1982 430xc Hot Start Issue

Hi everyone. I have a hot start issue with my '82 430XC that I would really appreciate some advice on. During a race, if the bike stalls, it is really hard to get it to re-start. I usually have to choke it, then quickly remove the choke when it starts. I don't think this is a carb issue. The bike runs good, plug looks good, and it starts well when cold. I suspect it might be an electrical issue. Coils sometimes act up when they get hot. The bike has very low miles, and the only modification is an FMF Turbine Core 2 silencer. Thanks for your help.

has it always done this or is it new? mind posting your jetting you are running?
there is a chance the motoplat coil or stator are starting to get weak.

The bike only has about 300 miles on it. I didn't notice this until I ran it hard in a couple of hot weather cross country races. Jetting: 410 main, 45 pilot, 6DH3 needle 3rd notch from top, 2.0 slide. I'm at 500' elevation.

the fact you need to choke it suggests its a bit lean on the low circuit? i would strip the carb and give it a real good clean out especially the idle and pilot circuits. check your slide for wear and the cap rubber for seal and the inlet manifold for splits. i would also pull the maggy cover and check for any fuel residue due to a crook engine seal. other than that its an electrical issue...

I agree with surprise , seen the same issue on a couple 430s. Just real simple clogged idle jet thatn after hot
would no allow hot strating and even stalling. Now this sounds crazy that the pilot did this. but true
Start simple with this, then I would check grounding on all the bolts , like engine mounts, coil mounts etc lets check the
simple stuff first.

Great advice guys! I will check everything you recommended. Thanks

FYI my 82 430 XC runs this jetting and is relatively good to start hot or cold. It has the mini 6 motoplat which has a weakish spark (need to have garage doors closed to see the spark!)

400 main jet, 20 pilot jet, R4 needle jet, 6DH3 on top clip,

Running 3 percent oil ratio.

I am at 250 feet but ride at 500 ft no problem.

Good luck

Thanks PEZBerg. Good information. What size pilot jet?

I've had the same problem on my 240 wr 82 when it was hot .
Kicking 10 times with no effect.
Older bikers only told me to kick it with full throttle and it works.
Full throttle when kicking is like to make richer.

the pilot was 20...it was hiding behind the main jet. i always give a tad of throttle to a hot start on the 400 but it will also start with no throttle and idle happily away...

Thank you Michel.

Unless you have one of those UFO s on the slide , your pilot jet is to small. lets try 40 45 pilot to start , that 20 is the reduced size of pilot for a UFO custom plastic block that is screwed in the bottom of slide to make air flow more intense. Start with 45 !!

Your starting is starved for gas

The only jet that has that number in a carb is a very tiny air jet in the rear bell housing
and its a 2.0 not 20

Thanks for clearing this up Gary. Sounds like my 45 pilot should be close.

I ran into this problem of a good starting 81 430 XC and as the year went on it needed more throttle to start hot.. Was a very bad warped reed pedal which caused a lean condition.. Naturally on cold start I was using the choke as well so it lite up great as normal

Thanks Carl. I had not considered a reed issue. Great thought.

Something to consider that no one has mentioned is to make sure the float level is correct. Could possibly to low.

Marty

Thanks Marty. I checked the float level and it looks good. Also, plug shows it's not running lean.
One "smoking gun" I found was a corroded spark plug cap that also had a weak connection to the plug wire. I cut off 1/4" of the plug wire and installed a new "screw-in" plug cap ... NGK LZFH non-resistor. I really believe this was a problem. As PEZBerg stated, these bikes produce a fairly weak spark. And, when the wiring heats up during a race, less electrical current is transported to the spark plug. I have cleaned the carb thoroughly and checked everything you guys suggested. I bet the issue is resolved, however I have not had an opportunity to run the bike hard. Time will tell. Thanks again to everyone for your help!

good luck!