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XL Over heating before shifting to 2nd

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J

JessF

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As the title says, my XL is overheating before shifting into second.

I had to tune the truck for the Dyn 086. After it's poor performance I pulled the 086 off and installed the stock pipe. In trying to retune the engine to what I had before I seem to be missing something.

The engine screams as it goes up the street, but the truck itself is not going that fast and won't to shift into second gear. Messing with the HSN doesn't seem to affect the performance. Adjusting the LSN seems to help, but I'm still overheating.

One thing I'll say, when I was installing the pipe again the header spring snapped back and caught the hose from the tank to the pipe and made a small hole.

Could this small hole be causing the engine to overheat?

Going back to factory settings isn't an option since I had to adjust the needles just to get the truck started and idling for the break in procedure.


any thoughts?
 
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That hole is enough to cause pressure loss, causing it to go lean. Try a new coupler and tell us if that works.
 
I'll have to pick up some hose tomorrow.

I was thinking as well, what if the HSN is set too rich and the LSN set to lean. The only reason I think this is because I tuned both the High and Low needles similtaniously instead of tuning the HSN then the LSN
 
Most likely it is the hole in the fuel line. Drive your XL until it stalls from overheating and then pull the air cleaner off and see if there is nitro boiling in your carb. It will just look like nitro with small bubbles in it.
 
humm, I'd rather not run it till it stalls, but I hear what you're saying.

I'll stop by the LHS tomorrow and get a few feet of tubing to replace the one with a hole in it.

I"m surprised such a small hole could cause this issue. Like, the hole is there, you can see a little white dot in the clear tubing. It's not a crack or a rip or anything larger than the diameter of the spring wire.

the engine never went above 260 during this whole process so I hope I didn't cook anything.
 
Also, if that doesn't cure your problem, check your slipper. If it's slipping too much, it will cause minimal power to actually make it to the trans which will keep it from shifting as well. Even if it does shift, it may be slipping so much that you can't hear it, then with the taller gearing, it just slips even more.

Just fought that battle with my savage and an LRP I put in it.
 
Just intalled the Cen 7.7 pipe and over heating issues continue.

I think my next step is the seal the engine and start the tune from scratch. All four engine mount bolts had come loose during one run, so I wouldn't be surprised if either the back plate or carb has come loose as well.

On another note, the truck runs really quiet with this pipe. Me like.
 
would a loose slipper cause over heating while idling?
 
No, an air leak or being too lean on the LSN will though.
 
well I've ruled out the too lean scenario. Moving on into sealing the engine.
 
JessF said:
would a loose slipper cause over heating while idling?
Click to expand...

It shouldn't. It will drive the heat up when trying to drive the rig though and allow the engine to possibly over-rev. Usually when it's slipping bad enough to cause the engine to overheat, it's melting the spur or slipper pads pretty good too.

High heat at idle would suggest an air leak or bad tune in general and more than likely be a lean LSN. However, an overly lean HSN will cause high temps regardless of the LSN.

Let us know how it goes after sealing it up.
 
Alrighty. Pulled the engine out, checked the pinch bolt, carb and back plate. All these areas were dirty and showed signs of leaking. The only area not leaking was the front bearing.

Picked up some Ultra Copper and set to work. Got to know my engine (engina monologs?). The cleaning and sealing process went smoothly. Let the seals cure for 24 hours and reinstalled the engine. There's a bit of plate in the header seal, and I could see some oil residue after the testing, replacements seals to come.

I had the CEN pipe on it before when it was overheating, so it's hard for me to comment on CEN 7.7 performance gains alone. Fired up the truck and got the HSN and LSN set and WHOOOOSH.

Trucks shifts from 1st to 2nd then 3rd in a predictable manner. leaned out the LSN a bit and had the truck pulling wheelies on the pavement. Checked the temps, never got above 230 while running and started dropping at idle. I'm still running rich on the LSN. Pinching the fuel line cut the engine after 5-6 seconds, still room to breath.

Needless to say it runs much better than before.

I picked up a 15t clutch bell and will see what amount of low end torque I can gain.

Thanks for the imput fellas.
 
Sounds like you got it all banged out. Glad to hear it! Nothing more frustrating than an engine that is fighting you in the spring. If it's the fall... who cares, you can buy a new engine and look at it all winter then bust it up in the spring.
 
Good work, sealing an engine is always a good idea.
 
well I'm right back where I started, not shifting properly then overheating in the process. I'm gone camping all next week and I knew it would just piss me off not being able to work out the problem so I took it to my LHS to have them look it over.

I've spoken to to the fella there several times and his racing history in most all classes I can think of should be of some use to hopefully fix this issue.

If he can't fix it, the truck's going up for sale. Working on this one is detracting from enjoying the others in my collection and IMHO not worth the aggrivation.
 

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