Hard to start, when warm revs climb?

[walleye]

Hello folks.
Having trouble starting my xs400 4g5.
Running pod filters so went up two sizes on pilot jets and main jets. 47.5 pilots and 130 mains.
Once the bike is running it goes fine through all rev ranges but idle climbs once its hot.
Bike fires initially on enrichener but then dies and is difficult to start, when it does it is because I open the throttle stop a couple of turns and start it without enrichener.
Have I gone to high on the pilot jets?
Air screw is set at 3.5, have opened them up to 4.5 but still get the same effect
New carb boots but haven't tested for leaks and haven't checked the valve clearances yet.
Should I try the stock 42.5 pilots as a first thing?

 

[Scorpio1963]

The jetting guide only recomends going up 1 size,not sure if that's whats causing your problems or not but it could be.Also what kinda pods do you have please don't tell me those cheap silver screen cone type cause that could be your problem also if you have them hooked directly to the carbs.Those type of filters cause blockage to the jets.

 

[Yamaguy55]

Valves should always be set before carb tuning. Same for timing if you have points.
The mixture screws aren't set to a specific place, but rather adjusted after carb sync to provide the best idle with the throttle plates as closed as you can get them.
Start by putting the original jets back in. Do the valves and be sure the plugs and wires are good.
If you need to take the "choke" off right away, I'd say you're running rich.

Idle mixture: the pilot jets meter the fuel supplied to the mix. The now mixed fuel/air is then supplied to the screws at the top front. After the throttle plates are synced, they are closed as much as possible, and you go back and forth between screws and throttle stop until it runs as clean as possible. Since four strokes don't do well with excessive richness, after this, turn in mixture screws about another 1/8 th turn each, that makes them just lean enough to be sure you're not too rich at idle. Those screws are allowing already mixed fuel/air to bypass the throttle plates and set the mix for the idle. You want it just slightly lean of where it runs the fastest, which will vary by bike and with temp and altitude, humidity, etc. so the cold weather settings will usually be slightly richer than settings for hottest part of summer. Cold air is denser and holds more oxygen per gallon, so it needs more fuel.

 

[walleye]

Thanks for the fast replies guys!
I'll try the stock 42.5 pilots and let you know how it goes!

 

[Yamaguy55]

Be sure yor carbs aren't clogged up. Common problem on these.