Air leak on carbs 1983

[ScottyShy]

I recently replaced the rubber boots that connect my carbs to the engine, and i also replaced the clamps that tighten them down. Somehow i'm still getting an air leak on my left side. My bike is kick start only with a Boyer ignition and a hugh's PMA rec/reg.. Sometimes when i kick start the bike it kicks back on me, and i can hear air pushing backwards through my carbs. The other day it kicked back so hard that my left carb popped out of the boot! That's when i replaced the clamps bc i thought that might be the issue...

I know there's air leaking on the left side bc i tried the trick where you spray carb cleaner at the boot. The RPM's go up when i spray the left side.

I'm guessing there could be a number of issues related to this, but i thought i'd seek some advice before diving in..

When i got the bike a year and a half ago, i had the compression tested, and I know that it's low on both sides. Not sure how that may affect this problem..

 

[angus67]

After the. Ike is warmed up, you can usually get those clamps a little tighter
Sounds like your timing is off

 

[vincejames]

Take a look at what I outlined in red (attached) make sure that that gasket is not loose. Use your finger to see if it is loose. Make sure that you cannot see any light coming through.

I agree, timing is probably off. Check out the tech section on this forum

 

[grizld1]

Scotty, I once fought an air leak between boot and head for a week before I figured out that a PO had cranked down so hard on the screws that tops of the holes had become extruded high enough to prevent a seal. A few strokes with a flat file (one that really was flat, most of them aren't) was the cure.

+1 re. Angus' advice on timing. First off make sure that your timing marks are on the money with a piston stop and degree wheel. To get accurate results, record the crank location in degrees at equal piston drops on either side of TDC. True TDC will be at the midpoint of those readings.

 

[angus67]

I didn't elaborate because i dont know that system but i do know my 71 kicks back like mule when i was trying to awaken it from its 20 year slumber.

 

[ScottyShy]

I'm going to keep searching for the air leak.

My bike will start up and idles really well. Its when i'm accelerating that i feel a loss of power. It was running a little better about 3 weeks ago, but it seems like its gotten worse. I think it's a mixture of low compression in my cylinders and now this air leak at the carbs.

FoooF!!