Topic: 73 CB350F, CO & carb problems

[rboe]

Reset the air screws, sync'd the carbs then tossed on the CO tester.

First problem, with test gas tank hanging up, too much head and all four carb overflows gushed gas. Lowering the tank helped, number four only leaked, and just a wee bit.

Got sniffer working (long warmup period) and the left pipes were at about 5.5 to 5.7 where the two right pipes measured out at 3,5 ish. Tweaking the air screws did not seem to make much difference. As I scratch my head I'm looking at putting in new plugs (grasping at straws). But at least the numbers are better than what the emissions station gave me, assuming me test gear and theirs are accurate.

[rboe]

Did a compression test, engine was warm but not hot. Full throttle, cranked until the needle settled on 130PSI, even on all four cylinders.

Seems kinda low to me, would engine Hot be better? Only 8000 miles on the old gal, sat for 28 years or so.

[harisuluv]

Yes warmed up engine will give higher compression than a cold engine.  Have you done an all around tune-up on the bike?  Points, plugs, etc.

[rboe]

Have not. Bought a Dyna S, but have to installed it yet. May get to now!

[tomkimberly]

Change the oil too if you haven't.

Tom

[rboe]

Oil is new Honda syn blend, runs very nicely with it.

Did an extremely bone headed move yesterday, neglected to reinstall the nut and bolt that hild the spark advance on. It let loose at about 5K rpm and broke off half of the dyna s sensor package. New one order.

It did seem to run just ever so little, a wee bit better, so I may be on the correct path - be it ever so expensive.

[rboe]

Pulled the carbs today (again - I'm beginning to really hate throttle cables) and found the floats all over the place. Taking a hint I learned on another thread here looking for something else I set them to 24mm. Dropped out the emulsion tubes and plugged one end while shooting carb cleaner through them (what a pretty mess!  ). Reassembled. Sync'd the carbs then ran the CO tester again.

I got very good numbers and the motor seemed to run stronger (Dyna S was installed) so I took it for a test ride. Oh man, she rides a lot nicer. Does not need nearly as much throttle as earlier test rides, more torque down low (still not much but better than before) as was able to run her up to 60mph).

Burning Chevron regular this time too.

I'm going to run her through emissions this week and see what the the machine there says about my tuning skills. 

[fmctm1sw]

Do you have your own sniffer/gas analyzer?

[rboe]

Yes sir. Picked one a couple weeks ago, Gunson. $230 bucks, not cheap but it keeps me from shooting in the dark and making a potential trip after trip to emissions. It's nice to have some numbers showing you are on the right track while adjusting these things.

[rboe]

Bike was running good, took it to emissions and she was puking gas from the float bowls and got kicked out. Got home and pulled the hoses out, I can see they are wet but they were not dripping. What the hell?

I'll have more time tomorrow to check it out. The float valves are new but the seats are not. Is there a way to dress the seats ro replace them?

[fmctm1sw]

Yes sir. Picked one a couple weeks ago, Gunson. $230 bucks, not cheap but it keeps me from shooting in the dark and making a potential trip after trip to emissions. It's nice to have some numbers showing you are on the right track while adjusting these things.

If you had it smogged again it would be interesting to note the difference between that Gunson and the 4 or 5 gas analyzer's CO reading.

[rboe]

Indeed!

I'm waiting for new floats to show uo now. Pretty sure the old ones are not floating like they should.