Got it running but got some problems

[Robbo]

I finally got my beauty running this weekend - what a treat.

There are a few bits that need adjusting and I thought I would put it out here to see what you guys advise.

Carb 1+4 spit back sometimes, Carb 1+4 leak petrol through the jets that point to the filter, Downpipes 2+3 are hot, whilst 1+4 are lukewarm.

I'm sort of guessing the floats need adjustment as the fuel begins to spill from the jets as soon after the fuel has been turned on, not quite sure about the spitting(backfiring?) but again this might have something to do with over fuelling perhaps? What I really don't have clue about it the difference in downpipe temp.

Any advice or info would be very helpful.

[LesterPiglet]

Yep, check those carbs and clean them. 1 and 4 use the same coil/points so check those areas. 1 and 4 are colder cos they aren't firing properly due to the point/coil...possibly carb problem.

[K2-K6]

I'd go with floats and needle valve first as well.

If you turn the fuel on until it just starts to leak then turn it OFF again it should then run reasonably well if it's just the fuel overfilling (they would run to about 5 miles with fuel off with those carbs). Should allow you to verify if it's just the carbs (float operation) doing it if the running cleans up.

[UK Pete]

The press in pilot jets in these carbs are really prone to blockage causing low running problems , i would take the carbs off and apart, cleaning everything , also the accelerator pump jets and diaphram can cause problems in a bike that has sat about a few years
pete

[Robbo]

How do I get the press in pilot jets out? I had a look before but I thought they were fixed?
I have had them apart and sprayed carb cleaner through all jets until they were clear. I'm getting pretty good at removing and replacing these carbs now!
How do I know if the pump is working and how do I fix it if it isn't?

[UK Pete]

There are many things that go wrong with the pump, the rubber diaphram split or perished, the ball bearing pump valves get seized, the spray nozzels blocked, best thing is to have the carbs off and upright with fuel in the bowls, then open the throttle mechanism and see if it is squirting from the jets, there is loads of info on sohc/4 site and here http://www.hondachopper.com/garage/carb_info/accelpump_valve_repair/page9.html
The jets are a push fit you protect them with a bit of leather just grab pull and twist them with a pair of grips and they shoul come out
hope this helps
pete

[Robbo]

Thanks Pete, you're a gent

[UKROBK7]

If there is fuel coming out like that I would look at the float needle valves and then float height but I would have thought that fuel would be seen coming down the overflow pipes.  (1 of my carbs, however, was "fixed" by a previous owner by raising the internal overflow tube with a piece of plastic sleeve making the tube about an extra 10mm high instead of changing the badly scored needle)

Just rebuilt my k7 carbs and pulled the slow jets by locally heating the bodies using a hot air gun (the small one for heat shrink tubing) but they still needed a lot of force to get 2 of them out.  Glad I did, 1 of them had completely blocked side holes and another had them partially blocked.

I also found my accelerator pump ball valves were corroded and I replaced those with stainless plus a new diaphragm, now the valves work as they should.

Rob

[Robbo]

I had the carbs apart last night in my workshop:

The BB and spring on the accelerator pump were missing, I made a handy replacement with the end of a pop rivet and a home made spring - it works a treat!

I pulled the pilot jets out and gave them a good clean - there was so much s**t in there that I used a 1mm drill bit to clear the main hole out.

Set all the float heights - hopefully they won't leak anymore (but I will hook them up to a tank to check before I put them back on the bike)

I'll let you know how I get on this weekend