Rw Mods

2136 Mingo View Drive Wanamingo MN 55983 us

Any engines not paid for within one year will become the property of Rw Mods.

This video explains everything I do when I rebuild an engine

My recommended break in procedure:

I like heat cycle method for break in. Heat the engine to 240 degrees or so and let it cool before even firing it. Engine heaters like a Competition heat work well but do not get it hot enough for break in. I will put the heater on it for 10-15 minutes and then heat it even more with a heat gun up to at least 240. If you have an engine heater keep it on the engine during break in to keep heat in the engine. You do not want the engine below 200 degrees at anytime when it is running. If you do not have an engine heater a can coolie works well keeping the heat in. Monitor temp frequently.

Starting up the engine I will blow into the exhaust pressure line to get fuel into the engine. With the engine up to temp and a good charged glow ignitor try and start it. It can sometimes take a bit because of the oils in the engine during assembly. On most engines they come from the factory a little rich and can be leaned out a half turn or so before even firing it up. If it does not wan to stay running lean it out, leave the glow ignitor on for atleast a couple minutes. If it dies when you take off the ignitor then it is either too rich or too cold of a plug. On the first firing only run a half a tank or less on the starter box at a high idle monitoring temps often. Stop the engine and let it cool. Repeat the procedure and run the rest of that tank. Stop the engine and cool it again, then run a full tank, you can run the second tank and after in the car on the ground. Be smooth with the throttle and do not use much throttle until the 4th or 5th tank. I like to see atleast 6-8 tanks before running it at the track.

If the engine sticks at tdc carefully pry on the flywheel using the chassis as a pivot, also make sure the engine is not stuck after you shut it down. Always stop an engine by stopping the flywheel with a rubber object and never plug the exhaust to shut it down unless you have to such as a runaway.

How do I send my engine/sleeve in?
You can send your engine in a box or a padded envelope, it does not need to be in the original box. There is no need to clean it before sending.

If just sending the piston and sleeve a padded envelope is the cheapest way to ship, usually only $2.00-$3.00 be sure to wrap it in something to protect it.

I only need payment before sending it back  paypal is  (wait for a total before send $)

Be sure to include return address, e-mail info and a phone # I will contact you if I feel the engine needs new parts such as a rod/bearing. I do not charge if engine is not worth fixing. Please take off clutches and air filters.

Send your package to:

Rex Welch
2136 Mingo View Drive
Wanamingo, Mn  55983
Be sure to include contact info:
--Return address
--phone #

Engine break in also available
$50.00   (with engine purchase)

        Engine Rebuilding   $30.00

--First I take the engine apart and look for any damage or problems.

--After a full cleaning I inspect rod and crank pin wear, check bearings.

--I then clean and shine up the piston top and head button, then I resize the sleeve

to get just the right fit. I do not believe in overpinching, I look for it to be about like the

engine was with a gallon of fuel through it. A very short 2 tank break in is all that is needed.

--I then carefully assemble the engine, I have had many customers claim the engine ran

better than ever.

       Sleeve Resizing      $18.00

If you like to work on your own engines you can just send me your piston and sleeve

to be resized. I will clean the piston top and measure the rod wear and give it a

professional resize. All for just $18.00 return shipping included! (discount on multiple sets)

How long does a sleeve resize last?

Most times a resize lasts as long as it did from new to needing the resize. Example if

you engine had 4 gallons on it before losing compression it should last that long before

needing it again. There are many variables, dirt, heat etc. Preheating is also recommended.

Do I need to break my engine in again?

No, I resize the sleeve to try and get it like the engine when it had a gallon on it so

no long break in is needed. It does help to preheat the engine and run a couple tanks

of fuel with it a couple hours richer. This can be done at the track, make sure to keep

the engine above 200 deg. F or it may lose its pinch faster.