hard starting

[DGXSER]

Here is my thoughts. Initially, when they start hard but then easy when warmed up, it is a matter of not enough fuel when cold. On these bikes, that lends itself to the issue of the enrichment jet in the float bowl being clogged. However, that would not lead to wet plugs after just a few cranks typically. Just the opposite. So a little hard to point in that direction. But then again, if ti were my bike, I'd pull the carbs and check them and give it a try.

That leads my to think of the pick up coil wires, but those also tend not to go away from warming up.

As to timing being off, true that the cam alignment would not show up by checking the spark timing to the crank rotation ala a timing light. It would be VERY unusual for the timing to be off when cold and not when warmed up or lessen with RPMS. Not impossible, but not vary likely. Well...actually, it would not change, just might not be as noticeable perhaps.

Everything you have described would urge me to clean those bowls and jets, and verify the pilot jet sizes. Then set the mixture screws at about 2 turns out across the board. and re-install. See what you get from there.

[jeffro1954]

above 4,000 runs great. but idle is rough and the rpm's don't come down fast when coming off the throttle and most of the time when let up to shift rpm's goes up before settling down, so shifting takes some patience. Can't run it through the gears very fast. I haven't spent much time adjusting, carb synch was close but not perfect. I really need to check out if I've got gas leaking. petcock doesn't leak, but doesn't mean some of the extra gas isn't getting past needle valve and or floats aren't working right. Carbs have to come off for a general cleaning and see if that cleans up some of these problems.

saw something really neat today. 1973 Kawasaki 900 bored out to 1100 with a turbo charger!! He said it works great. Hasn't ridden it for a year, but wants to start it and put it up for sale. Very clean looking turbo set up.

[Tropic-al]

Hi jeffro.

Check that part of the old filter is not stuck in the channel where it sits in the case. When I removed what could have been the original, about a 1/4 inch thick piece of foam was left in the case. There was no way the case would close the way it should. Comparing the new and the old filter side by side, I noticed that top foam piece was missing from the old one. Scraped it off and voila, the case could now be closed. Hope this helps.

[QUOTE=jeffro1954;303168]Didn't touch the upper screws, seems as though either the new air filter is too tall but it's for a xs1100, or somehow what it screws into got wedged too high. Mine is far from a simple put back into place.

[soccer4m]

hard start

Jeffro,,,,sounds like you either have a lot of gas in the oil, again, easy check, just stick a long stick into the oil hole,get wet, pull out and sniff or light with a match,,,,if it burns easy you have gas in the oil, time to change the oil asap,,,,also with the slow drop in rpm's it could be a leak in the carb holders, spray some instant start or wd 40 around them while running and if any change in rpms if so, there is cracks in the holders, time to seal up, check the tech tips or buy a set............Mike in Sun DIego

[Jerry]

Don't overlook electrical issues. Make sure your cables are not corroded internally and that the grounding cable's frame connection is clean. The 'black box' is voltage sensative, so if there is much in the way of a voltage drop the bike will crank but not fire. Pull the battery and get it tested under load. Most battery places will do this free of charge.

I replaced the cables on my XJ a few years back and was surprised at how much easier colt starts were. Cut the old cable off near the battery connector, found corrosion between the wires. Replacing both cables cost about $20.00. Ground cable was from a local small engine repair shop that had the right length in stock. Positive cable was a Yamaha OEM through the dealer, cost was around $13.00 or so.

Plugs can look fine but have a high internal resistance. Same with plug caps. If you don't know the history of both, replace with new plugs and caps.

Carb issues are most likely, but not only cause of hard starting. If you think you have your carbs sorted out, start looking at electrical issues. Replacement of cables, plugs, and caps is a good idea just for routine maintenance and doesn't cost all that much.

[jeffro1954]

hard starting update

here is my update. took the carbs off, did cleaning, checked float height, but didn't rebuild the carbs with new parts. tried to do my best with the spooge hole. tested it off the bike, no overflow to the air box or motor. Nice and tight. put it back on. same thing, have spark, plugs get pretty wet after a few turns but won't start. With starter fluid it started right off. still runs rough at lower rpm's, I need to adjust idle and check synch.

Maybe the carbs need a full rebuild this winter, I bought these from someone who SAID he rebuilt them but who knows if he did or how well. I know the bowl gaskets were not replaced so he may have just done a cleaning and put it back together.

Any other suggestions? or the symptoms sound familiar to anyone?

[CatatonicBug]

I have "rebuilt" my carbs at least 5-6 times, but never replaced the bowl gaskets, so that doesn't necessarily mean anything.

I would suggest spending an afternoon and completely tear them apart (you probably don't need to separate them from the rack though) and remove all the jets (air jets too) and especially check the choke/starting circuit. The tiny holes in there can get clogged and really mess with things. 2 cans of carb cleaner spray, and about 4 hours of casual tinkering should be all you need to get it clean as a whistle. Of course, a good sync makes a world of difference too.

[DGXSER]

Have you verified the jets and their sizes? Looked at the pilot jets to be sure they are the BS30/96 with 6 holes in the sides?

Some people have found that the aftermarket jets are nto sized the same. Also, if you have the wrong pilot jets they can be screwing up the mix.

[jeffro1954]

I think I'm resigned to rebuilding the carbs over the winter sometime. I'm in Minnesota and we're expecting 6" of snow Saturday so I might have to put the bike away until next year. The bike doesn't miss a beat above 3,500 below that and at idle just not great and the rpm's still don't come down very quickly. I found 2 more 78 1100's ($300 for the pair) that need some help, wish I had more garage space and a wife that agreed working on the bikes would be a good hobby!!!