Engine misses and loses power

weretrees · March 21, 2012, 08:13 PM

I have a 73 indian with a 413 in it. It had sat for 6 years. Had a shop rebuild the holly carb on it. They messed it up and then I took it to another shop. He didnt take carb apart but adjusted it and fixed things they didnt do correct. It starts up great. idles fine. Misses tons when you put it in gear. Doesnt have any power on acceleration. Bogs way down. Compression test revealed 70psi all around except two cylinders are at 50psi. So the mechanic says.. What could be wrong with this thing? Could i need to replace the carb with a new one. Or do you think the engines bad? The mechanic thinks the engine is good. checked timing and it was fine. Timing chain has not been checked though.

??Its far away from me and I cant look at it myself. I think I made a mistake in buying it.

ClydesdaleKevin · March 21, 2012, 09:02 PM

The 413 engine was one of the best, if not the best, gasoline engine ever made for RVs in the 70s.

If the carburetor is good, then its probably electrical...Those old things have points...points ignition, not electronic ignition. From the symptoms, I'd say you just need a new set of points, a new condenser, and check your spark plugs, wires, cap, and rotor. Could be a vacuum line as well, especially vacuum advance.

You didn't make a mistake getting a 413...but they are an old design engine and a lot of new young mechanics don't even know what points are, how to adjust them, or how to replace them...lol.

There is also a ballast resistor that if its bad can cause all kinds of weird things to happen...its a cheap part, but it can go bad, and again, new young mechanics probably don't even know what that is.

There are a LOT of posts here on 413s and things that can go wrong with them, and how they were fixed...so browse and read! If the posts don't answer your questions, then ask away.

Don't even worry about the compression for now...check it again after you've run it for a while and the rings have a chance to reseat themselves, and the corrosion wears off the cylinder walls.

And the last thing you have to worry about is the timing chain on a 413...they are WAY heavier duty than necessary...they rarely go bad, even with very high miles.

Kev

Oz · March 21, 2012, 10:42 PM

Use the message search and look at the posts you find using: engine miss (and) engine bogs down. There may be some helpful info in those.

Lefty · March 21, 2012, 11:24 PM

I agree with the info Kevin posted, but I'll add something else to check.
If it starts fine and idles fine, that tells me that the points are firing, and that it is in fairly good time... So I think it's safe to rule out the points,condenser, and ballast resistor... as well as the timing chain. Although the points could very well be improved wit a good filing and re-gapping.
From your symptoms though, I'd suspect a bad or inoperative vacuum advance. That could explain why it misfires under load or at speed. The mechanical advance could also be seized up... which is an easy fix.
As for the compression... try adding 1 oz of Marvel Mystery Oil to each cyl. and allow to soak for a few days. Also, it wouldn't hurt to add some to the crankcase oil either. That should help free up anything in the engine that's sticking.

weretrees · March 22, 2012, 09:51 AM

This motor home is electronic ignition. I am still concerned with the carb. Its old and the shop before messed it up. Any hints on trying to get a refund from a auto shop? I have also told the shop to check the ballast resistor. Im trying to leave them alone, as not to bother them. I would do all this myself but it 6 hours away. Just trying to get it home. so I can work on it. I fix cars everyday and am really bummed that these folks are having so much trouble with it. Oh well.its getting a little epic.The mechanic told me that the vacuum advance is screwy, I said that might be a great start. What do you say to these guys without makin them mad.I know how mechanics can be if you start telling them how to do things. lol. Anyway Im just worried because Im not working on it.

weretrees · March 22, 2012, 09:56 AM

When i do a search with those two titles, my post comes up. I tried a search before and nothing came up that was relevant.I have actually read all the posts and do not think I am stepping on toes. But thanks. Im just trying to get other advise. I dont have the motorhome in my possession to look at it myself.

ClydesdaleKevin · March 22, 2012, 10:41 AM

Type 413 into the search window and a lot of info will pop up, including some of my old posts from my very first RV, The Ark, which had the 413 and some of the same problems you are having.

I ended up putting a brand new Holley on it, and solved some of the problems. New points and condensor solved some more. Fixing a vapor lock problem solved even more, and so on. By the time we sold it because we needed a bigger motorhome, it was running like a top, stopping on a dime, and the only thing it needed mechanically was a new exhaust manifold gasket.

Good mechanics don't mind if you put in your own two cents...you are the customer, after all. They might not take your advice, but a good shop will at least make you feel comfortable in giving it.

As far as getting your money back from the other shop that botched your carburetor job, you can have these mechanics write up something saying the carb job was botched and that they had to fix it...and then bring that document to the other mechanics and see if they'll refund your money...and good honest shop would, or would at least try to make it right in other ways...but good honest shops are few and far between. If they give you a hard time, you can mention to them that you are not afraid to take them to small claims court, and sometimes that threat alone will encourage a shop to give you a refund for shoddy work. The final alternative is to take them to small claims court, with the document from you other mechanics saying the first mechanics botched the job.

Kev

Elandan2 · March 22, 2012, 02:41 PM

The compression seems low. Normally it should be 120-130 psi. You may have burned exhaust valves. With these old engines, unleaded fuel (or propane) is "dry" and the exhaust valves will recede into the seat creating low compression and causing the valves to open too far and then they end up melting. If they were hardened at all, the heads were simply induction hardened in the exhaut seat area which only provided a maximum of about .008" of hardening. But don't dispair; the heads can be repaired with new "stellite" seats and new valves and like Kevin said, they are probably the best motorhome engine ever built and will last forever. Rick

weretrees · March 22, 2012, 08:24 PM

Thanks for your info. Are you guys using a lead substitute in this motor? Im just hoping this shop doesnt try and charge me a lot for a diagnostic. I am not going to pay an extreme amout for them to tell me whats wrong with it. I usually only get an hour of diagnostics for my work. lol

weretrees · March 22, 2012, 08:28 PM

Also, do you guys know of the best way to have one of these towed a long distance? cheapest?
Thats the problem. its far from home.

ClydesdaleKevin · March 22, 2012, 09:22 PM

Burnt exhaust valves on the 413 are EXTREMELY rare...they are sodium filled valves, like a Porche...they really thought these engines out.

As far as a lead substitute goes, you don't really need it with the 413...it already has a low enough compression ratio to run regular gas, although if you ever do have to do a valve job, you can go with harder valve seats...the valves are already hard enough and sodium filled for the exhaust valves.

Make sure if you change out the thermostat, you get a skirted thermostat...very important on the 413 engine...do a message search to see what that means.

Also, there is a grease fitting on the water pump...grease it every time you change your oil, and your water pump will last forever...or close to it.

As far as towing, see if your RV insurance has roadside assistance...most include towing, some 50 miles, some 100 miles, etc. If you have AAA, they might tow it for you as well...I've heard of them towing smaller motorhomes with just car AAA coverage. Other than that, you could get a motorhome tow policy from AAA or Good Sam...and then use it to tow the RV home...cheaper than a tow usually.

Kev

DaveVA78Chieftain · March 23, 2012, 12:39 PM

First, 73 was the only year Dodge used electronic ignition on the 413 engine. 72 and earlier where points. Dodge only used the 440 in 74.
Mark had a vacumm advance problem with his for several years. While this does seem odd, it turned out to be the electronic ignition module. This drove several people crazy (including me) trying to fix the problem before the module was replaced. They can also cause timing shift as another member found out. While they do need to check the operation of the vacuum advance on the distributor (simple hand vacuum pump test), I would recommend you simply start fresh with a new ignition module and dual ballast resistor (another known weak spot; people carry spares with them all the time). Make sure the centrifugal weights in the distributor (under the magnetic pickup plate) are free and working. Sticking weights is a known issue with Mopar distributors and would severly hamper performance if timing is not advanced as engine RPM increases.

The bladder in the Cruise Control (if installed) can rupture due to age. Makes on big vacuum leak.

73 used a Model 4160 Holley (R-6495A). Was the power valve in the overhaul kit and was it the correct version? (1972 and earlier used a #65 power valve where 1973 used a #21) Power valve richens the mixture based on reduced vacuum which is around 6.5hg for 72 and earlier but only 2.1hg for your emmision controled 73 chassis.
(http://www.holley.com/data/TechService/Technical/power_valves.pdf)

Dave

mvptarheel · April 01, 2012, 04:06 AM

I had a '72 413, it lasted longer than the rest of the camper, so I think you have a combination of small problems making it seem like something major when it really isn't.

Missing when you put it in gear: sounds like vacuum leaks. Plug the hose going into the back of the big power steering servo that connects to the carb linkage and see if that hissing noise goes away. Make sure the spark plug wires are on the cap in the right firing order.

Bogging down: Also could be vacuum leaks. The power valve on the carb needs to shoot a stream of gas into the engine when the pedal is pressed, if the engine isn't running it should darn near splash into your eyes if you are looking doun the throat. This is because when the throttle plate opens you lose vacuum until the rpms go up. Also, replace the fuel filter.

With perseverence and common sense I'm hoping you can get it running well enough to get it home. Be sure to check the brake fluid first!

Oz · April 01, 2012, 10:40 PM

I just went through this myself. I found a split in a vacuum line, could hear the hissing. Replaced it and, voila! Problem solved. One of the many things I learned from this group that stands out the most is, start with the simplest things first. Often times, that's what it is.

weretrees · April 02, 2012, 03:17 PM

The auto shop has never called back. I finally called them and told them that I am towing it out of there. They are charging me 400.00 for a compression test and cleaning the carb. I asked them if they figured out what was wrong, and they said Engine.Maybe valves? Its this vehicle worth my time or should I abandon this motorhome? They compression was 70 on 6 and 50 on two of the cylinders. Runs but has no power. Ive paid 4000 for this thing so far. Ughhh...

ClydesdaleKevin · April 02, 2012, 07:24 PM

The way I look at it, if you already invested 4000 bucks, then you can either ditch the rig and lose your 4000 bucks...a lot of money for most of us...or you can fix it...and NOT lose your 4000 bucks, but consider it well invested instead. No one EVER gets their money back out of these old rigs...but to throw one away foolishly that you've already invested a lot of money into is, in my opinion, not the right choice.

But you have to consider other things too though...is the body is good shape and solid? Floors, roof, etc.? Do all your systems work well? AC, Fridge, Furnace, Water heater, etc.? Propane and water lines and holding tanks okay?

When evaluating whether to give up on a rig just because of engine trouble, you have to look at the whole picture. Would fixing the motor more or less get the rig ready to roll without a lot of other expenses, like a new fridge or a total re-roof, etc?

If you had to spend another 2 grand, say, for a good mechanic to get the rig perfectly running, would you have to spend even more on tires, brakes, a 1000 fridge, a 600 dollar AC unit, etc.?

Only you can answer these questions. I for one would at least find out what is wrong with the engine before scrapping it, unless the rest of the RV is a basketcase.

Kev

weretrees · April 02, 2012, 08:27 PM

The inside is good. Needs new carpet, vent covers and generator carb rebuild. Also brake work and stuff. Im not sure about the water system or the fridge. But im starting too think im too far invested to stop. I agree with what you have to say. I will be doing all the work on it when it arrives. I guess your right, its worth nothing as it is... So I might as well finish. It will still be a lot cheaper then a new one and a lot koller loking too.

weretrees · April 12, 2012, 10:33 AM

Well, I got the motorhome here and I have driven it. It starts up fine and idles. It takes a good 20 minutes to warm up. I has a Holly carb on it. When u drive it, it will stumble when you give it gas and then get going. Then you can coax it up to about 35 or so. I can drive it around town a little, but after a birt it will die when accelerating and stumble tons. I looked at carb and it drizzles gas out. no spray out of the top to holes. It kinda looks like a hose that is barely running. No mist just a squirt. one side sprays nada. I am starting out by putting new carb on it. An Edelbrock, Ill keep the holly. I hope this helps a bit. I know little about carbs, but i guess this is one way to learn. Do i need a throttle adapter for the Edelbrock? I bought an adapter plate for the intake, not sure if I need it yet. Lets see how this goes. Do holly's have to sprayers on the primary's? Im not sure, need to do some tinkering.

ClydesdaleKevin · April 12, 2012, 06:08 PM

I'm sure you've probably already thought about this, but maybe your fuel pump is going bad? Or the fuel filters could be clogged...or even the pickup sock in the gas tank might be clogged. If a new carb doesn't completely solve the problem, then you could just be having fuel flow issues...and even old crusty fuel lines could be the culprit...air being sucked in with the gas, reducing the flow of gas to the carb. Vaporlock was another problem we had with our 413. Turns out ours was supposed to have vented gas caps, and a previous owner put sealed gas caps on her...and it ran like crap once it needed a lot of gas for acceleration. Switching to vented caps solved the problem for us. Just some more things to think about.

Kev

Oz · April 12, 2012, 09:48 PM

Yes, the Edelbrock needs a throttle adapter. You can look at Summit or JEGS for the part number.

Lefty · April 12, 2012, 11:09 PM

Before spending much money, there are two tests that you need to have done in order to diagnose the condition of the engine. Neither require a working carb., so you can have these performed before installing the new carb.

Test 1: Compression Test.
You earlier indicated that they did a compression test and that all of the cyl were around 70, with two at 50... I would have this test redone, and this time I will explain the proper way it should be performed.. so you can "supervise" that they give you accurate results and perform the tests correctly.

A Compression test is performed by first removing all of the spark plugs, and then disconnecting the power to the coil.
A Tester is screwed into one of the spark plug holes, and then the engine is turned over with the throttle held wide open... They should turn the engine over at least 3-4 revolutions, recording the highest reading. Then proceeding to each of the next spark plug holes the same way. It is important that the throttle is held in a wide open position to allow air to freely enter into the combustion chambers during the test.
The second test is a "Cylinder Leak Down Test"
This test is performed by moving one cylinder at a time to TDC (Top Dead Center) with both valves in the closed position, and thus should be performed with the valve covers off so the mechanic can visually verify the action of the rocker arms to determine when both valves are fully closed.
A Test Gauge is screwed into the spark plug opening, and then compressed air is applied to the cyl. via a separate hose connection on the test gauge assembly.
With the compressed air attached, he can then pressurize the cylinder. By listening for air hissing at the carb, exhaust, radiator, and also inside the valve cover area, he can determine a lot of useful information.
Air heard at carb.- Burnt or broken intake valves,damaged intake valve seats,bent intake valve.
Air Heard out exhaust pipe-Burnt or damaged exhaust valve,damaged exhaust valve seat, bent exhaust valve
Air at Radiator- Blown head gasket between cylinder and water jacket,crack in head or block between head and water jacket
Air at rocker arm area- Broken or worn rings,cracked piston,blown head gasket between cylinder and oil passage, crack in block or head between cylinder and oil passage.
Leakdown Rate- After applying a set pressure (usually 100 psi), the mechanic will time how long it takes the pressure to fall. There are different rates acceptable for different engines, and a service manual should list the rates for your specific engine. This test is usually performed twice, once "Dry" to determine overall sealing ability, and then again "Wet" with 1 oz of motor oil added to the cyl. This will tell the mechanic whether the rings are at fault, or if the problem is in the heads... if the leakdown rate is slower when "Wet", then the problem is the rings sealing, if there is no change, the problem is in the head.

One added note- It is also possible to hear air escaping from an adjacent cyl. if there is a blown head gasket between the two cyl., so I always performed a Cylinder Leakdown Test with all spark plugs removed.

These tests are rather time consuming when performed correctly, and a shop should charge around 2-2 1/2hrs labor to do both. But they are vital in determining the exact condition of the engine before spending money on unneeded parts or repairs.

Thomas Budzowski · July 28, 2012, 03:34 PM

After installing the 360 into my Brave (I had installed new timing chain set, plugs, wires, dist cap etc) it had no timing marks that I could see, so I spent many hours (days?, weeks?) tweaking the timing as well as tuning the Edelbrock carb I had installed. One day, I pulled the tube off the carb that lead to the vacuun advance and sucked on it with the distributor cap off to see if ignition was advancing and VOILA! Vacuum advance diaphram had a hole in it. When I would suck on diaphragm line, nothing wolud move in dist plus I could also draw air. I looked online at ROCKAUTO>COM to see it part numbers for vac advance diaphragm was same as one on my old 318 I had laying there. The case was that the distributor units had the same part # and I switched the whole dist unit (it was easy). Anyway, ended getting it to run like a champ and towed trailer of about 7000 ponds incluing contents from Pennsylvania clear to the Pacific Ocean and back. Also good Idea to replace fuel filters with see through type such as Fram offers. I installed one prior to carb in doghouse and may also have installed one prior to fuel pump (cant' recall). Anyways, I know how you feel, good luck.

Peace,
Tom.