hold the throttle half open to keep it ticking over .
As well I have had to fine tune the points again as it wasn't firing on the left . And the left hand side carb may have not been entirely full but I'm not 100% confident there both firing or ballanced at a given moment . In not sure .but seem fine when I check the plugs against the earth on the bike .
It has moments for a second or so , were the revs go high ( with the throttle constantly half open ) then back down to about 1k again .
Have watched the you tube clips by common-motor . A few times now , looking for were I have gone wrong . I'm still thinking it's a fuel / carb isue . But all I keep doing is striping them down rebuilding them , same results .. it's starting to wear me down
Realy want to do it my self . And learn something . But I'm thinking now , . Maybe I need to take it in some were .
Was hoping to get it running . And have a quick dash one it . To see if it's for me . Before spending a lot of time and money on a restoration .
Never had a bike this old before . Maybe it's not ment for me:confused:
 

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Have you EVER had the bike running?
There a lots of things that need to be correct for it to run.
Having Spark does not mean you have enough spark or spark at the proper time.
The End Caps that connect to the Spark Plug often loose the connection to the wire.
This can typucally be corrected by un-screwing them from the wire and cutting back 1/4-3/8ths of an inch then screwing them back on

Spark Plugs can show a perfetcly good "LOOKING" Spark but not allow the spark to jump the gap under compression.
New Spark Plugs are cheap and worth using when trying to get a bike to run.

Another possibility for the mixture screw having no effect is the fuel level in the float bowl being way off.

What Model Carbs do you have - You didn't say?
Also you didn't mention what year your bike is.
The common models for you bike depending on the year could be any one of:
350
3C
722A

The Carb Model Number is cast into the side of the carb body.
I agree with 66 Sprint that if you did NOT repalce the O-rings you may be pushing a rope uphill.
Typically the O-Rings and the needle & seat for the fuel inlet are the ONLY parts that need to be repalced when rebuilding carbs.

Two VERY Common errors in rebuilding these carbs are:

A):
Soaking the entire Carb Body and then NOT Oiling or Greasing the FELT Washer that seal the throttle shafts allowing for a Vacum (air) Leak behind the throttle plates.
Meaning air getting into the intake without being mixed with fuel.

B):
Incorrect Float setting from NOT holding the carb body on an ANGLE as described in the FSM (factory service manual)
The TIP of the Fuel Shut Off Needle is SPRING loaded and the weight of the float often compresses that spring and results in approx. a 2 mm error in the float setting - Unless you hold it at an angle to prevent that from happening.

It is worth noting the relationship of the Measured Float setting is an INVERSE one.
The Float hangs UPSIDE DOWN in the float bowl.
Meaning the greater the space the lower the fuel level in the bowl and Vice-Versa.

Too high a level and the jets will pull too much fuel resulting in flooding
Too low a level and the jets will starve for fuel resulting in a lean condition.

Both will make adjustment VIA the Mixutre screw next to impossible.
 
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Have you checked all the electrical connections for the coils and such? I did my carbs twice chasing an issue that turned out to be loose connections that were making the bike not firing well.
 

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Discussion Starter · #11 ·
its never ran right , no .. the carbs were off the bike when i got it ..
it also came with an incomplete set as well
one of the spark plugs were missing so got 2 new ones for the bike , also checking them one gets soot'd up v easley. and the side that doesn't seem to heat up as well is a bit , but is normally damp. so i fitted new points. but against the engine casing i can see the plugs fire up wit ha good spark, and turning the engine over by hand, it seems to spark at the correct time as well.
the bike is a 72 and the carbs are the late design, from the common motor vids : watching
i set the floats up in the same way, with a micromoter . to 23mm
although i get what your saying if the fuel level is to high .. will try and lower lower them 1mm and see if that helps .. it cant hurt
as for the felt washer . ...
i had no idea there was on there,, haven't stripes that part down.. will certainly look in to replacing these,
and also didnt know the carbs needed to be at angle .. some thing else for me to look in to .
genuinely .. .thanks for the advise
 

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Discussion Starter · #12 ·
Have you checked all the electrical connections for the coils and such? I did my carbs twice chasing an issue that turned out to be loose connections that were making the bike not firing well.
well i t looks like it sparks well and in time when i turn it over by hand.. but its worth me taking off the tank and checking and cleaning up the connections.. it does seem like at some times one of the cylinders isn't right will check it out thanks
 

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Discussion Starter · #13 ·
Have you EVER had the bike running?
There a lots of things that need to be correct for it to run.
Having Spark does not mean you have enough spark or spark at the proper time.
The End Caps that connect to the Spark Plug often loose the connection to the wire.
This can typucally be corrected by un-screwing them from the wire and cutting back 1/4-3/8ths of an inch then screwing them back on

Spark Plugs can show a perfetcly good "LOOKING" Spark but not allow the spark to jump the gap under compression.
New Spark Plugs are cheap and worth using when trying to get a bike to run.

Another possibility for the mixture screw having no effect is the fuel level in the float bowl being way off.

What Model Carbs do you have - You didn't say?
Also you didn't mention what year your bike is.
The common models for you bike depending on the year could be any one of:
350
3C
722A

The Carb Model Number is cast into the side of the carb body.
I agree with 66 Sprint that if you did NOT repalce the O-rings you may be pushing a rope uphill.
Typically the O-Rings and the needle & seat for the fuel inlet are the ONLY parts that need to be repalced when rebuilding carbs.

Two VERY Common errors in rebuilding these carbs are:

A):
Soaking the entire Carb Body and then NOT Oiling or Greasing the FELT Washer that seal the throttle shafts allowing for a Vacum (air) Leak behind the throttle plates.
Meaning air getting into the intake without being mixed with fuel.

B):
Incorrect Float setting from NOT holding the carb body on an ANGLE as described in the FSM (factory service manual)
The TIP of the Fuel Shut Off Needle is SPRING loaded and the weight of the float often compresses that spring and results in approx. a 2 mm error in the float setting - Unless you hold it at an angle to prevent that from happening.

It is worth noting the relationship of the Measured Float setting is an INVERSE one.
The Float hangs UPSIDE DOWN in the float bowl.
Meaning the greater the space the lower the fuel level in the bowl and Vice-Versa.

Too high a level and the jets will pull too much fuel resulting in flooding
Too low a level and the jets will starve for fuel resulting in a lean condition.

Both will make adjustment VIA the Mixutre screw next to impossible.
just a quick question were abouts does it say about the angle being correct in the FSM , i have been looking around pages 55 onward, to do with the carbs. but cant seem to find it ?
 

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its never ran right , no .. the carbs were off the bike when i got it ..
it also came with an incomplete set as well
one of the spark plugs were missing so got 2 new ones for the bike , also checking them one gets soot'd up v easley. and the side that doesn't seem to heat up as well is a bit , but is normally damp. so i fitted new points. but against the engine casing i can see the plugs fire up wit ha good spark, and turning the engine over by hand, it seems to spark at the correct time as well.
the bike is a 72 and the carbs are the late design, from the common motor vids : watching
i set the floats up in the same way, with a micromoter . to 23mm
although i get what your saying if the fuel level is to high .. will try and lower lower them 1mm and see if that helps .. it cant hurt
as for the felt washer . ...
i had no idea there was on there,, haven't stripes that part down.. will certainly look in to replacing these,
and also didnt know the carbs needed to be at angle .. some thing else for me to look in to .
genuinely .. .thanks for the advise
I did it off this video and it was wrong. You need to hold it at an angle so the float is not compressing the needle and measure it that way.
 

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well i t looks like it sparks well and in time when i turn it over by hand.. but its worth me taking off the tank and checking and cleaning up the connections.. it does seem like at some times one of the cylinders isn't right will check it out thanks
Mine did well revving it in neutral, but when I rode off it went to crap in about 1 min. Turned out the connections were a bit dirty or lose and the vibrations would cause it to misfire or such. Fixed the connections and it was off to the races.
 

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Discussion Starter · #16 ·
Thanks .. will look up online on how to set up the floats , if your saying that video is wrong .. watched a few of those you tube clips by common motor, seem very clear and simple to follow ..
Had no idea those fibre washers existed even ..
 

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Discussion Starter · #18 ·
I see what you mean now . , Opened up the carbs again on the weekend and ajusted the float . Worked out about 3mm difrance . while they were off I put some "wd40 lithium geese" all around the felt washer , and had some suction on. Whole opening the valve . Didn't seem to take much in.
And I'm still waiting for the new o rings . For the bottom of the main and secondary jets . To arrive.so made a tight seal using loctite thrad . But. Sadly it's made no difference. There right side cylinder had stopped firing ( the points wernt makeing contact any more , so in ajusting it . And realy tightened it up . And I may now have striped the threads . I will probley re drill and tap the plate and put a bigger bolt throw for now . But I called it a day and checked you tube and the internet for ideas ..
A few people said about difrent jet sizes . And althow I'm sure there fine .. I'm not 100% sure . So have ordered a new kit with all parts for both carbs . The last kit I got only had a few bits in that would fit. So re cleaned the old bits and re used them . No idea if they were right . These new ones are for the 722a carbs as I have .

And I don't know is this is right . The Wight of my floats don't depress the needle on the fuel float.

The fuel will open and close just fine . But holding the carb on the desk , or at a 45' angle . It's the same measurement. But I understand if the floats were a little heavier, how it could affect set up
 

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I understand that it may seem not to make a difference but Honda felt it was important enough to add that to their manual.

Ths 350 FSM and their CARB Spefic Manul both reference holding the carb body at an angle.
This is from the Carb Manual and is the best graphic and explaination of the process I have seen.

Float Adjustment.jpg
 

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Discussion Starter · #20 ·
I know , it makes sense .. have just took them off to triple check .
I'm within 0.06mm on both sides of 26mm checking at a steep angle .. although flat down it still reads the same . Either way . It's not the cause of the problem . Apart from the old jets being way out . I can't think of much else IMG_20190401_171144.jpg
 
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