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High Idle speed?


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#41 JWray707

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Posted 05 December 2017 - 02:20 PM

Where is the v notch in relation to the indentation?


V notch is to the right of the indentation.

The bright links are only for initial setup. Once the engine has been fired, you can no longer rely on the bright links for timing info. If the gear ratio were 1:1 then they would be in the same spot for every rotation.
 
Sounds to me like a vacuum leak. Cam timing being off isn't likely to make the engine idle higher than normal. Lower, yes, but higher, not likely.
 
Hanging up throttle linkage or bent throttle shaft also possible. Assuming the distributor is working ok...


Good to know. I won't worry about the bright link then and just set the cam where it's supposed to be.
Pretty sure theres no leaks, unless it's on the carb somewhere, but I sprayrd carb cleaner all around it checking for leaks and it seems tight.
The throttle linkage and shaft are all OK...and the throttle cable is not holding the throttle open.

#42 racerx

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Posted 05 December 2017 - 02:53 PM

I thought he said awhile back that his vacuum was okay.

#43 racerx

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Posted 05 December 2017 - 03:03 PM

From my experience, if its a vacuum leak, the idle is more intermittent, especially if u spray carb cleaner around area then rpm will go up

#44 JWray707

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Posted 05 December 2017 - 03:13 PM

Yeah, my vacuum has always been between 18-20hg. I'll hook up the gauge and check it again just to be sure.

#45 racerx

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Posted 05 December 2017 - 04:02 PM

That's good vacuum. Is the reading steady or jumps around a lot?

#46 JWray707

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Posted 05 December 2017 - 04:24 PM

Just checked it and it was barely hitting 10hg and was jumping alot. Think there's a leak on the carb. I can see the gasket that's not properly fit. Time to delve into that...hopefully that will fix the problem.
Can i use regular gasket material on a carb (incase I need a new gasket)? I have a sheet I can make one from.

#47 racerx

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Posted 05 December 2017 - 06:33 PM

Before doing that, let it run to operating temp. Then spray carb cleaner around base of carb and listen if rpm goes up. If it does, then vacuum leak. Do not gorrila tight...

#48 JWray707

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Posted 05 December 2017 - 08:48 PM

Checked around the base earlier and that was tight...no leak. There was definitely a gap in a part of the gasket on the carb. Spraying carb cleaner at that spot raised the rpm. I just made a new gasket and put it on the carb. Will reattach the carb tomorrow and try it out.

#49 JWray707

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Posted 06 December 2017 - 01:37 PM

So the engine definitely has symptoms of a vacuum leak. Won't go anywhere above 15hg and the needle jumps around, engine very shakey. Sprayed carb cleaner all around to no avail. So...I used the old cigar smoke test. The only smoke that came out was from the primary barrel of the carb. When I had the carb off last night I noticed the the throttle plate or butterfly of the primary barrel was slightly open and couldn't figure out how to close it...just figured it was meant to be a little open. Would that be causing the vacuum leak?
There's always been a fairly loud hissing from this carb aswell as the ones I've had in the past, but that's normal, right?

#50 datzenmike

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Posted 06 December 2017 - 03:44 PM

Isn't this the second carb you put on? Seems like they are shitty supplier.

 

You should be able to adjust the carb almost closed in order to set the idle speed. I don't know what 'slightly open' means without a picture. Slightly open may be perfect. You sure it was the primary that was partly open??? Primary is the one closest the valve cover. Intake vacuum should be 15 -ish at idle. Much lower under full throttle load. And into the 20s when decelerating. 

 

If the gasket don't fix it, I think it's time for a compression test. 


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#51 racerx

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Posted 06 December 2017 - 03:50 PM

So at time it was 18 to 20 hg, is there something u did to the carb after that?

#52 JWray707

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Posted 06 December 2017 - 03:57 PM

This is the third carb! Yeah, shitty supplier...not very detail oriented it seems.
Yes, I'm sure it is the primary. Kinda hard to get a good picture with it on the engine...but it's not supposed to be completely closed I'm guessing?
Good to know vacuum should be around 15.

#53 JWray707

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Posted 06 December 2017 - 03:59 PM

So at time it was 18 to 20 hg, is there something u did to the carb after that?


I've had to swap the carb three different times for various reasons. Don't know what the difference was there.

#54 racerx

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Posted 06 December 2017 - 05:20 PM

Damn, 3x! Get your money back and get it somewhere else. Probably made in China crap. Too bad u can't put a weber 32.36.

#55 JWray707

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Posted 10 December 2017 - 04:51 PM

Just did a compression test and it seems pretty dang low...though I'm seeing that numbers don't matter so much as consistency?
Dry/wet
1. 90/100
2. 90/110
3. 100/120
4. 90/120

What do you guys reckon? It recently started blowing out white/blue smoke on startup and then stops when it's warmed up. Would this be the valves or the piston rings?
Leak down test?
I recently did a block test on it and there was no sign of contamination. Oil color doesn't look too have changed any.
Got it to run and drop in gear but it's at high rpms. 1200 in drive. Seems to want to lurch too. When I put it back in park the RPMS shoot up and stick at 2300-2500.
I have a feeling im headed towards some work...

#56 datzenmike

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Posted 10 December 2017 - 05:08 PM

Three different carbs would not have the same high revving problem.

 

 

Warm up the engine, shut it off and take the throttle cable off. Start it up where's the idle?


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#57 racerx

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Posted 10 December 2017 - 07:10 PM

When u do test, make sure its operating temp., use screw in type of tester not flug in. Yeh, those numbers looks too low,

#58 JWray707

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Posted 10 December 2017 - 08:45 PM

Got it to operating temp and it was the screw in type.
I will try unhooking the throttle cable tomorrow and see if there's any change in rpm.

#59 racerx

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Posted 11 December 2017 - 09:39 AM

Did you open the throttle all the way when you did the test?



#60 JWray707

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Posted 11 December 2017 - 11:02 AM

I didn't open the throttle. I don't have a second hand...guess I could've just wedged it open with something.