# Techumseh Hard to start



## jsup (Nov 19, 2017)

5HP circa 1997

OK, New spark plug, new carb, runs great once started, however, hard to start. I have two of these motors, one starts right up, the other needs some coaxing to get going.

This particular engine has always been hard to start, which is why I replaced the carb. 

Is there any way to adjust the timing on these things, it seems to me the hard to start one has retarded timing, probably done to make the cord easier to pull. 

HELP!


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## 351beno (Oct 12, 2017)

Probably needs a valve job. The only way to change the timing is to move the cam in the crankcase. You can ck the flywheel key but if it's sheared it's not gonna run good if at all.


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## leonz (Dec 12, 2014)

You may need a new coil which is the most likely culprit as the coils go bad when the coil winding's break down and cannot deliver the high voltage jolt needed for proper spark.

Mice will do a number on the wiring especially on B&S engines with the exposed coil and coil wiring and they also pack in bedding in the fan housing so it may be well your time to take off the fan shroud to see how much junk is under the cowling.


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## Motor City (Jan 6, 2014)

Also check for rust on the flywheel and coil wher it faces the crank. It can effect the coil. Also check the air gap of the coil to the magnets on the flywheel. I just use a business card to set the gap.


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## leonz (Dec 12, 2014)

I don't know if the design for their engines has changed but the late 1960's engines had their coils behind the flywheel.

The nice thing about the B+S coils was that tell you to use the box top flap to create the correct gauge gap every time and it always works.


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## 351beno (Oct 12, 2017)

leonz said:


> I don't know if the design for their engines has changed but the late 1960's engines had their coils behind the flywheel.
> 
> The nice thing about the B+S coils was that tell you to use the box top flap to create the correct gauge gap every time and it always works.


If the coil is under the flywheel it had points the 1995 didn't have points. Tec and Briggs stopped using points around the 70s. The motor most likely will not run if the coil is bad or will shut off after its warmed up.


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## jsup (Nov 19, 2017)

That makes some sense, because it does start with the electric starter, which turns it faster, and more consistently. than a pull start. 

Since I put on the new carb, starting is BETTER than it was, but not perfect, as it should be. One pull start.


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## jsup (Nov 19, 2017)

351beno said:


> If the coil is under the flywheel it had points the 1995 didn't have points. Tec and Briggs stopped using points around the 70s. The motor most likely will not run if the coil is bad or will shut off after its warmed up.


When I see coils go bad, it is typically under heat.

Thing is, once it's started, it runs great.


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## 351beno (Oct 12, 2017)

jsup said:


> That makes some sense, because it does start with the electric starter, which turns it faster, and more consistently. than a pull start.
> 
> Since I put on the new carb, starting is BETTER than it was, but not perfect, as it should be. One pull start.


Head bolts loose? Maybe. I have seen a lot of tec with valve lash wrong even when they where new.


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## GoBlowSnow (Sep 4, 2015)

Good reading here. I've got a 5HP Tech on a JD 524 that is hard to start as well, have to prime 5-6 times and 2 or 3 pulls to get it going no matter the choke setting. Put a new carb on it recently, not much of a difference. Sadly it does not have an electric start.


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## jsup (Nov 19, 2017)

It's an over head valve setup with a gear and lobes off the gear, isn't it? IDK. I can slap together a SBC blindfolded, but don't know crap about these little things.  

I'm selling the machine, and try to make sure anything I sell is as close to perfect as possible. I may be being too much of a perfectionist for this one.


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## jsup (Nov 19, 2017)

GoBlowSnow said:


> Good reading here. I've got a 5HP Tech on a JD 524 that is hard to start as well, have to prime 5-6 times and 2 or 3 pulls to get it going no matter the choke setting. Put a new carb on it recently, not much of a difference. Sadly it does not have an electric start.


If I get a good pull on it, I can get it in 3 pulls. Sometimes more, never less. But it has to be GOOD solid pulls. With the electric start, it's much better. 


It's annoying because I have the same vintage engine that starts on one 1/2 assed pull, every time..


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## JLawrence08648 (Jan 15, 2017)

Some good advice here, clean the coil magnet, make sure the primer is working and doesn't have a hole in the hose - if primed too much gs should be coming out!, adjust the carb, use fresh gas, check the compression - possibly the intake valve is not sealing as well as it should, you may want to try another spark plug - I just bought a new plug for a machine and it was bad, put a used plug in it and it started right away, check the plug gap, should be around .32 I believe, you may have to try another coil and hope for the best, see if you can borrow one as a test.


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## jsup (Nov 19, 2017)

I'm more partial to a leak down test, rather than a compression test. Does that hold true for these motors too? Just wonderin'. I don't see why it shouldn't, but I've been known to be wrong before....


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## 351beno (Oct 12, 2017)

I have never had to do a leak down on a tec. If the compression is lower than 40 psi after 3 pulls. I always take the head off then you can ck the cyl to see if it's egg shaped, scored, and if the cross hatch is good. If that looks good ck the valve lash, guides for wear, and lap the valves in 20 to 45 minute job. After that you should get 60 or more psi in 2 to 3 pulls.


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## classiccat (Mar 1, 2014)

Before you go chasing your tail on ignition issues, you can grab an adjustable gap spark tester (i.e. Thexton tester.) They're nice for getting a feel of spark strength. With your 2 engines side-by-side, you can better gauge what distance the ignitions can throw a nice-blue pop.










Compression testing on these is somewhat qualitative due to the compression release mechanism. I use them for a quick disaster check. Since you already have a leak down tester, have at it...plus it will help isolate any source(s) of compression loss. You'll want to lock the flywheel or PTO to avoid it from spinning when you pressurize the cylinder. 

How does it run once it does start?


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## jsup (Nov 19, 2017)

351beno said:


> I have never had to do a leak down on a tec. If the compression is lower than 40 psi after 3 pulls. I always take the head off then you can ck the cyl to see if it's egg shaped, scored, and if the cross hatch is good. If that looks good ck the valve lash, guides for wear, and lap the valves in 20 to 45 minute job. After that you should get 60 or more psi in 2 to 3 pulls.


Wow, that's easy!


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## jsup (Nov 19, 2017)

classiccat said:


> Before you go chasing your tail on ignition issues, you can grab an adjustable gap spark tester (i.e. Thexton tester.) They're nice for getting a feel of spark strength. With your 2 engines side-by-side, you can better gauge what distance the ignitions can throw a nice-blue pop.
> 
> 
> 
> ...


I have that spark plug tester. That's on my list of things to do today.  That is really a great tool, handy, and a must have for the money. 

It runs perfectly after it's started. NO lean pop that's so common with these, goes up and down the RPM scale without an issue, which is why it's so odd it won't fire up quickly. I engage the wheels and it pulls hard, and doesn't bog. Seems to be OK.


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## 351beno (Oct 12, 2017)

classiccat said:


> Compression testing on these is somewhat qualitative due to the compression release mechanism.


That's the wrong thinking. The compression release is there to help you pull to tdc but should not reduce the compression at tdc much. That's why you need to see how fast the compression builds and use 3 pulls when checking . If it builds slow or sub 40psi its a good bet the cyl or valves are in need of work.


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## classiccat (Mar 1, 2014)

351beno said:


> That's the wrong thinking. The compression release is there to help you pull to tdc but should not reduce the compression at tdc much. That's why you need to see how fast the compression builds and use 3 pulls when checking . If it builds slow or sub 40psi its a good bet the cyl or valves are in need of work.


I agree with that ...that's why I said "somewhat qualitative"; you're getting a ballpark #. For example, you'll get a different # depending on whether you use the e-start or the recoil..and how hard you pull. That's a good suggestion standardizing your method. When you've done it enough times, you know when that engine needs work done. 

The OP said that he has a leakdown tester...even better!


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## GoBlowSnow (Sep 4, 2015)

jsup said:


> I have that spark plug tester. That's on my list of things to do today.  That is really a great tool, handy, and a must have for the money.
> 
> It runs perfectly after it's started. NO lean pop that's so common with these, goes up and down the RPM scale without an issue, which is why it's so odd it won't fire up quickly. I engage the wheels and it pulls hard, and doesn't bog. Seems to be OK.



Same thing on the one I work on, it runs great when started.


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## Dickbelle (Sep 21, 2016)

How about the primer? Is it working properly? Any cracks in the primer or the hose? Is the choke working OK. Try using half choke if its not really cold.


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## vinnycom (Nov 6, 2017)

GoBlowSnow said:


> Same thing on the one I work on, it runs great when started.


if you prime it w/more than a few presses from primer button do u get fuel leaking out of carb, if no, then bad primer.
swap out primer bulb and hose from good working one to the bad one, if still not good switch out the carb from the good one. ths should rule out carb and primer. next is fuel line and fuel cap but if she runs after starting i doubt it would be issues w/them


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## GoBlowSnow (Sep 4, 2015)

Fuel will drip out of the carb just like on any other after priming it 2 or 3 times. Regardless of choke setting it is still difficult to start. Believe me, I've tried it in all the choke settings. Takes 3-4 good solid pulls. Sometimes more. Carb is dialed in right, I even put a new carb on it, same problems. Spark plug gapped properly (It even has an NGK believe it or not) The only thing I haven't tried yet is valve lashing/adjustment. That's the one thing I am not up to par on when it comes to these small engines. Once it is running, it runs well and strong. I may just get a used starter kit off of ebay and throw it on there. I've already broken the pull cord/recoil once, don't want to do that again. This machine is at a semi-remote location so I am not the one who uses it when the time comes that it is needed, I only go out to fix it and run it from time to time when I am out working on something at that building.


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## tpenfield (Feb 24, 2015)

fuel, compression, and spark. . .

Those are the 3 things needed to start an engine, so the hard-to-start engine is not getting enough of at least one of those.

I am not sure what is typical compression for these small engines, nor typical leak test %.

On my Briggs 305cc, If I do a compression test with the pull cord, I get about 75 psi . . . if I use the electric start, I get about 135 psi. Not sure what is typical

On a leak test, I get about 10% leak. Not sure how that might compare to an automobile engine with larger cylinder volume vs the piston ring diameter and perhaps tighter tolerances.


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## Vermont007 (Mar 29, 2015)

I think that compression test is in order.

I recently had an older 5HP Tecumseh on a Chipper present me with similar issues: To replace the Points, I had disassembled one Fall; but failed to reassemble before Spring. And I had left it in my barn over Winter.

Come Spring, and I put it back together, I couldn't get it started. I had Spark and Fuel . . . . but my compression had dwindled to only 45 or 50 pounds !

I reckon that the absence of the Air Filter over Winter had allowed moisture laden air to freely pass through the open combustion chamber and condense on the exposed Exhaust Valve, where it rusted and pitted the surface.

I had to pull the Exhaust valve, have the Stellite (or sealing surface) re-ground and re-seated to allow for a good seal. Once done, my compression went back to nearly 100 PSI and the Engine started right back up.

I suspect that being left outdoors, and knowing that Snowblowers have* NO AIR FILTER* to interrupt the flow of air or capture moisture, this may have happened to the OP . . . . and Tecumseh Engines may have a propensity for their Exhaust Valves to quickly rust and pit when exposed to the elements. Just a hunch.


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## vinnycom (Nov 6, 2017)

if it runs good after it starts wouldnt lack of compression make it run like crap or even be able to start in first place.
imo hard starting is carb(fuel and air) or spark especially if it eventually starts and runs good, if it ran like crap then yes bad valves could be a cause.


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## classiccat (Mar 1, 2014)

vinnycom said:


> if it runs good after it starts wouldnt lack of compression make it run like crap or even be able to start in first place.
> imo hard starting is carb(fuel and air) or spark especially if it eventually starts and runs good, if it ran like crap then yes bad valves could be a cause.


It can run seemingly fine with low compression ...until it's under load where it will bog down to the point of stalling.


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## 43128 (Feb 14, 2014)

i just did valves on one today and it was stupid easy. valve springs can be pried up with a flathead screwdriver and another screwdriver can be used to push the keeper out, same procedure for reinstalling. i ground them to a .10000 gap for both. before it would take 20 pulls to start with starter if warm, make a puffing noise when running, and wouldnt idle now it starts first pull and runs like a champ. extremely common on these engines especially if it came with epa carb from factory. its about an hour and a half its a first time i can get it done in 30_45 minutes


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## jsup (Nov 19, 2017)

Ignorance speaking here. What do the valve seats look like? Do they need to be re-cut? Obvoisly you didn't do it if you do it in 45 min, but is it common to have to do seats? Did you just do valves? Or did you do springs too? Retainers? Guides? Head gasket? What did it cost?


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