My kawasaki 650 seems to be not runninig on all four carburaters, i checked for spark and it reads ok, also, the other three header pipes are very hot and my left outside pipe is barley even warm, can you give me any clues? thanks . [email protected]

Looks like 0.7mm which seems far too narrow to me!

https://bikerrated.com/gear/maintenance/kawasaki-spark-plug-fitment-chart/

GPZ 900 Service Manual doesn't mention it

https://www.manualslib.com/manual/1425138/Kawasaki-Zx900-A-Gpz900r-1984.html?page=25#manual

650 is .032 (32 thou) or 0.9mm

https://www.manualslib.com/manual/824343/Kawasaki-Ninja-650.html?page=110

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Here's the link and I'm sure you will get the solution of your problem.

https://www.reliable-store.com/products/kawasaki-fh451v-fh500v-fh531v-fh541v-fh580v-fh601v-fh641v-fh661v-fh680v-fh721v-4-stroke-air-cooled-v-twin-gasoline-engine-service-repair-manual-instant-download

A hotter plug could cause the piston crown to melt (depending on how much hotter) The reason engine makers give a recommended spark plug is because this grade will give the best performance and efficiency. Try reverting to the correct grade.But the headers glowing red is not unusual as not all header pipes are twin wall tubing.

It sounds like something may have shorted, come loose, or burned out.
Tracing where this is will take time and a multimeter to test all connections.

No, it is more likely a bent exhaust valve or burned. The fuel flow position may indicate an additional issue with the carb, but the exhaust should not glow red like that- when it does it means there is unburned fuel and burning combustion gasses entering the pipe.

If the bike is hard to start, this can be why as well. Do a static compression test to see if the valves are leaking.

If the ignition is producing a good spark at the plugs and the mixture is correct it may require re tuning due to the exhaust pipes giving a different back pressure reading to the engine.
Fit the old pipes and see if that fixes it, if it does, there's your fault. If not something has happened like a wire is off/broken/earthed out.

Hope that helps.

Sounds like you have some dirty carburators, if the bike has been sitting likely your carbs are all gummed up, they should be removed and properly cleaned.

Hi there,
You will need to do some diagnosing of the problem. Some things to check

• compression check across all cylinders. Low compression(less than 100 lbs in a cylinder will prevent it from firing. They should all be with 20 pounds of each other.
• carby to that cylinder may have a clogged air passage or jet.
• try a new plug in that cylinder.
• check for air leaks about the problem cylinder air intake. Use aerosol carb cleaner to spray about the manifold gaskets and carb mount. The revs will change if there is an air leak.

MOst probably you will need to strip and clean down the carbs if you have good compression and spark. Fuel is the only thing left :) Sometimes running some fuel system cleaner additive will also resolve the issue for you without tearing down the carbies. Goodluck regards robotek

Hi, the pipe getting red at the header is caused by the fuel mixture being to lean or the ignition timing being too retarded. Check the induction side of the engine for air leaks and the carburettor for blockages etc. Check the ignition timing.
Hope that helps Matt...

first lay out all your exhaust system parts . take inventory.2 ex. gskt.2 mffler gskt,left muffler(short),right muffler(long), header pipe,4 collars, 4 nuts(6 mm),2 holders,2 muffler clamp,2 hanger bolt,2 nut( 10 mm). next. put small dab of grease on exhaust donut gaskets so they will stay in place by themselves when you stick them in place in the exhaust ports ,on the cyl. head.next gather collars, head pipe w/ holders & 6mm nuts, w / 10mm .wrench or socket.tricky part,hold head pipe up in plce to head,take collars w/ lip or bend facing out & put in between pipe holders & ex. donut gaskets,place holders over exhaust studs & install 6 mm nuts & tighten evenly but do not tighten all the way just keeping collars in place. now hang mufflers,w/ gaskets,clamps,nuts, & bolts,loosely.now tghten down head pipe evenly,cheking collars for proper alignment as you tighten.next,tighten mufflers to headpipe w/ clamps using 12 mm socket or wrench.next, tighten mufflers to frame using 14 mm.finally, start bike & check for exhaust leaks.