Cafe Racer Forum banner

1 - 12 of 12 Posts

·
Registered
Joined
·
204 Posts
Discussion Starter #1
I finally got it running but the left carb fires sparadically. When I would spray starter fluid into the carb, it would fire right up and run great. Also the more throttle I gave it, the slower it would rev (to an extent). It is getting fuel. Im thinking the floats are wrong, but which way are they wrong? too high or too low and is that really my problem? Any hints or tips?
-JP
 

·
Premium Member
Joined
·
11,267 Posts
JP,
The fact that it fires when you use starter fluid tells me it may not be getting the fuel that it needs. A float level anywhere in the ballpark is usually good enough for the engine to run decent. Have you removed and cleaned the carbs? Checked the jets carefully to make sure they are not clogged? Have you removed the float bowl to look for dirt/water etc. Does the plug indicate it's running too rich or too lean on that cylinder.
JohnnyB
 

·
Registered
Joined
·
204 Posts
Discussion Starter #3
I am a novice and rebuilt them this winter. They are totally clean and pristine. I didnt keep it running for very long so the plugs dont show anything really. I messed around with the float level today and got it to run on both cylinders. I think the fuel mixture needs to be adjusted as well as synching the carbs. Not to mention I need new points too. I think the combination of those is my problem. but anymore advice would be appreciated

-JP


Edited by - rad350hog on Mar 24 2004 7:49:34 PM
 

·
Registered
Joined
·
13,809 Posts
a float level anywhere in the ballpark.....john, thank god somebody finally had the sack to put that into text. ive always thought that and i continuosly see peole screwing with float heights like they are crucial. i think youre totally right though. jp, keep going. it should idle if its not synched, but on throttle run like shit. especially right off of idle. mixture's important. make sure the screws are backed out the same. on the idle screw too. make sure the jets arent clogged. you could have picked up something from the cleaning. isnt it fun to get a bike fired up fro the first time!!!

jc
 

·
Registered
Joined
·
8,067 Posts
If the bike runs great when you spray starter fluid and assuming you have the the slide open to spray it in. I would work backwards a little and start with the main jet when you cleaned the carbs what did you use. I would make sure the whole in your main jet looks like the one in the side that runs good with out starter fuild. The work back on the other jets and needles. This is a Honda 350 twin right?Joe tell me if I'm wrong but aren't vacuum seal thingies real important with these bikes?

Aaron
 

·
Registered
Joined
·
13,809 Posts
yeah, good point, you have a good carb, use it as a reference. the only important vacume issue is really the slide and diaghpram, and that thing can be pretty ragged and still idle. it just wont run at speed. when the pressure builds, the slide wont move, so it runs like crapola. it sounds like for some reason its not picking up gas, so its either a clogged jet issue, the idle screw is turned too far down, or the mixture screw is way off. or, the seal at the carb and intake is totally shot. but i think it'd have to be missing to not work that poorly. if you can spray gas in it, its not an iggnition probably. most likely. id say 99% not iggy. it sounds like youre going to right direction with it. keep working on it. you got the timing cam thing figured out and that could have had you stumped for a while.

later
jc
 

·
Premium Member
Joined
·
11,267 Posts
JC,
To tell the truth the only problems I've ever seen associated with float level are A: So low it sucks the bowl dry at WOT and B: So high it pours out of the overflow.

I guess technically float level can have an effect on overall mixture...high float levels require less vacum signal to pull a given amount of fuel...and the reverse for low levels. But under race condition with the fuel in the bowl dancing around like a crazed hillbilly a few mm is hardly going to make a difference.

JP,
I assume you have a service manual for the bike. Make sure the idle mixture screws are adjusted at the proper starting point...usually something like 3/4-1 1/4 turn out. The manuals usually give a figure like that as a starting point to begin making final adjustments.

Also check the idle speed screw if those whacky CV carbs have them...look down the carb throat to make sure the slides are close to the same... or just sync them up like you say. Check your low speed jet...they are tiny tiny with almost micro scopic holes, I've seen tons of them clogged. I have one of those things that doctors use to look in your eyes and ears that I use to check the jets.

Carbs are funny things, I've gotten where I can take an old school Keihin 18-26mm and just clean them, whoop them together and they work. Most OEM carbs are so simple that if they are not working it's a fairly obvious cause.
JohnnyB
 

·
Registered
Joined
·
204 Posts
Discussion Starter #9
Turns out the carbs on my bike arent the same ones that the manual says came with the engine. I had the floats set to what my manual said. Well it was wrong so I got them to the right height and it would fire up and run, but weak on one side. Replaced the points and it ran better but still weak. Found out finally that the wire of the one breaker point was shorting on the cover. Duh! Fixed it and now im just waiting for some good weather.


-JP
 

·
Registered
Joined
·
204 Posts
Discussion Starter #10
Turns out the carbs on my bike arent the same ones that the manual says came with the engine. I had the floats set to what my manual said. Well it was wrong so I got them to the right height and it would fire up and run, but weak on one side. Replaced the points and it ran better but still weak. Found out finally that the wire of the one breaker point was shorting on the cover. Duh! Fixed it and now im just waiting for some good weather.


-JP
 

·
Registered
Joined
·
13,809 Posts
thats always a good one. that drove me nuts for a few hours one day. i stacked a couple of gaskets under it and problem solved. the points will actually arc to the cover and short it too. thats one nice thing about the electronic iggy, no points arcing. but there are drawbacks to both i suppose.

jc
 

·
Registered
Joined
·
13,809 Posts
thats always a good one. that drove me nuts for a few hours one day. i stacked a couple of gaskets under it and problem solved. the points will actually arc to the cover and short it too. thats one nice thing about the electronic iggy, no points arcing. but there are drawbacks to both i suppose.

jc
 
1 - 12 of 12 Posts
Top