small low end motor.

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Ol'fogasaurus
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Re: small low end motor.

Post by Ol'fogasaurus » Tue Aug 01, 2017 10:26 pm

Not being a real ACVW guy I would check the engine ID number as some blocks are not worth throwing money at. Check the oil pressure at both hot run and cold run (minimum and max RPMs). Check the crankshaft end play, do a compression check, read the plugs to see if they tell you anything (http://www.verrill.com/moto/sellingguid ... rchart.htm) looking for oil or metal on the plugs as well as a lot of other things.

This should give you some idea if it is worth throwing money at or how much money.
Lee

My opinion is worth slightly less than what you paid for it.

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petew
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Re: small low end motor.

Post by petew » Wed Aug 02, 2017 5:51 am

bikesndbugs wrote:
Tue Aug 01, 2017 1:28 pm
The current motor works its just really tired. A whole lot of blow by. I guess I could just do rings. And a hone.

I was holding off on the irs conversion as I dont have the space in my garage at the moment. i planned on trying that next year. and dking motor now.

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Just an idea. If you could find an IRS bug with a rust body on craigslist, you could swap the pans over. That would be quicker and easier. It may even come with a decent motor.

Ol'fogasaurus
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Re: small low end motor.

Post by Ol'fogasaurus » Wed Aug 02, 2017 10:41 am

Travis, its been a long time since I learned the engine condition check tips, probably well over 50 years :oops: :roll: .

If I even "suspect" an engine that I am not familiar with I either pass on it or throw time and money at it making it right the first time. When buying a used or even rebuilt engine listen carefully to what the person says and/or doesn't say also.

A couple of other things to check that I missed the first time:

Blow-by (checking the rings for wear/sealing and valves for seating and being bent): I was going to post a URL/video but a quick check didn't do the job as most of the stuff was either stuff or partly stuff.

To check an engine we used an adapter (quite often home made using a fitting and a spark plug base) that screwed into a spark plug hole that would allow a compressor hos to be connected. When you add air you listen at the intake port and exhaust port for leaking air (both valves have to be in a closed position during the check) and also check in the crank case vent for air flowing out of it (checking for the rings sealing).

Another way to check the rings was to do two compression checks; the first one would be a "dry check" which is your normal compression check. For the "wet check" you squirt some oil into the cylinder then repeat the first check (you could do both in the same hook up but I don't recommend it). The second one you do the squirt into each cylinder individually rather than squirt oil into all the check each cylinder. Write down the numbers for each cylinder both dry and wet values: for future reference, 10% is usually used if I remember correctly.

Also make sure that the engine vent tube is not blocked by either damage or caked on crud and corruption inside of the tube when doing the crankcase check.

Honing the barrels could be OK assuming they are not worn excessively nor out of round. The same for the pistons and inspect the ring lands carefully.
Lee

My opinion is worth slightly less than what you paid for it.

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bikesndbugs
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Re: small low end motor.

Post by bikesndbugs » Wed Aug 02, 2017 3:46 pm

The only problem we've ever had is blow by. My skid plate looks like I have an oil leak but its all out of the oil overflow/crankcase vent.



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Travis
I spend way to much time on this site

Ol'fogasaurus
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Re: small low end motor.

Post by Ol'fogasaurus » Wed Aug 02, 2017 5:07 pm

Travis, part of the problem is what caused the blow-by. If it is age and the engine is just worn or tired causing the blow-by then other things could be worn also; one of the reasons I mentioned checking the valves. If the engine was whooped or not taken care of then you might be in a catch 22 tracking things down w/o splitting the case.
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I even have a stethoscope I use to listen to or locate those "what the hey" noises. It can take a long time to get acquainted with those subtle noises but the obvious ones do stand out. The long probe lets you move it around to locate the origin of the sounds.

When I was starting to play with cars the older (pre WWII) mechanics used either a rubber tube of some (special?) kind mostly to listen to the valve train or to locate other noises or they may use one of those "hundred year screwdrivers" assuming they had one. I tried to find a picture of one but no good results only %#$^&*% (cheap) ones. Basically they were a long blade style of screwdriver with a flattened area for small wooden grips to be added on each side of the screwdriver. They transmit sound quite nicely thank you!

There really is no easy way out a lot of the time.
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