[SOLVED]Engine break-in....stalling...overheating?

ELCouz wrote: ...bike perform like a champ until i go to idle for prolonged time (ex:red lights, stops)!....

A classic example of too tight valve clearance.

Insufficient compression due to valve leakage when warm prevents suction of mixture from carb.

Acceptable compression test figures are not enough.
Correct valve lash is essential.

Would assure all valve clearances are within specs.

Good Fortune!

A classic example of too tight valve clearance.

Insufficient compression due to valve leakage when warm prevents suction of mixture from carb.

Acceptable compression test figures are not enough.
Correct valve lash is essential.

Would assure all valve clearances are within specs.

Good Fortune!

I know you are trying to help Patton but you sound like an automated forum message...

Clearance has been checked 5 times (yes 5 times)!!



If you want the result i can copy them from the first page... here we go!

EDIT: full valve recheck

Exhaust valves:
#1 0.13mm
#2 0.12mm
#3 0.13mm
#4 0.10mm

Intake valves:
#5 0.17mm
#6 0.17mm
#7 0.16mm
#8 0.14mm

There is enough valve lash on the intake valve ... i can hear it too

regards,
laurent

EDIT: i know there is a lot of problems on this forum related to valve clearance...but i really do check my manual completely (FSM) before posting here, using the forum as my last resort thing ( posting annoying recurrent easy problems is the last thing you would want to post on a forum) RTFM would they say

Have you got a Mikuni fuel pump laying around from a sled? Like this, www.motorcycle-superstore.com/4/22/423/2...1&zmac=45&zmap=22375
You could positive feed your carbs and try it. Although the needle and seat would be smaller for a set of carbs with a fuel pump, it would be worth a quick try and see what happens. This is if you really think starvation is your problem, it should make sure the bowls stay at the level you have set.

Have you got a Mikuni fuel pump laying around from a sled? Like this, www.motorcycle-superstore.com/4/22/423/2...ac=45&zmap=22375
You could positive feed your carbs and try it. Although the needle and seat would be smaller for a set of carbs with a fuel pump, it would be worth a quick try and see what happens. This is if you really think starvation is your problem, it should make sure the bowls stay at the level you have set.

That would be overkill...would induce pressure to the carb fuel intake overflow them ? (after all float needle is easy to push!)

Some people complain about the lack of power from this pump...

I went the fuel pump route. BTW the DF44-211 lacks the capacity to keep up with hard acceleration, at least on my open airbox, DJ kit, Staintune piped DR650. The DF52-73 works fine - just blocked off one of the outlet tubes.

How could connect the pump ? From the oil breather ? Would that prevent escaping the fumes or water vapor from the crankcase?

regards,
laurent

The fuel goes in and out, same as any pump. No where near the crankcase breather. Just like the petcock vacuum hose, this signal will hook to the diaphram side of the pump. If hooked to just one carb, same as the petcock, you get a pulse of vacuum. this will pump the pump. No it should not over pressure your float needles and seats, but if it was set up as a long term soulution, mikuni would recommend smaller diameter sizes for the needle vale. That is the fuel feed hole in the needle and seat assy.
Then you could also use a electric fuel pump for carb's like this Facet, www.google.com/products/catalog?q=facet+...HAw&ved=0CFcQ8wIwAA#
they are preset for 6psi.

Put your carb gauges on it. How many inches of vacuum does it have at idle?

Are you absolutely 100%, no doubts about it, certain that your cams are timed correctly?

Put your carb gauges on it. How many inches of vacuum does it have at idle?

18 cmHg or 7.09 inHg ... stable and all cyls. nearly equals, less than 0.5cmHg diff (manual specify no more than 2cmHg between any two cylinders)

Are you absolutely 100%, no doubts about it, certain that your cams are timed correctly?

Done many times (more than 10 removal of cams) procedure on the FSM for putting the cam chain on camshaft... and trust me i know when i'm a tooth off, pinging and/or backfire through carbs!

For camshaft timing i'm not sure, it has not been slotted and only head as been refreshed (5 thou removed)...


For the vapor lock, i can see it happening ... when engine is fully warmed 45 mins ride when i stop and put the bike on its stand i see the vapor forming (head around 320F which is half inch near!) in the gas line...can't be good!

Quote from wikipedia:

Gravity feed fuel systems are not immune to vapor lock. Much of the foregoing applies equally to a gravity feed system; if vapor forms in the fuel line, its lower density reduces the pressure developed by the weight of the fuel. This pressure is what normally moves fuel from the tank to the carburetor, so fuel supply will be disrupted until the vapor is removed, either by the remaining fuel pressure forcing it into the float bowl and out the vent or by allowing the vapor to cool and re-condense.

/me thinks putting the petcock like the KZ650 from ed650...far away from heat!

regards,
laurent

btw, what are symptom of a bad carb float? It's the only thing i didn't rebuilt yet on carbs!

I do get perfect fuel level .... it's easy to stall the bike when i brake a lot on the front disc.... when i get a fronk fork dive (yes on NEUTRAL and clutch pulled)!!!

regards,
laurent

also, my carb are not straight... a little (LITTLE!) bit angle downward.
Its hanging from the airbox boots but hold like this even without boots from the airbox.

I've checked fuel level last weekend, it was on straight angle ... could that be the problem ?

Little update:

Removed tank , emptied content through prime ... very good flow!

Disassembled the petcock,like new, no cleaning required!

Fuel quality is good here... 1 or 2 mini-particles on the filter

So petcock problem is out of question...

Next --> lowering fuel (1 or 2 mm) in bowls (which is OK 3mm under carb flange), maybe that's why it has a tendency to stall during hard braking...

I was getting fuel boil off at air temps over 90% on my KZ1000, and the beginnings of vapor lock. I lined the outside of my tank next to the engine with heat reflective tape(similar to NASA type material)and put double thickness around the petcock.No more issues.U said your cylinder head temp was 300 plus degrees on hot days?That sounds way hot.I have a temp gauge on my head and it rarely gets over 190 degrees.Oil coolers do work in stop and go traffic,just not as effective.I have a big Satrab cooler and my oil temp on very hot days is 210-220 degrees.I think the 10% ethanol is causing a lot of heat related issues for air and water cooled engines-JMO.bj

I lined the outside of my tank next to the engine with heat reflective tape(similar to NASA type material)and put double thickness around the petcock

Yes you read my mind... i did that yesterday...but a little overkill solution... wrapped the gas line in R12 home insulation (fiberglass wool) 2 inch thickness then a layer of fiberglass cloth wrapped over to keep the wool in place!! Should be enough!

Also increase fuel delivery a little:

New setting

Carburetor:
122.5 main
42.5 pilot
screw 1.5 turn
needle: 4th position from top (5 pos total)

Was:

Carburetor:
120 main
42.5 pilot
screw 1.5 turn
needle: 3th position from top (5 pos total)


Also lowered a little bit fuel in bowls... maybe thats why i was getting stalling on hard braking (fuel was too close and easily drawn when hard braking)


Gonna try right now my new settings

Keep you informed!

Thanks guys!

regards,
laurent