TROUBLE SHOOTING HELP PLEASE

:? I have a 1982 XJ 750 here in Thailand that I have had for over 4 years now, problem is that at low speed it wants to miss sometimes (but not always), at high speeds I have no problems.

Another problem: When bike is cold it starts easy, but if it has been riden for say 20 mins and you let it sit for more than 5 mins, then it is hard to start, however if it gets cold again it starts right up or if you only shut it down long enough to get gas then it will start right back up?????

I am now cleaning the carbs out just to see if that could be the problem, however I am leaning towards one of the coils being weak and at low rpms maybe it cannot produce enough spark all the time but at higher rpms it 's great. Maybe when the coils get hot they are breaking down and that's why if I only shut it down for gas it will start back up easily however if I let it sit for 5 mins while it's going through a cool down period it doesn't want to start.

Now it will always start but it has to turn over and over of which is embarrasing as others are always looking and of course it always does it where there are many people looking both because I'm a foreigner and it's a big beautiful bike here in Thailand...

Any help would be appreciated...

In addition I would love to get ahold of a set of the XJ CD's everyone talks about. I have no credit card and I'm an old Retired Marine living here in Thailand. I can however send money through Western Union if I can get someone on your end to send me the CD's.

Thanks in advance.

KHUNDAN

 

Thanks SnoSherriff for the input. I will wait for the new cd's to be released before I order. Hopefully someone will be able to help me out with this troble shooting bit.

KHUNDAN

 

Another heat related issue is the valves... do you remember when they were last adjusted?

If it were a simple electrical issue it would be easier to start the bike when it was warm than cold... when cold you typically have to crank it a bit longer and tend to need a bit better spark to get it to fire up... if you only had a weak spark then you'd think it would be easier to start when warm.

For a check of the carbs - start by looking at the color of your plugs? Perhaps you're on the lean side ( white to very pale tan) good is tan to brown and rich is dark dark brown to black and sometimes oily looking.

What are you doing with the choke? Are you using it even on warm starts? Just checking on that one.

I think you've started with the carbs which isn't a bad thing to do - they look clean you say - how about the tiny little passages? If you use some really really soft copper wire you can CAREFULLY clean them out... hardwire will damage your carbs. The small passages of the carbs get plugged the fastest and are the most effected by dirt and varnish.

keep digging,
woot.

( Waiting for the big dogs)

 

i'd tend to agree with woot,i would be looking at timing related things,valves timing chain? etc. sorry not up to total speed with the little brother xj's mine has a cam chain and adjustable valves (shims) that do require rutine maintenance to run proper.

 

The 650 Maxim has shim under buckets - I'd suspect the same for the 750. It's not a big deal to check, however, it is a pain finding new shims.

There is a shim pool with the micapeak mailing list... or do what I've done in the past and pay a shop to do it.

 

Well, I took the carbs off again and took my time cleaning them and yep I found some small particles in the bowl and it some little places so I blew them out cleaned them out.

Put the carbs back togther and went for a 250KM ride yesterday. No problems at al even on the starting etc..I am hoping this got it worked out. I did get a pop at about 95 kph once sort of like a backfire but then it ran even better maybe something I missed in the carbs.

Hardly ever use the choke, matter of fact I dont even have a choke cable on the bike. Holder broke about two years ago and never replaced it. It's always warm here in Thailand.

Thanks for the feedback and I'll let you all know if it didn't fix the problem after a few days riding.

Have the Bike week in Pattaya next month and I will be riding with 2 clubs here to the event about 6 hour ride one way at 110kph.

KHUNDAN

 

Want to keep the porblem from coming back? Add an inline fuel filter.

 

BLUE MAXIUM, Thanks and I finally got the common sense to do this a couple of days ago. Always thought about it but never did it.


KHUNDAN