Have you tried holding the throttle wide open while kicking to get some air in there... Yeah, they can be a pain sometimes. Could be boiling the fuel after a hot run. I'd think a lot of the cylinder heat is transferred directly to the carbs but shielding can't hurt if you don't block air flow around the cooling fins.

Question
Mine being a 600E electric start only starts on the button hot or cold no trouble, did Yamaha reduce the compression ratio for the electric start models and is there any difference in performance between the eariler non-electric and my bike? I do recall my years ago looking at a 500SR which required a certain knack to get it started.

I used to poo poo the electric start models, not so any more even with the increased weight and complexity. Oh well, I'll just keep on kicking til I kick the bucket....:clap::clap:

I have tried everything to get mine started hot. Hold throttle wide open, hold half open, hold just a little bit, full choke, half choke, full choke/partial throttle. It never even pops or spits, only a loud bang from the exhaust sometimes on the very first kick, then nothing.

Now yesterday I put an aluminum plate between the primary carb and the motor, I didn't have as big a plate as I wanted but this one is about 2.5inches down and 3.5 long, I'll make one here at work that sticks down maybe 4 inches and 5 inches long so it covers both carbs completely. Anyway, last night I ran an errand and it did start up after sitting about 6-7minutes so maybe it is working. I'll try again tonight when I get home, I'll try to restart it after 7-8minutes. Fingers crossed, it'll be nice to actually fill it up at the gas station and not sit on the curb for 10minutes waiting for it to cool down.

That would be good news indeed....!!!!:thumbup1::thumbup1:

Did it again tonight-twice. Started up first kick with just a little bit of throttle!
So it seems the heat from the engine is playing havoc with the fuel in the carb. I believe the high heat is evaporating it and causing too much vapor, which puts the fuel/air mixture to the point that it won't ignite(unless some gets into the exhaust and has enough O2, thus BANG). Letting it cool allows the extra vapor to dissipate and you start over with a "cold start".

There you go !!

can you share a picture of your "FIX" even if crude so we get the idea of what worked....

Here's my temporary one till I make a better looking one and hopefully anodize some design on it. Started up again tonight no problem.

Seem strange to me that you have to make this for the bike to run, if this was a real problem everyone would have same problem..I never had any problem with this and i have had with kickstart and electric, same year as yours and 93mod.

Every bike is different. It isn't to make it run, it's to make it start easier when restarting the motor when hot. This issue is the reason why so many modern bikes have hot start buttons.

It was a common issue with these and the 550. On ebay there is a company that makes a plate for them, I don't know of they woron the 600.

Looks good. I will try one myself....