running rough when hot


IHC in the early to mid-fifties.

Yard Art
Yard Art

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Post Tue Jul 10, 2018 1:20 am

running rough when hot

so im not that mechanically inclined but I have managed this far. where im at is my 54 r110 with an sd220 runs decent when out of gear and cold. I have only taken her for a shot trip around the block and she did not run great once she got hot. if I have the clutch engaged she idles really nice around 300-400rpm. then I drop her in 1st and she bogs right down. she will move but just barely and if I give it more gas she sputters out. the minute I engage the clutch the rpms climb back up and she purrs great again. she runs decent when cold. not great but decent. but once she warms up that's when she bogs. I can also feel a lot of heat coming though the fire wall.
ive taken a timing light to it and ive timed it as close I can to my limited abilities (im learning). the vacuum advance appears to be working in neutral. my neck isn't long enough to see while in gear and the misses isn't brave enough to hood surf. I may have to recruit someone who knows these old point systems, ive asked a couple of my mechanic buddies and there are to young (like me) to get it.
any and all help is appreciated.

-I timed off of tdc #1 using the rivet on the fly wheel
-I advanced a few degrees from there
-timing light on the pulley with the 3 notches showed same notch in same spot, middle in the bottom (that means its good right??)
-I have no tstat in it yet. would that be a reason why im hot? not enough cooling time?
-im in Edmonton alberta if anyone would like beer for time.....
-set up a manual tac and set idle around 300-400rpm
-this was all done at the end of summer and she sat all winter so my memory of doing this is a little fuzzy
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Golden Jubilee
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Post Tue Jul 10, 2018 10:20 am

Re: running rough when hot

Sounds like fuel starvation

Check fuel pump suction, fuel line, tank, carb float, filters,
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Yard Art
Yard Art

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Post Tue Jul 10, 2018 2:46 pm

Re: running rough when hot

Carb lines and filters are new and there is gas going in carb. How do I check suction pressure?
I have a clear inline filter before the fuel pump and it's full of go go juice
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Golden Jubilee
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Post Tue Jul 10, 2018 7:56 pm

Re: running rough when hot

I’m going to toss this suggestion out and its only because I had something similar on a car, not my L.
I had a random stumbling situation (automotive not personal) and it turned out to be a vacuum leak under the carburetor. I guess the gasket cracked or something and caused the leakage. I don’t know what steps you’ve already taken, but check all vacuum hoses and carb gasket for vacuum leakage, carb bolts for tightness. I would assume the intake gasket is good, but you never know. Based on what you’ve said, it’s hard to diagnose the problem long distance, but I’m sure there will be many suggestions for you to try.
L110 owner since 1974, finally rebuilt 2014.

Golden Jubilee
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Post Tue Jul 10, 2018 9:48 pm

Re: running rough when hot

I had a frustrated older man stop at the shop. His L110 was acting as you describe. I asked his if he hjad done any work on the truck, he say he had. Due to his lack of understanding the Old IHC distributor system, he had bolted the distributor down tight to the engine. The vacuum advance on the distributor could not fuinction.
Another thought and this may not be so related, but,...……………. check the grounding straps from the engine to the battery and the ground straps from the cab to the battery. Do not rely on the frame for ground.
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Yard Art
Yard Art

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Post Wed Jul 11, 2018 1:07 am

Re: running rough when hot

Thanks! I do not actually have a ground from my block to frame so I'll try that see how she runs

Yard Art
Yard Art

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Post Thu Jul 12, 2018 7:32 pm

Re: running rough when hot

What I here you describing is it runs kind of ok, when not under load and no power under load and worse when hot- its in the timing - see last post . may be different problem , but same result

Golden Jubilee
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Post Thu Jul 12, 2018 9:07 pm

Re: running rough when hot

Doogybot wrote:Thanks! I do not actually have a ground from my block to frame so I'll try that see how she runs

I don't know what the "H" good that ground to the frame will do for you. The block should be grounded directly to the battery. I think I did say this. -
The ground strap and power cable should never be tight, versus a gentile loop. I have seen tight cables and ground straps pull apart when under power followed by engine failure. When a person goes to look, the cab les are not under engine torque stress and have returned and look complete.
I would rather have tools I do not need than to need tools I do not have
Thinking risks being controversial and possibly being offensive

Yard Art
Yard Art

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Joined: Sun Apr 10, 2016 9:34 am

Post Fri Jul 13, 2018 1:33 am

Re: running rough when hot

I never run things tight, im an electrician by trade and this is one of the few things my experience actually helped with. should I go directly to battery off of the head or just to firewall? I guess to battery would be a better ground. if the ground doesn't solve the issue which I doubt it will I will check my vacuum and advance first then for fuel then go back to timing. im pretty sure I got it pretty close. but as previously mentioned I have no idea really what I was doing. I followed previous forum posts best I could, but ive never done this before and had no one to watch me if I screwed up.
what would I be seeing as far as vacuum pressures? I don't have a way to check this or even know how but I can buy the proper tool if necessary.
I got a new carburetor and have adjusted just the idle. its a Daytona universal 1901. again I don't know what im doing so keep it simple if I missed something. the company I bought it from fired it up before they shipped to Canada so I didn't think I would have to adjust anything.
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Golden Jubilee
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Post Fri Jul 13, 2018 5:55 am

Re: running rough when hot

Just wanted to remind everyone what legendary mechanic Smokey Yunick [allegedly] used to say:

90% of carburetor problems are actually ignition and timing problems.
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