Skip to main content
Collection, Preservation and Display of Old Lawn Mowers

Suffolk Punch 75cc engine being used to build a 5 inch gauge railway locomotive - ENGINE WONT START

Enter a word or two to search the forum section and click the Search Forum button.

Hi There

My name is Anton Richards, and for some time now, i have been planning on using an old suffolk lawn mowerrs engine as the means to power a railway locomotive. Now i know this is a lawn mower club, and i may be in the wrong place for this, but i am having real problems getting the engine running, and would love some help and advice as to what can be done, as I am struggling with it, but i am determined to get this engine going, and refuse to purchase another working one.

Now this is the link to what i am trying to build: http://www.cgtrains.com/t869-i-want-to-build-a-live-diesel-for-35-or-5-inch-gauge

 

I have already succesfully created a 32mm/45mm small working model of a nitro/electric gardon locomotive, and now plan to build a bigger ride on version.

Videos of my smaller model can be found here:

http://www.youtube.com/watch?v=xxbXX-u5W04

http://www.youtube.com/watch?v=0RbiuP1vVsw

Now back to the engine...

I have changed the spark plug to a brand new plug, and checked for spark, which it has.

It has compression

Ive cleaned the points with sand paper

and scraped off any carbon that was on piston head, and valves but still refuses to fire.

The one thing i would say it that the spark seems a little week but then again i may be wrong in this.

Could anyone help me

 

Regards

Anton

 

Chris Huxley Sun, 27/05/2012

Hi, I'm no expert, but I've had the same problems with a similar engine. Have you checked the valve timing whilst you have had the head off? I also gave everything in there a wipe clean, I doubt it made a difference other than aesthetically, but it made me feel it helped mentally. I also had a weak spark and it seemed the owner/owners before me had the same problem, as the HT lead was incredibly short, and being a built-in unit, I had to use a spring to bridge a gap. I imagine you have already tried a different spark plug and still end up with a weak spark, so maybe try checking the cap at the end of the high tension lead. I hope my ramblings have helped you in some way, good luck with the build and I look forward to seeing a progressive project to follow :-)

Anton Richards Thu, 11/04/2013

Hi 

Thank you for your reply...

Right, im do not know enough about 4 stroke engines to know anything about valve timing, would you be able to describe it (simply)?

I have given everything a light clean, but to be honest it all seemed strangely clean already :s

Yes my lead is also very short, so ive actually got a crocodile clip from the lead to the spark plug cap, which hasnt seemed to affect the strength of the psark at all...(still seems week)

Did you manage to get your engine running in the end?

Its so frustrating, as i cannot go any further in the project until i know this engine works.

I also forget to mention that i have taken a few things off the carb to give them a clean and pout it back together. I opened the part that has a black float in it, cleaned underneath the float and put back together again...but it seems to be unwilling to work...

 

 

SORRY FOR THE REPEATING OF POSTS, IM STRUGGLING TO POST THINGS/DELETE THINGS.

hillsider Sun, 27/05/2012

Hi,

Re the problems that you have with your Suffolk engine here are some ideas that may help you:-

Use an inline spark booster to extend the original lead or to joint on a new length.

Re check the points and file them clean with a contact file I have found that this removes any scale formation more effectively, then set the gap carefully to the recommended 18 thou. Removing the flywheel will make this task much easier also clean the area around the points thoroughly as traces of oil etc will help prevent a good spark.

I have found that a good squirt of maintenance spray directed into the air inlet will prove if the engine is capable of running. Unfortunately not all sprays work in this mode, I have successfully used Castrol DWF and Morrisons Maintenance spray (there own brand and good price). WD40 for instance is one that does not work . You can use ether based engine starting spray for this also but I personally think that they are a bit harsh on small engines.

If you explore the technical section of this site you will discover that there is a Suffolk engine book contained in there and that may help your progress.

Hope this helps

Ray.

 

Anton Richards Mon, 28/05/2012

Hi Ray

First of all could you tell me what an inline spark booster is?

Regarding the spark, the strange thing is that there is power coming from the ht lead to the spark plug, as when i hold the end of the lead, i get a nice electric shock. The strange thing is that there seems to be no spark, when i attach the lead to the spark plug, and its a brand new spark plug, so i am very confused, as there is current getting to the spark plug, but it wont go through it :s

Ahh yes you say wd40 doesnt work, well i had tried wd40 and it didnt work, so that could be the reaspn why...

Thanks for your reply

Anton

StokesG Mon, 28/05/2012

Hello Anton,The problem maybe the coil or condensor has a fault and may need to be checked.Anton if you take the plate with it sits on to a lawnmower service dealer they can check this for you whlie you wait.Anton this way you will know if this is the problem with the weak spark.Anton another suggestion is the connection of clip into spark plug lead going into new looking copper inside the lead and is secure.Anton you need a good connection onto the copper wire and it needs to be clean copper wire.

redfernmowers Tue, 29/05/2012

I can offer some help from my side of suffolk engines over the years.

some good tips include the following.

1: providing you still have the spark plug connector on the HT lead, if it's an open type, use a stainless steel micro wire brush to polish it to a clean copper. if there's dirt on the connector, that's one area of weakness as dirt can act as an insulator.

2: as stated, ensure your contacts are set to 18 thou clearance. I prefer to use 400g cloth backed abrasive and tightly polishing the contacts. after doing so, use a clean piece of paper a few times to clean debris off. don't use anything else or compressed air, etc.. In certain cases, I then use a micro abrasive at 1000g as a glass finish to the contacts for a little extra help and clean again using paper a few times.

3: with the flywheel removed, use 400g paper to clean the magnets, wipe clean and then 1000g abrasive again and wipe clean. this would help with cleaning any dried in debris or wear. don't be too hard on it, be gentle.

4: fully clean the carb and inspect it. My best recommendation here is to have a container filled with paraffin cleaner, submerge the carb with the filter off and leave it a while. there's nothing worse than debris in the carb, affecting the flow rate of fuel and air as well as it's efficiency. I strip the carb down bare, clean each piece with a nylon micro brush, a tooth brush would be just as good.. ensure that all gasket seals are in good condition. if not, replace so that there's a tight seal. I recommend two options. 1: find the correct gaskets for your carb and replace. 2: I use in certain cases liquid PTFE which really helps in certain conditions with certain older engines. then perform a leak test with liquid leak.

depending on the config of your engine and your fuel tank requirement, one of the most important aspects I advise and always carry out is a replacement fuel hose and in certain areas, replacement tap.

If you still have the filter to the base of the carb, wash in paraffin and dry, clean the filter case too. believe me, it's worth it.

Do a fresh oil change BEFORE a new spark plug. it's a good health check and saves a new plug from instantly being covered in gunk.

have you taken the engine head apart? if not, it's worth doing. remember to remove the spark plug first. then remove the 8 bolts. if the head is still stuck on, a light tap with a screw driver just under the seat will loosen it. don't gouge it. Even though there's great compression, it's worth cleaning out the carbon surrounding the valves, piston, etc. for this, a stainless steel micro wire brush and paraffin. wipe off after each clean. this really helps. repeat for the spark side of the head. this increases the volume and efficiency of the engine.

A good tip is this. if you're going to be using the engine a fair bit, I'd recommend using a fuel additive or even better the new fuels from Aspen Fuels. there's a good number of dealers supplying this. I highly recommend it. you would be best using Aspen 4 stroke fuel. This improves the health of your engine, keeps your carb clean, lasts longer and can be stored for much longer time periods even in the machine, unlike normal fuels. This works wonders with older engines. also available the aspen 2 stroke fuel. already mixed and ready to go.

redfernmowers Thu, 31/05/2012

I assume you're in the UK right? if so, where abouts are you? Can you get to North Wales? if so, it'd be worth popping down to me with your engine and let me see what I can do. The carb needs a full flush. all jets, needles, etc. further to that, it doesn't sound like a timing problem. it sounds like a fuel and ignition issue. 

The best thing I can suggest is to replace the condensor with a new one and HT lead with a decent spark plug connector. that's the one major issue to look at.

try a 20 thou clearance between points. this should help things a little. if the contacts are still dirty then it really needs a clean. You'll know if it's a strong spark like I do by putting a finger on the spark and giving a slow pull. you'll feel it and it will give a heck of a shock (anyone with a pace maker don't do this please)

If the timing's out then the compression won't be right either in a suffolk engine. these things are a pain in the neck.

 

on a different matter, the BSA engine runs nicely now. Had to remove the cylinder and have some work to do.

email me off list at turningbytouch@gmail.com and I'll give you what help I can offer.

 

lew

Anton Richards Thu, 11/04/2013

Right guys, more progress on the locomotive and the mower.

 

I actually found a fully working suffolk lawn mower with an identical looking engine on ebay for £10, so i bought it and just swapped the engines over, and it runs beautifally. This was actually done a while ago, and then the prject lay in the shed for about 6 motnhs as I did not have time, in between the commercial flight training, to mess around with this project.

Here are some clips of the build process, and the mower:

http://www.youtube.com/watch?v=mrqk-vhIbKk

http://www.youtube.com/watch?v=GbbwipPLXkU

http://www.youtube.com/watch?v=BooO8oZglGY

 

Now Not much progress has happened since this, appart from ive got the generator motor, which is from a mobility scooter and a massive 24V 1000 watt. Im using an oldham coupling to join motor and suffolk engine and using the mower clutch, so RPM will govern forward speed.

Please like and subscribe to my youtube channel, as it will keep you up to date with future videos.

 

Now It coming to summer again, Its time I had a lawn mower that actually worked. As you can see from the videos, ive simply swapped the engine and mounts over, but i now have the unoperative engine mounted on the mower.

I thought if i could get another dona mower, and take some parts off of that to get this engine going, then maybe that could work

This morning I purchased another working mower off of ebay, but this one in more need of attention, but engine runs and thats the main thing.

I decided that the easiest thing was to swap the engines over again, as the rest of thelawn mower on the original dona was in ver very good condition and worked very well....but after getting this new mower (number 2 mower) back thismorning, it seems the engines mountings are different and I cant put this engine on the old mower chassis. 

So im back to squar one rwally with a nice lawn mower and a engine that just wont work.

SO IM IN NEED OF MORE HELP PLEASE GUYS

I know this is probably a bit cheeky, but would love for someone in my area to be able to pop round and spend some time with these mowers, as i now have 2 lawn mower and many parts, but just not so much time or knowledge to actually figure out whats wrong. OR I COULD come to you, where ever you are as long as its not to far away??? :)

Im in watford area, Hertfordshire....

Anton

Anton Richards Thu, 11/04/2013

 

Hi There

My name is Anton Richards, and for some time now, i have been planning on using an old suffolk lawn mowerrs engine as the means to power a railway locomotive. Now i know this is a lawn mower club, and i may be in the wrong place for this, but i am having real problems getting the engine running, and would love some help and advice as to what can be done, as I am struggling with it, but i am determined to get this engine going, and refuse to purchase another working one.

Now this is the link to what i am trying to build: http://www.cgtrains.com/t869-i-want-to-build-a-live-diesel-for-35-or-5-inch-gauge

 

I have already succesfully created a 32mm/45mm small working model of a nitro/electric gardon locomotive, and now plan to build a bigger ride on version.

Videos of my smaller model can be found here:

http://www.youtube.com/watch?v=xxbXX-u5W04

http://www.youtube.com/watch?v=0RbiuP1vVsw

Now back to the engine...

I have changed the spark plug to a brand new plug, and checked for spark, which it has.

It has compression

Ive cleaned the points with sand paper

and scraped off any carbon that was on piston head, and valves but still refuses to fire.

The one thing i would say it that the spark seems a little week but then again i may be wrong in this.

Could anyone help me

 

Regards

Anton

hortimech Thu, 11/04/2013

you could just swap the sump from the non-running engine to the running engine, the only thing that you would have to watch out for is the length of the oil thrower on the conrod, if they are different, swap this as well.

 

 

Anton Richards Thu, 11/04/2013

Hi there

 

thanks for your reply.

 

I did this with the two engines that you can see in my links for videos...if you saw them?

 

the problem is on this new machine ive just purchased, it doesnt seem to have a removable sump, like the othet wo...and therefore wont fit onto the better mower...

hortimech Fri, 12/04/2013

Ah, I think that you have a very much later engine that is of all aluminium construction, so you are right, you can't swap the sump.

Anton Richards Sat, 13/04/2013

what i shall do is upload some pictures.....but i cant seem to figure out how to....

Also i dont understand why our conversation is not at the bottom of the page, but half way down? starnge.

 

Anton

wristpin Sat, 13/04/2013

When you sand papered the points did you reset the points gap and then pull some clean thin card through them to remove any grit from the sanding or grease from your feeler gauge?

Unless you or some one else has messed about with the engine the valve timing will be OK - it can only be out if the cam and or the crank have been removed and reassembled without the timing marks being aligned. Igniton timing can only be out if the flywheel has been off and the stator (plate that has the coil, points and condenser nounted on it) moved .

Anton Richards Sat, 13/04/2013

wristpin

Thank you for that, well the valves must be fine then.

 

I will admit i have taken the flywheel off, and removed the coil and plate and replaced again. 

But it also seems as if no fuel is getting to the engine, and ive taken the carb apart and cleaned the whole thing and even soaked it in fuel just so all the dirt and sediment would be removed.

 

In taking off the coil and other parts and putting back on again, the spark seems to have got much weeker....

wristpin Sun, 14/04/2013

Hi Anton - you're not the only one who finds the positioning of replies to threads   rather strange - very easy to look as thought one is hijacking someone else's thread!

On the subject of extending short HT leads I would be wary of using an inline suppressor to do this if you already have a suppressed plug cap or are using a resistor plug. If you have an old engine where the ignition system may already be "marginal" shoving another suppressor in line may be the last straw!

The old cast iron (grey block ) engines had a small black suppressor with an exposed copper loop to connect to the top of the plug which enabled the engine to be stopped by a spring metal"shorting strip" fixed under one of the head studs. There were a bit fragile but are still readily obtainable and are matched to the coil etc.

If your HT lead has been mauled about and is too short my favored repair would be to twist and solder a new bit of HT lead to it and cover with two layers of heat shrink tube. A quick and effective repair with no dismantling required.

On the very old Suffolk magnetos the HT lead was soldered to a tag on the coil so if dismantling is not a problem (remember the nut retaining the flywheel is left hand thread) it's a simple matter to fit a new length of lead as it is with the next generation where the lead "screwed" into the coil - male tapered screw at the base of the recess where the HT lead joins the coil, push the new lead in and twist until it tightens. A bit of sealant between the lead and coil doesn't go amiss.

It was only on the last generation of points ignition coils with the embedded  condenser/capacitor that the HT lead was bonded in and didn't lend itself to renewal

Early black alloy block engines (of Tecumseh parentage I believe) had points ignition with the condenser embedded into the coil but soon switched to a fully electronic system without points.

It should be noted that it is not possible to change from points to electronic by swapping the stator plates as the systems use different flywheels and I believe the the positioning of the flywheel keyway in the crankshaft  is changed in relation to the top dead centre position of the piston.

It is however possible to use one of the after market systems from either Meco or Atom to eliminate the points from either the cast iron or early alloy block engines.

 

Anton Richards Wed, 24/04/2013

wristpin

 

Thankyou so much for your replies, most usefull.

I decided to just go ahead and buy another engine, and actually started a little collection, with 3 complete working suffolk punch mowers, two 17 inch 35s and one very nice 14 inch (much older and in amazing condition).

Well ive also bought a couple of spares and repaires engines to use various parts off of, and its owrked, as ive now got two fully working engines, one on the loco, and another on the mower ive been trying to get going.

Here is the latest video

http://www.youtube.com/user/antonr91

Could you tell me how to upload pictures

Anton Richards Fri, 03/01/2014

Right well I know its been a while since ive posted anything on how the locomotive is coming along, and thier has been majour progress, infct its a fully working chassis now and ive even had several laps round my engineering societyies club track which was great fun until it all went terribly wrong with a huge high speed derailment which left certain parts snapped and others bent....but its all fixed and ready for some more work to be done it in.

Here are the latest videos (although now a little old):

http://www.youtube.com/watch?v=xq7zn9yytXI

http://www.youtube.com/watch?v=9z_V77X8anE

http://www.youtube.com/watch?v=kA3TQzRUZYY

http://www.youtube.com/watch?v=SQkgr9jOqPo

http://www.youtube.com/watch?v=9roPYP-8GKI

http://www.youtube.com/watch?v=zhNYTnAISZg