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Themo quad help in CT #2238191 01/21/17 12:00 AM 01/21/17 12:00 AM
Joined: Apr 2003 Posts: 915 near New Haven, CT F fireeng OP super stock
fireeng OP super stock F Joined: Apr 2003 Posts: 915 near New Haven, CT	I have a restored/rebuilt thermoquad built by Scott Smith at Harms in 2012. I only had the carb on the car for a few hours and I could never get it to run right so I went back to my original carb. It is on a stock build 340 auto with these specs the motor was bored 40 over the piston is 10.1-1 compression the heads are 68cc the cam is rated for 275hp Idle-good power range 1500-4500 duration .050 AT.066 210/220 279/290 intake lift .429 exhaust lift .442 overlap 51 Now my original carb has developed a fuel leak, idles poorly and bogs out and stalls if you punch the gas from a stop. I sent the car in to my mechanic to swap back to the carb built by Harms. He agrees the car runs better with the Harms carb but there is still a flat spot that will stall or bog the car if you don't feather out the gas just right. He thinks the carb may need a new accelerator pump. He is not confident with working on the thermoquad due to his lack of experience with them. Does anyone have any leads on someone who could work on this carb for me? I am in CT near New Haven. The closer the better but I am willing to send it out to try to get it running properly. Thanks for any help. 2016 Diesel Ram 3500 Mason Dump 1971 Challenger 2013 Jeep Wrangler 1979 Dodge Ram Power Wagon 400 Mini Pumper My other car is a Fire Truck.

Re: Themo quad help in CT [Re: fireeng] #2238207 01/21/17 12:27 AM 01/21/17 12:27 AM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	Quote: Now my original carb has developed a fuel leak, idles poorly and bogs out and stalls if you punch the gas from a stop. (1) where is it leaking? (2) you might shoot a 2 second blast of starting fluid into each idle mixture port with the thin red straw then reinstall the screws & see if it straightens out & if not it might have a vac leak. (3) is there an immediate/healthy squirt of gas when you tip the throttle? floats not waterlogged, needle & seats not leaking? live every 24 hour block of time like it's your last day on earth

Re: Themo quad help in CT [Re: RapidRobert] #2238218 01/21/17 12:43 AM 01/21/17 12:43 AM
Joined: Apr 2003 Posts: 915 near New Haven, CT F fireeng OP super stock
fireeng OP super stock F Joined: Apr 2003 Posts: 915 near New Haven, CT	unfortunately, I don't know the answers to any of your questions. I have very limited mechanic skills. Therefore, I rely on others......and pay dearly for it 2016 Diesel Ram 3500 Mason Dump 1971 Challenger 2013 Jeep Wrangler 1979 Dodge Ram Power Wagon 400 Mini Pumper My other car is a Fire Truck.

Re: Themo quad help in CT [Re: fireeng] #2238223 01/21/17 12:47 AM 01/21/17 12:47 AM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	You might give Scott a call & go from there. live every 24 hour block of time like it's your last day on earth

Re: Themo quad help in CT [Re: fireeng] #2238234 01/21/17 01:17 AM 01/21/17 01:17 AM
Joined: Dec 2007 Posts: 18,157 Mass DAYCLONA I Live Here
DAYCLONA I Live Here Joined: Dec 2007 Posts: 18,157 Mass	Originally Posted By fireeng I have a restored/rebuilt thermoquad built by Scott Smith at Harms in 2012. I only had the carb on the car for a few hours and I could never get it to run right so I went back to my original carb. It is on a stock build 340 auto with these specs the motor was bored 40 over the piston is 10.1-1 compression the heads are 68cc the cam is rated for 275hp Idle-good power range 1500-4500 duration .050 AT.066 210/220 279/290 intake lift .429 exhaust lift .442 overlap 51 Now my original carb has developed a fuel leak, idles poorly and bogs out and stalls if you punch the gas from a stop. I sent the car in to my mechanic to swap back to the carb built by Harms. He agrees the car runs better with the Harms carb but there is still a flat spot that will stall or bog the car if you don't feather out the gas just right. He thinks the carb may need a new accelerator pump. He is not confident with working on the thermoquad due to his lack of experience with them. Does anyone have any leads on someone who could work on this carb for me? I am in CT near New Haven. The closer the better but I am willing to send it out to try to get it running properly. Thanks for any help. The TQ is very dependent on the accelerator pump to provide smooth transition, unfortunately the accelerator pump is a poor design susceptible to a variety of ills, esp if the carb is allowed to dry out, the longer the period, the worst it gets...you didn't mention exactly were the fuel leak is? I'd suggest you talk to Harms, once you send a previously serviced item off to another party, you either void any warranty or future guarantees of service on said item(s) with the original provider...unless it's your choice for reasons not known to move towards another provider of services Mike

Re: Themo quad help in CT [Re: fireeng] #2238327 01/21/17 11:32 AM 01/21/17 11:32 AM
Joined: Jan 2003 Posts: 1,893 Harriman NY 7 71GTX471 top fuel
71GTX471 top fuel 7 Joined: Jan 2003 Posts: 1,893 Harriman NY	It needs to be inspected/diagnosed & dialed in by a competent carb/tuner guy.Maybe member gdonovan could help you out he mite be close enough to you & I know he's a savvy tuner. Last edited by 71GTX471; 01/21/17 11:47 AM.

Re: Themo quad help in CT [Re: fireeng] #2238419 01/21/17 02:23 PM 01/21/17 02:23 PM
Joined: Feb 2003 Posts: 21,318 Manitoba, Canada DaytonaTurbo Too Many Posts
DaytonaTurbo Too Many Posts Joined: Feb 2003 Posts: 21,318 Manitoba, Canada	In your case I would give scott a call. He is very active on this board and I suspect he would be happy to help you.

Re: Themo quad help in CT [Re: fireeng] #2238647 01/21/17 09:11 PM 01/21/17 09:11 PM
Joined: Jan 2003 Posts: 3,623 Millinocket, Maine J JonC master
JonC master J Joined: Jan 2003 Posts: 3,623 Millinocket, Maine	Check the dashpot, if it isn't working the air valve will open late and very quick resulting in a great big bog. Also same thing if air valve is not adjusted right (very loose). 11B40

Re: Themo quad help in CT [Re: JonC] #2240268 01/24/17 03:47 AM 01/24/17 03:47 AM
Joined: Jan 2003 Posts: 27,421 Balt. Md 3 383man Too Many Posts
383man Too Many Posts 3 Joined: Jan 2003 Posts: 27,421 Balt. Md	Originally Posted By JonC Check the dashpot, if it isn't working the air valve will open late and very quick resulting in a great big bog. Also same thing if air valve is not adjusted right (very loose). Actually if the choke/secondary air valve vacum diaphram is ruptured and leaking where it dont work at all then the air valve would open to soon as the choke vacum break/airvalve unit will slow the rate the airvalve opens to conrtol its opening rate so it dont open to fast and cause a bog from to much air all at once. And of course the secondaries wont open at all until the choke valve is fully open. Have you tried stepping on the gas nice and easy to see if it drives ok like that. If it does that tells its not to lean on the transistion circuit when it dont need the acell pump. If it drives good like that but stumbles when hiting tha gas a litle faster I would want to look close at the acell pump circuit and make sure its working good. If it stumbles even on the gas real easy then it may be lean and may even have the metering rods adjustment off. But as said Scott knows these carbs very well and if he built it I am sure he will assist you if you call him. Good luck , Ron Last edited by 383man; 01/24/17 03:50 AM.

Re: Themo quad help in CT [Re: fireeng] #2240354 01/24/17 12:50 PM 01/24/17 12:50 PM
Joined: Jan 2003 Posts: 42,714 Spokane Washington ScottSmith_Harms Mr Wizzard
ScottSmith_Harms Mr Wizzard Joined: Jan 2003 Posts: 42,714 Spokane Washington	Very simple. I warrant any and all work 100% against build defects for as long as you own it! I doubt you will see that warranty matched elsewhere. But you need to contact me or I can't help you. Also,once a 3rd party gets involved it can complicate the issue and depending on the circumstances,can void your warranty. Based on what I've read here so far I am going to guess that the problem is not the carburetor build, but rather the adjustments that have been made to it (or not) or some other non carburetor related engine issue. Either way, I'll try to help you, just give me a call

Re: Themo quad help in CT [Re: ScottSmith_Harms] #2240915 01/25/17 10:46 AM 01/25/17 10:46 AM
Joined: Apr 2003 Posts: 915 near New Haven, CT F fireeng OP super stock
fireeng OP super stock F Joined: Apr 2003 Posts: 915 near New Haven, CT	Thanks Scott. My plan was to call you but I was hoping to get some help locally to see if the issue could be remedied by a simple adjustment or if in fact the prob could be ruled out of the carb all together Another issue is with my lack of skills, I can't even be "talked" through a problem or procedure cause most times I get lost pretty quickly. I took the recommendation above and reached out to gdonovan and we are going to try to meet in a month or so and he will take a look. Thanks again, I'll be in touch soon, Scott T 2016 Diesel Ram 3500 Mason Dump 1971 Challenger 2013 Jeep Wrangler 1979 Dodge Ram Power Wagon 400 Mini Pumper My other car is a Fire Truck.

Re: Themo quad help in CT [Re: fireeng] #2240948 01/25/17 11:50 AM 01/25/17 11:50 AM
Joined: Jan 2003 Posts: 42,714 Spokane Washington ScottSmith_Harms Mr Wizzard
ScottSmith_Harms Mr Wizzard Joined: Jan 2003 Posts: 42,714 Spokane Washington	No problem. Also, since it was 5 years ago, you might want to check your (ENTIRE) fuel system for contamination. It's VERY common for bad gas to cause all kinds of problems, and even if everything front to back was brand new 5 years ago it could be bad now of any amount of fuel sat in it. .02 This was an O.E. winning Challenger, it sat for a few years and this was what it looked like, pretty on the outside, no so much on the inside. Car started and ran, but not very well. Of course, the carb got blamed but once cleaned out turned out that it was fine (and I didn't restore it, someone else did).

Re: Themo quad help in CT [Re: fireeng] #2240949 01/25/17 11:51 AM 01/25/17 11:51 AM
Joined: Jan 2003 Posts: 42,714 Spokane Washington ScottSmith_Harms Mr Wizzard
ScottSmith_Harms Mr Wizzard Joined: Jan 2003 Posts: 42,714 Spokane Washington	Nice huh? That's not as much rust as it is bad gas turned to a sticky brown residue. That sending unit was brand new when installed.

Re: Themo quad help in CT [Re: ScottSmith_Harms] #2240970 01/25/17 12:32 PM 01/25/17 12:32 PM
Joined: Feb 2005 Posts: 28,312 Cincinnati, Ohio Challenger 1 Too Many Posts
Challenger 1 Too Many Posts Joined: Feb 2005 Posts: 28,312 Cincinnati, Ohio	Originally Posted By ScottSmith_Harms Nice huh? That's not as much rust as it is bad gas turned to a sticky brown residue. That sending unit was brand new when installed. This also happens when the tank is stored not full. It should be 100% full and it won't do that. Store your car with leaded race gas or gas with no ethanol in it is my suggestion. I stored mine for 18 years, started the car about twice a year. Kept the tank full or nearly full through the years. I got the car out of storage in 2003 and drove it a lot until 2014 with the same tank, fuel lines and carb. Then the tank got a dent in it from road debris summer of 2014 and started leaking. I had to replace it, but there was no rust inside.

Re: Themo quad help in CT [Re: Challenger 1] #2241165 01/25/17 06:51 PM 01/25/17 06:51 PM
Joined: Apr 2003 Posts: 915 near New Haven, CT F fireeng OP super stock
fireeng OP super stock F Joined: Apr 2003 Posts: 915 near New Haven, CT	fingers crossed my guts don't look like that! 2016 Diesel Ram 3500 Mason Dump 1971 Challenger 2013 Jeep Wrangler 1979 Dodge Ram Power Wagon 400 Mini Pumper My other car is a Fire Truck.

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