1971 Kawasaki A7 Avenger

**Mike.Gayner** · 13th December 2013, 15:55

Plug RHS: http://i.imgur.com/G48Dier.jpg
Under flash, trying to get the whole insulator: http://i.imgur.com/mbWAKU5.jpg

Will take out the LHS this weekend - just wanted to get back on the bike. I'm actually now convincing myself that the right side is OK and the left side is cool - after a few mins of riding I could feel heat off the right side from a couple of inches, left side felt cool from that distance.

edit: BTW in person the plug looks more like the first pic than the second - the flash makes it look whiter than it is.

**eelracing** · 13th December 2013, 19:57

Originally Posted by Mike.Gayner

Plug RHS:
Under flash, trying to get the whole insulator:

Will take out the LHS this weekend - just wanted to get back on the bike. I'm actually now convincing myself that the right side is OK and the left side is cool - after a few mins of riding I could feel heat off the right side from a couple of inches, left side felt cool from that distance.

edit: BTW in person the plug looks more like the first pic than the second - the flash makes it look whiter than it is.

That plug is pretty new eh Mike?It's not dirtied up enough for a decent reading.But going on that first pic It looks fine.(post up a pic of both plugs if poss)

First thing first tho you've got to balance the carbs and check the oil pump settings,hopefully explained in your manual.And a visual check that the oil is coming through the lines.The RHS maybe running at optimum and the left side simply overfuelling...always pay's to check and then check again.

Do that then a compression check and it's plug-chop time.

Another thing to take into account is that the fuel we use today is shit compared to what was used back when these bikes were manufactured and almost always invariably means jetting down.

**roogazza** · 14th December 2013, 06:29

I have a better idea Eel, you buy it and i buy your LC ???????

**Mike.Gayner** · 14th December 2013, 08:03

Appreciate all the help guys. Here are the plugs (left and right respectively):

http://i.imgur.com/HGKZuOS.jpg

edit: And yes Eel both plugs are quite new. Maybe I need a few more miles on them before I can get anything useful from them.

**Mike.Gayner** · 14th December 2013, 08:15

This is the page in my book that deals with checking the condition of the oil system. Can anyone shed any light on this for me? Thanks.

http://i.imgur.com/2Ev06PR.jpg

**roogazza** · 14th December 2013, 10:58

Originally Posted by Mike.Gayner

Appreciate all the help guys. Here are the plugs (left and right respectively):

http://i.imgur.com/HGKZuOS.jpg

edit: And yes Eel both plugs are quite new. Maybe I need a few more miles on them before I can get anything useful from them.

Geez mike ! Something well out there if those plugs were fitted new at the same time ?
Left on the photo, means the left on the bike while sitting on the bike right ?(just to be sure cos some don't know that !)
Either the left is not working hardly at all and lean or the right is not and is fouled ???
Pull a lead off while it's idling, it'll either stop or stay the same I'm guessing ? Looks like it maybe running on one !!!!!!
Whatever it's miles out.

**Mike.Gayner** · 14th December 2013, 12:53

Thanks roog, yeah left = left on the bike, and it's dawning on me that the issue probably lies more in the left side than the right. I took it out for a longer ride today (despite everyone's advice, oops) and the bike performed well, though was low on power. I don't think it's running on one, but I think the left side is performing poorly, so I need to figure out why. Yes they were put in new at the same time. Here are the plugs after about 40km of riding today: http://i.imgur.com/7rYqedb.jpg (left in the photo = left on the bike)

Obviously I have some work to do...

**Mike.Gayner** · 14th December 2013, 14:00

I'm such a retard. I thought my quick clean of the carbs when I first got the bike was sufficient, but evidently not. I took the left carb off and the main jet was completely clogged with old varnish. Cleaned it up and I'll take it for a ride shortly, or perhaps tomorrow.

All this time fretting over the right side, and the left is where my real issues lay. Being the main jet also explains why my efforts to diagnose at idle were wasted.

**Mike.Gayner** · 14th December 2013, 14:51

Mother of god I can't believe what a difference that has made. Everything I thought I knew about the performance of this bike was wrong - basically until today I've been running it on 1 cyl. Keep in mind that I have no frame of reference - I had no idea how fast it was supposed to be, and the only other bikes I've ridden were 250cc singles. So when the performance of this thing was a little more than the 250, I thought that was right. But after clearing that main jet, this bike is so much faster than I thought. What a blast.

I'm so happy to have fixed this performance issue - even though it was something so stupid. I'll take it for a good long ride tomorrow and pull the plugs again - I might get a mate of mine to chop them and give me a detailed analysis after a few more km's.

**roogazza** · 14th December 2013, 17:00

well done, don't how you missed running on one,but hey, glad you're on track now.
You have me all enthused too !

**eelracing** · 14th December 2013, 18:12

See,simple eh mate.Every clue was there all the time,congrats for working through it and figuring it out.
But remember all carby jetting starts at the mainjet,It will influence where you will set idle and mid range etc.

On your long ride tomorrow (coz let's face it,nothing is gonna keep you from it)take regular stops and check the plugs and if your happy then find a nice long stretch of empty road.Get her in an upper gear (4th or 5th) and wind her right out to full throttle and hold it there at full open for 5 to 6 seconds.You should be at or near the redline. (it sounds harsh but a well fuelled smoker loves it)After 6 seconds pull in the clutch and hit the engine kill switch simultaneously and coast down to a stop.Don't be tempted to just whip in the clutch and slow down with the engine running as it will give you a false reading.Now you want to check the sparkplugs as this will tell you how she fuels at full throttle.Take a pic as well for reference.
And congrats you've done a plug-chop (bugger ya mate,he can get his own bike).

That oil pump diagram seem ok to follow...the actual pump meterer is the half-moon shaped pulley at the bottom.This should move in conjunction with the throttle and I'm presuming the arrow head shaped pointer should line up with some marks on the pump body at idle and full throttle.

**Mike.Gayner** · 15th December 2013, 12:32

The bike ran magnificently for a ride of about 50km today. The plugs don't tell me much, having started from such a different state to one another, but here they are anyway: http://i.imgur.com/0dqrfOu.jpg

So looking a lot better, but I'll have a better idea after I put in new plugs and do a chop next weekend.

**SPman** · 15th December 2013, 13:19

Originally Posted by pete-blen

Yer might be thinking of the Avon Roadrunner..

I use to use Dunlop K91 red arrow on my Kawasaki 400 S3 triple were next step up from the K81 TT100...

Red Arrows - they were meant to be the next big thing after the TT100's - I ran a set on the Ducati GT750 - couldn't really tell any difference......

**roogazza** · 15th December 2013, 15:12

Originally Posted by Mike.Gayner

The bike ran magnificently for a ride of about 50km today. The plugs don't tell me much, having started from such a different state to one another, but here they are anyway: http://i.imgur.com/0dqrfOu.jpg

So looking a lot better, but I'll have a better idea after I put in new plugs and do a chop next weekend.

Don't forget to look well ahead when you are doing the plug chop ! I can see it now.There's bound to be a cop at the end of the road with a laser.