Carburator sync/clean

CJhaughey

Have you seen this spec page?
http://www.motorera.com/honda/h0400/cb1.html
Says mains 105 and pilot 35.
Might be worth trying a set of 105's

Richard tea

Thanks lads. I reckon they might go 98 95 95 98 or vice versa. Cj I haven't seen that site or spec before. Handy site though. It's slightly off with spec though. I spent a good while checking out float heights today and I'm 99% sure they should be 21mm. Sure they are plastic floats and I do think think u can adjust them anyway. I checked float valves and they are fine. I'll double check carbs are clean. Fit new rubber boots and throttle cables. If she doesnt run smooth after that I'll admit defeat and get it to a pro.

Richard tea

Hotblack Desiato wrote: »

I remember hearing that some air cooled fours used to have different jet sizes between the inner and outer cylinders - the cooling of the inner cylinders wasn't as good. Surprised if a water cooled bike would be set up like that though.

I think you are spot on. I reckon the bigger bore jets go in the centre carbs. I need to find out if 98 or 95 is the bigger bore.

CJhaughey

Richard tea wrote: »

I think you are spot on. I reckon the bigger bore jets go in the centre carbs. I need to find out if 98 or 95 is the bigger bore.

98 is bigger bore, Keihin use fractions of a millimeter. So your 98 jet is 0.98mm

Richard tea

Thanks cj. Do u reckon if I had the jets in the wrong sequence that it would have caused my rpm problem. As in would it show as a fuel starvation problem?

CJhaughey

Richard tea wrote: »

Thanks cj. Do u reckon if I had the jets in the wrong sequence that it would have caused my rpm problem. As in would it show as a fuel starvation problem?

I just think its very strange that there is two different sizes of jet, Most if not all modern machinery runs the same size jets in the bank.
Main jet should not affect starting that much, at startup the pilot and choke circuit is operational, main jets only for higher engine speeds.
What size pilots are in yours?
Another source of info..
http://www.cb1.cun.net/Descargas.html

Richard tea

CJhaughey wrote: »

I just think its very strange that there is two different sizes of jet, Most if not all modern machinery runs the same size jets in the bank.
Main jet should not affect starting that much, at startup the pilot and choke circuit is operational, main jets only for higher engine speeds.
What size pilots are in yours?
Another source of info..
http://www.cb1.cun.net/Descargas.html

Its 20 years old now so probably not considered modern. I was having the problem at higher engine speeds. If im getting the pilot jet right they are all 35s. I have marked them in the attached pic

Flood

Have you inspected the carbs for wear in the needle jet, needle jet holder and jet needle?

Richard tea

Flood wrote: »

Have you inspected the carbs for wear in the needle jet, needle jet holder and jet needle?

Everything looked fine last time but sure Ill inspect them again just to be sure. When the new rubber carb boots arrive I dont plan on removing the carbs for a very very very long time.

Richard tea

Flood wrote: »

Have you inspected the carbs for wear in the needle jet, needle jet holder and jet needle?

Just checked and all are fine.


Turns out the carbs on theis CBR600 are the same as mine. And he includes this little gem

SKIP TO 3:15

CJhaughey

This era of bikes were setup for lean running I would look at richening the main jets to stock 105.
If the rest of your exhaust and intake is stock then it would make sense to run what was stock then.
Was this a California market bike? Mine was and it had really lean jetting from new in a different special CA only carb.
Most available info on the US market CB1 suggests to me that they were 105 main jet and 35 Pilot. If you really wanted to get it properly sorted a wideband air/fuel gauge would be the best thing or better still a dyno run.
Back when these were new dyno's were hard to find and wideband A/F gauges were very expensive.
Doing this could make the difference between a strong running bike and an OK running bike.

Richard tea

CJhaughey wrote: »

This era of bikes were setup for lean running I would look at richening the main jets to stock 105.
If the rest of your exhaust and intake is stock then it would make sense to run what was stock then.
Was this a California market bike? Mine was and it had really lean jetting from new in a different special CA only carb.
Most available info on the US market CB1 suggests to me that they were 105 main jet and 35 Pilot. If you really wanted to get it properly sorted a wideband air/fuel gauge would be the best thing or better still a dyno run.
Back when these were new dyno's were hard to find and wideband A/F gauges were very expensive.
Doing this could make the difference between a strong running bike and an OK running bike.

I havent a clue what market the bike was from. Ive put enough money into the bike to be honest so running OK will do. She ran pretty good before so im sure once i fit the new rubbers and cables it will be fine. I plan on selling in a year anyhow.

Flood

Richard tea wrote: »

Just checked and all are fine.

How did you check them?

cerastes

Richard tea wrote: »

I havent a clue what market the bike was from. Ive put enough money into the bike to be honest so running OK will do. She ran pretty good before so im sure once i fit the new rubbers and cables it will be fine. I plan on selling in a year anyhow.

How are you cleaning jets? I read before about special tools like pin punches for having through bores? As any thing else pushed through could damage and increase the jet hole size??

Where are you getting replacement orings, gaskets or cables?? The clip you show of the guy with the tip at 3.15 looks like the gasket are orings.are you putting new gaskets at the joints between mating faces to the cylinder heads? I'd read some of the thread so this may have come up as I didn't review the whole thing again since following.
Its the kind of thing I'd be interested to do,balancing carbs

Richard tea

Flood wrote: »

How did you check them?

Just by eye. I soaked them all in carb cleaner for 2 days. I then blasted them with compressed air. When I inspected them there is a perfect bore when held up to the light. Just in case you missed it, the carbs were working fine before I removed them so there shouldn't be a problem with jet cleanliness.

cerastes wrote: »

How are you cleaning jets? I read before about special tools like pin punches for having through bores? As any thing else pushed through could damage and increase the jet hole size??

Where are you getting replacement orings, gaskets or cables?? The clip you show of the guy with the tip at 3.15 looks like the gasket are orings.are you putting new gaskets at the joints between mating faces to the cylinder heads? I'd read some of the thread so this may have come up as I didn't review the whole thing again since following.
Its the kind of thing I'd be interested to do,balancing carbs

I dont have the special tool so just carb cleaner and compressed air. I bought the gaskets from here http://litetek.co/Carb_Kit_Honda_CB400_NC31.html

As for balancing carbs. It aint as straight forward as I thought. Special tools required depending on the bike and so on.

Richard tea

Could be the end of may before new rubber boots and throttle cables arrive. Any point in refitting the old parts until they arrive???

Flood

Richard tea wrote: »

Could be the end of may before new rubber boots and throttle cables arrive. Any point in refitting the old parts until they arrive???

I don't see why you have ordered both as it is easy to deduce if one or both are faulty/broken.

Richard tea

Flood wrote: »

I don't see why you have ordered both as it is easy to deduce if one or both are faulty/broken.

I needed both. The rubber boots are hardened and cracking. I be surprised if they lasted 6 month without totally failing. I needed throttle cables because one is splitting and the other has a slight kink.

Flood

I would not use those boots anyway, as for the cables I dont think they are part of your problem. All along are you trying to get a bike driving with hardened and cracking boots?

Richard tea

Flood wrote: »

I would not use those boots anyway, as for the cables I dont think they are part of your problem. All along are you trying to get a bike driving with hardened and cracking boots?

Just to recap. The bike was fine before I removed the carbs. Only on 2 or 3 occasions it died at high rpm. It seemed to be a fuel starvation problem. Ive checked petcock and vac etc etc. Removing the carbs was more of an interest than to fault find. Its looking like I put the jets back in incorrectly. I now know that the bigger jets go in the center 2 carbs and the smaller jets go to the outer carbs.

I done the test with the wd40 on the carb boots before and it did show a slight air leak. The bikes 20 years old so the boots could be that age also.

Flood

Richard tea wrote: »

I done the test with the wd40 on the carb boots before and it did show a slight air leak. The bikes 20 years old so the boots could be that age also.

Correct me if im wrong but haven't you put carbs back in bike already with old boots?

Richard tea

Flood wrote: »

Correct me if im wrong but haven't you put carbs back in bike already with old boots?

Ive had them out 3 times now. They are currently out of the bike. Honda have told me that some of the parts might not arrive until the end of May. Although im hoping they arrive within 2 weeks. I was debating on whether to refit the carbs with the old boots with the jets fitted correctly just to test it. But thinking of it now I think ill just wait till the new parts arrive.

Flood

Why didn't you order new boots the first time?

Richard tea

Flood wrote: »

Why didn't you order new boots the first time?

There was the slightest of air leak. In fact it would only fail the wd40 test on the odd occasion. Lets say for now the boots are ok. My point is they would need to be replaced in the near future anyway. I was not going to order one or three boots so I ordered the 8. You see flood there is method to my madness. I will hopefully sell the bike on in a year or there abouts. When I do I want to make sure its running well. Since I have owned the bike I had the fork seals replaced, New DID chain and sprockets fitted and the reg rec upgraded to a MOSFET type.

Flood

It would only fail the wd40 test on the odd occasion well thats makes everything ok, did you try the wd40 test doing x km an hour or just when its on its stand on neutral?
Have you a link to this wd40 test, what is a fail on a wd40 test?

Richard tea

So my shiny new throttle cables and carb boots arrived this morning. Big thanks to Lee Honda who took payment for the parts yesterday evening and it was delivered from cork this morning:)

I have re cleaned the carbs with brake cleaner and blasted them with high air pressure gun. All seals and springs etc etc are fine. Im going with the 2 bigger jets in the center carbs.

I fitted a new fuel hose from the tank to the carbs. I plan on fitting the carbs back into the bike tomorrow. Ill put fresh fuel into the tank also as whats in it now has sat there for a while now.

Fingers crossed it works out well tomorrow and I get the bike back on the road.

Richard tea

Ok so after a **** up with the throttle cables I finally got to reinstalling the carbs this morning. What have I screwd up this time you may ask. Well I fitted the carb bowls the wrong way so getting access the the drain screw is tight. This shouldn't even be possible but if there is a way to **** things up ill find it:o

The bike started fine and sound great. A small adjustment of the low idle is all thats needed I reckon. Unfortunately another problem has shown its ugly head. The 3 yellow wires coming from the stator overheated and one of them actually melted. I haven't a clue what has caused this. The wiring was fine when I fitted a mosfet type R/R over a year ago. I did spend time last week cleaning up electrical connections coming from the spark plug leads but this shouldn't have caused this problem. Im going to fit new wire and hopefully reuse the connection housing.

There is an earth wire going to the bike frame. I cleaned this last week and used electrical silicone around this earth connection. Could this be the culprit?

CJhaughey

Richard tea wrote: »

The bike started fine and sound great. A small adjustment of the low idle is all thats needed I reckon. Unfortunately another problem has shown its ugly head. The 3 yellow wires coming from the stator overheated and one of them actually melted. I haven't a clue what has caused this. The wiring was fine when I fitted a mosfet type R/R over a year ago.

Is there a connector between the R/R and the alternator?
If so check it for corrosion likewise the connector to the R/R make sure the terminals are all very shiny and clean, then use some dielectric or silicone grease to lube them as you refit.
Corrosion causes high resistance and can lead to the wires overheating or more commonly the connector plug between the Alt and R/R.

Richard tea

CJhaughey wrote: »

Is there a connector between the R/R and the alternator?
If so check it for corrosion likewise the connector to the R/R make sure the terminals are all very shiny and clean, then use some dielectric or silicone grease to lube them as you refit.
Corrosion causes high resistance and can lead to the wires overheating or more commonly the connector plug between the Alt and R/R.

Thanks CJ. Ill get at it tomorrow. I stripped the old wire out and fitted new wire. But it still overheated. Also the multimeter showed the battery wasn't charging. I bet one or more of my connections didnt hold. Its a pain in the arse but ill strip it off again tomorrow and double check connections.

Sorry I should have mentioned yes there is a connection between the r/r and the alt. This is where the wire first melted. Perhaps cause I had the side cover off for the last 8 weeks allowed moisture to get into the connection.

CJhaughey

Richard tea wrote: »

Thanks CJ. Ill get at it tomorrow. I stripped the old wire out and fitted new wire. But it still overheated. Also the multimeter showed the battery wasn't charging. I bet one or more of my connections didnt hold. Its a pain in the arse but ill strip it off again tomorrow and double check connections.

Sorry I should have mentioned yes there is a connection between the r/r and the alt. This is where the wire first melted. Perhaps cause I had the side cover off for the last 8 weeks allowed moisture to get into the connection.

If you can do it, remove that connector entirely. Go straight from Alt to R/R then direct to Battery.
The less the better when it comes to stuff in that system.