Indian Motorcycle Forum banner
  • Hey everyone! Enter your ride HERE to be a part of MAY's Ride of the Month Challenge!

1 - 20 of 23 Posts

·
Registered
Joined
·
11 Posts
Discussion Starter · #1 ·
Hello,

My name is Tomas and I live in Czech Republic in Central Europe. And of course sorry for my bad English.

I am contacting all of you for advice when I am finding a solution for my specific problem. I believe that there are skilled mechanics among you with many years of experience can help.

I recently bought an Indian Four motorcycle from 1932.
The bike is after a complete renovation, including the engine.
And just when the engine was running in, a fault appeared that I can't handle.
The third cylinder burns the mixture imperfectly, it works at about 30%, the spark plug is after disassembly wet and unburned.
The other cylinders work without problems.
I was able to rule out a fault on ignition, including another cables and spark plugs (I use NGK AB-6).
This indicates me a problem in the mechanical part.
The compression on all cylinders is about 4.6 atm (67.601 PSI). Valve clearances are: intake valve=0.15 mm (0.59 in), exhaust valve=0.25 mm (0.98 in).
The engine willingly starts and responds quickly to the accelerating of throttle.
That the cylinder does not work properly, despite the spark plug spark gives, I detected using a thermal camera (see attached, heat difference between 3rd (70.73°C=159.31 F) and 4th cylinder (127.15°C=260.87 F) .
I want to ask you for advice if someone would give me the answer where to look for a problem solving.
I've heard that third cylinders have always had a problem, but I can't believe it's been over 1 hour engine run-in.

Thank You for all your advices and responses.
 

Attachments

·
Registered
Joined
·
2,643 Posts
You say compression is good on all cylinders, as is valve clearance. It is obviously getting spark and fuel since the temp is up. That would leave ignition timing. Interesting that on the second picture you posted the front and rear cylinders are noticeably hotter than the middle ones. Given that air flow to the center cylinders was known at the time to be compromised by the design, it would not surprise me to find that the engineers of the time had elected to retard the timing on different cylinders by different degrees to attempt to make the engine less prone to failure. I know for a fact that the Germans did on Volkswagen air cooled flat fours for exactly this reason. (The #3 cylinder ignition cam lobe in the distributor is ground with a few degrees of retard to make up for less air flow due to its position and the oil cooler taking some of the air flow.) If the engine is running well otherwise and it were mine I'd run it and keep an eye on it to see if it developed any other issues. I mean, thermal imaging wasn't a diagnostic test when that bike was made, LOL. This might be perfectly normal.
 

·
Registered
Joined
·
369 Posts
Fairly even compression check rules out a blown gskt,I would check for a leaking intake gskt.Don't know what type of oil rings are used but if put on upside down everything would check out cylinder wise but would keep oiling plugs creating a misfiring cylinder.
 

·
Registered
Joined
·
1,272 Posts
Pic of the bike PLEASE!!!
 
  • Like
Reactions: CaptFlood

·
Founding member / Distinguished
Joined
·
2,049 Posts
Howdy @Heldy ,
Given that your compression is even across the board, I'd suspect an ignition problem. Try swapping the plug and plug-wire to another cylinder and see if the problem travels with it. If you have a spare distributor cap try swapping that out. Also, given that the fresh engine has only one hour of run in, the higher temp might just represent more friction on a tightly fit piston and it will free up with some more careful break-in miles. I've rebuilt many cast iron-cylindered, air-cooled engines, it can take up to 1,500 miles / 2,414 km for them to run-in. During that time the motor should run progressively quieter, smoother, and cooler. Keep clean oil in it and avoid prolonged idling or sustained high-speed runs. I like to run up the engine revs then cut throttle and coast down on compression at intervals during the break-in miles.
--- Randall
 

·
Registered
Joined
·
385 Posts
Take a common squirt bottle filled with diluted dish detergent and spray around the intake nuts with it running. If it foams you have a leak. It's a simple test that shows a leak or rules it out to let you move on to something else. You may also want to contact Mike Tomas at Kiwi Indian. [email protected]
 

·
Registered
Joined
·
11 Posts
Discussion Starter · #8 ·
Take a common squirt bottle filled with diluted dish detergent and spray around the intake nuts with it running. If it foams you have a leak. It's a simple test that shows a leak or rules it out to let you move on to something else. You may also want to contact Mike Tomas at Kiwi Indian. [email protected]
Thank you for the good advice and contact.

I was looking for a leak a week ago. paradoxically problematic cylinder number 3 was OK. I found tears on the suction/head at cylinder number 2. but really a little. Suction problem or timing make sense. I'm starting to think that if the problem is not the camshaft and the material removed on it, then only the electricity. I'll probably have to try another distributor. Last hope.
 

·
Registered
Joined
·
11 Posts
Discussion Starter · #9 ·
Howdy @Heldy ,
Given that your compression is even across the board, I'd suspect an ignition problem. Try swapping the plug and plug-wire to another cylinder and see if the problem travels with it. If you have a spare distributor cap try swapping that out. Also, given that the fresh engine has only one hour of run in, the higher temp might just represent more friction on a tightly fit piston and it will free up with some more careful break-in miles. I've rebuilt many cast iron-cylindered, air-cooled engines, it can take up to 1,500 miles / 2,414 km for them to run-in. During that time the motor should run progressively quieter, smoother, and cooler. Keep clean oil in it and avoid prolonged idling or sustained high-speed runs. I like to run up the engine revs then cut throttle and coast down on compression at intervals during the break-in miles.
--- Randall
Thank you. Interesting experiences. Of course, I tried change spark plug among themselves, also new one. I changes wires among themselves and add new one. By this step I ruled out a malfunction on wires and plug. Next one is a distributor with cap of my friend. I'll get to that next month. I will answer you then.
 

·
Registered
Joined
·
11 Posts
Discussion Starter · #11 ·
Fairly even compression check rules out a blown gskt,I would check for a leaking intake gskt.Don't know what type of oil rings are used but if put on upside down everything would check out cylinder wise but would keep oiling plugs creating a misfiring cylinder.
So, I checked all gaskets. They are as good as they can be on a 90 year old machine :) I suspected that the exhaust on cylinder 3 was clogged. But it is not. No. 3 is absolutely clean, without carbonized elements on it. Missing the explosion.
 

·
Registered
Joined
·
11 Posts
Discussion Starter · #12 ·
have u checked for any sort of leaks around the head gasket? maybe leaking to another cylinder?
I probably checked everything I was able to do based on my experience with engines, it occurred to me that it could escape to another cylinder through the intake. I'm working on it. I will let you know.
 

·
Registered
Joined
·
11 Posts
Discussion Starter · #13 ·
You say compression is good on all cylinders, as is valve clearance. It is obviously getting spark and fuel since the temp is up. That would leave ignition timing. Interesting that on the second picture you posted the front and rear cylinders are noticeably hotter than the middle ones. Given that air flow to the center cylinders was known at the time to be compromised by the design, it would not surprise me to find that the engineers of the time had elected to retard the timing on different cylinders by different degrees to attempt to make the engine less prone to failure. I know for a fact that the Germans did on Volkswagen air cooled flat fours for exactly this reason. (The #3 cylinder ignition cam lobe in the distributor is ground with a few degrees of retard to make up for less air flow due to its position and the oil cooler taking some of the air flow.) If the engine is running well otherwise and it were mine I'd run it and keep an eye on it to see if it developed any other issues. I mean, thermal imaging wasn't a diagnostic test when that bike was made, LOL. This might be perfectly normal.
Interesting reading. I found that the spark plug is wet. There is petrol in the combustion chamber, but it doesn't explode. The piston in the cylinder is as clean as the word of God. If they thought of cooling the problematic 3rd cylinder, then it's just fine, really, but I'm afraid this will unfortunately not be the case. I wish you were right but I'm still looking.
 

·
Registered
Joined
·
1,408 Posts
Hello,

My name is Tomas and I live in Czech Republic in Central Europe. And of course sorry for my bad English.

I am contacting all of you for advice when I am finding a solution for my specific problem. I believe that there are skilled mechanics among you with many years of experience can help.

I recently bought an Indian Four motorcycle from 1932.
The bike is after a complete renovation, including the engine.
And just when the engine was running in, a fault appeared that I can't handle.
The third cylinder burns the mixture imperfectly, it works at about 30%, the spark plug is after disassembly wet and unburned.
The other cylinders work without problems.
I was able to rule out a fault on ignition, including another cables and spark plugs (I use NGK AB-6).
This indicates me a problem in the mechanical part.
The compression on all cylinders is about 4.6 atm (67.601 PSI). Valve clearances are: intake valve=0.15 mm (0.59 in), exhaust valve=0.25 mm (0.98 in).
The engine willingly starts and responds quickly to the accelerating of throttle.
That the cylinder does not work properly, despite the spark plug spark gives, I detected using a thermal camera (see attached, heat difference between 3rd (70.73°C=159.31 F) and 4th cylinder (127.15°C=260.87 F) .
I want to ask you for advice if someone would give me the answer where to look for a problem solving.
I've heard that third cylinders have always had a problem, but I can't believe it's been over 1 hour engine run-in.

Thank You for all your advices and responses.
I highly recommend you contact the guys at Wheels Through Time Museum in Maggie Valley, Tennessee USA.
They have an amazing Indian expert and I'm sure he can help.
 

·
Bronze member
Joined
·
2,950 Posts
These guys are in the United Kingdom might be able to help , or know someone who can .
INDIAN MOTORCYCLE CLASSICS
AMERICAN IRON IN THE UNITED KINGDOM
Technical Index
feel free to contact us using the form on this page or direct on;
telephone +44 7973 696236
email [email protected]
 

·
Bronze member
Joined
·
1,294 Posts
Get ahold of Crazy horse Moto, Mark is his name. He is over there in Ausie land. Here is the link to his page Facebook. Tell him I sent you, he has a world of knowledge over there!
 
1 - 20 of 23 Posts
Top