The spark from your motorcycle's spark plug is responsible for igniting the combustible mixture of air and fuel in the engine. A faulty or damaged spark plug can weaken the engine, limiting its performance or preventing it from starting at all. Regularly checking your spark plugs and checking their ability to generate a spark can prevent problems on the road. The test requires little more than a basic set of tools and an understanding of how to access and remove the spark plugs from the motorcycle.
tips
- An insulator with an ash-white spark plug indicates a lean air/fuel mixture, which creates high temperatures in the engine - replace the spark plug with another spark plug with a "cooler" heat range.
- Detailed specifications and spark plug replacement instructions for your motorcycle can be found in your factory service manual.
- A bright blue spark is a sign of a healthy ignition and charging system. Fully charge your motorcycle battery if the spark is a pale orange hue.
Messages [1 to 20 of 34]
1↑ Topic from Uralchik 09/27/2014 18:27:13
- Uralchik
- Newbie
- Idle
- Registered: 01-06-2014
- Posts: 22
Topic: It's corny, but Ural won't start
Guys, the story is this: I left, drove about 500 meters and the bike stopped pulling itself (in a straight line), started shooting and sneezing, you know. Think immediately: suck out the air. And indeed, oil was seeping under the left cylinder head. There was an aluminum gasket, replaced with paronite. I set the valve clearances by eye, first setting them to TDC (arrow on the flywheel) and adjusting the left one, then returning the right cylinder to TDC. I had no experience with tuning a twin cylinder engine, so I asked my friends how it was done, and that's when I started exhibiting. It seems like everything is set up as before (the gaps feel the same), but the bastard won’t leave! Once I grabbed it once, I screamed at high rpm (for some reason only at high rpm) for about five seconds and it turned off. It didn't start anymore, it didn't even realize it. There is an excellent spark on both spark plugs, I did not touch the ignition carburetors, since before the breakdown they stood and stopped, but before the breakdown the engine flew and did not pass.
Tell me where to start choosing to understand what the problem is?
Eh, I almost forgot to clarify, the battery is fresh, only from charging, unless the bike was in the fresh air, where did the water come from?
2↑ Reply from RaaF37rus 09/27/2014 19:22:37
- RaaF37rus
- Pro
- Idle
- Name: Sergey
- Location: Ivanovo region, Kamenka village
- Registered: 07/27/2013
- Posts: 542
- Reputation: 63
- Motorcycle: IMZ 8-103-10
Re: It’s corny, but the Ural won’t start
Well, it’s better to place the valve not according to the mark on the flywheel, but “at the beginning of the closing of the intake, the exhaust is adjusted, and at the beginning of the opening of the exhaust, the intake is adjusted” the camshaft? Look.
3↑ Reply from Lerych 09/27/2014 19:47:12
- lerich
- Motorcycle dealer
- Idle
- Name: Valery
- Location: Yaroslavl region
- Registered: 01/18/2012
- Posts: 2,138
- Reputation: 215
- Motorcycles: Ural m66, Riga 22, Java 360, Ural 8.103
Re: It’s corny, but the Ural won’t start
so the reason for the dohar may be the carburetors, so they are not in a hurry, and, for example, gasoline may not come from the same tank. I have the same crap he's talking about, loaded and it was running fine and then all of a sudden it won't pull after 5K. The carbies were dismantled and out of breath! there are shock absorbers not of current production, but even gnawed right on the cylinder, which furrows as soon as the tank is clogged in order to pierce the nipples connecting the compartments with a nail. The ignition tends to unscrew, the camshaft bearing has the same property, while the notches no longer match and the valve timing shifts. the valves are usually adjusted strangely. As far as I understand, if you set it from the mark, then one cylinder and the second must be set at 180 degrees, and not from the mark; if not, then all the impacts will occur simultaneously on both cylinders, and this should not happen.
4↑ Reply from Starodumov 09/27/2014 20:39:10
- Starodumov
- WILD HUNTER. Moderator
- Idle
- Location: Permyak
- Registered: 05/16/2012
- Posts: 6,579
- Reputation: 508
- Motorcycle: Dnepr MT 10-36, Ural M 67
Re: It’s corny, but the Ural won’t start
Set the valve, as Seryoga said, check whether gasoline is flowing into the carburetor, then go into the cylinder, check whether the spark plugs are wet or not, check the oil level, one thing I don’t like is that I stopped pulling. Take a look at the ignition at least visually: I recently lost almost a thousand pieces, but it worked, I got lost in looking for the cause. And, of course, the tap needs to be cleaned at least every now and then.
5↑ Reply from SANYa pif 09/27/2014 21:46:37
- Sanya pif
- Elder
- Idle
- Name: Alessandro
- Location: Bely, Tver region.
- Registered: 06-02-2013
- Posts: 4,672
- Reputation: 254
- Motorcycle: Ural 8.103.10
Re: It’s corny, but the Ural won’t start
check if water has entered the carburetor, as it was on the road, unscrew the bottom cover of the housing, look
6↑ Reply from 14 23:39:59
- 666
- Technical support, materials scientist
- Idle
- Registered: 06-05-2010
- Posts: 6,591
- Reputation: 601
Re: It’s corny, but the Ural won’t start
Well, it’s better to place the valve not according to the mark on the flywheel, but “at the beginning of the closing of the intake, the exhaust is adjusted, and at the beginning of the opening of the exhaust, the intake is adjusted” the camshaft? Look.
I do not recommend this method to anyone, the most inaccurate adjustment method, only the most accurate by the TDC mark, if the factory mark is filled in correctly (this is easy to check).. So, we set the TDC, remove the valve cover, no matter which cylinder is left or right , look at the gap... (measure if necessary), an important point, whatever the gap is, we don’t adjust it (we remember), now we make a full turn (360 degrees) and set TDC again. we measure the space again, if the space is larger than the previous one, this is the exact position of the knee: we adjust both valves at the same time.. If the gap in the first version was larger, we will return to it by making another 360 degree turn.. That is, from two knee positions to TDC, we choose where the space is the most, and adjust it there.. Applies to both cylinders..
comrades, help. The left cylinder works intermittently.
I've been scratching my head, which is why I created this topic.
essence. Ural solo 825, keihin 32 cvk, ignition yumen, spark plugs and caps ngk. The problem started gradually. The left cylinder was working fine, but as we drove it began to fail more and more. First, farting from the exhaust pipe at idle, then idling intermittently. Now at idle and at low loads it simply chokes, occasionally jerking when connecting. what did you do. Cleaned, adjusted and replaced carburetors. did not help. I checked for air leaks, made adapters from the Seabihi for the carbs - it didn’t help. I checked the valves for leaks - it didn't help. I checked the valves for tightness both cold and hot - everything is normal. I replaced the head on suspicion of microcracks - it didn’t help. I swapped the spark plug wires (from right to left) but it didn’t help. I changed the coil, the switch, checked the wiring, changed the fuses - it didn’t help. In desperation, I replaced the piston rings - it didn’t help. I inspected the distributor - everything is fine, the cams are in zero, the gear does not play, the phases are not shifted, the key is not cut off, the clearances are normal. I changed the spark plugs, installed known good ones (new ones) and swapped them from right to left - it didn’t help. I don't know what else can be done. I ask for help.
I have a suspicion. My jets in the carbs are 140 VAZ. on the native ones (122) and the call ones 130, it gets very hot, the mixture is too lean. Perhaps, due to such large jets, it will choke at idle when fuel is also sucked from the main system? in operating mode and after driving along the highway, the insulators of the candles are the color of coffee with a small amount of milk.
Shooting into the muffler with one cylinder.
Motor k750. Suddenly there was a popping sound in the muffler as gas was being discharged from the left boiler. Then there were interruptions in the left cylinder. The problem grew worse over 10 km, then went away. Then I stood for a day, came to the garage, started the engine - the same symptoms - periodically shooting into the left silencer when releasing the gas and sneezing when working at idle. If you pull the cable of the right boiler, the set of revolutions is excellent and correct, if the left one, there is a set of revolutions, but with dips and sneezes. I turned the spark plug out - it’s new, the carbon deposits on the electrode are gray. Just in case, I installed another one - there was no improvement. By the way, the deposits on the second boiler are the same. I disassembled the distributor and cleaned the contact on the cover - it didn’t help. I started it on the right boiler, put a spark plug on the left one - the spark was stable and strong. I disassembled the carb without removing it from the motorcycle - the needle was at the top all the way, the jets were turned out and blown out. It didn't help either. 65e carbs. I tried to close the damper in the air vent - both boilers remained unchanged, I tried to leave the suction on the left boiler - the same thing. I don’t really want to try swapping carbs - it’s a bummer, has anyone encountered this? I bought an ICS today - I’ll try to look at the flashes in the boilers and the presence/absence of gaps. Could a lean mixture cause shots in the jammer? I don't think so.
Reasons why a motorcycle won't start
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Problems with carburetors, reasons:
- Lack of fuel in the carburetor.
- Filling (especially when the engine is hot).
- The faucet cup is clogged.
- Incorrect fuel supply to the carburetor.
- The carburetor jets are clogged.
- Water getting into gasoline.
- The float needle valve is dirty or leaking fuel.
- The float is leaking.
- The carburetor jet is not tightened properly.
When the motorcycle is parked for a long time, it may not start. And they say: The Urals will not leave after winter. It may also have difficulty starting in cold weather. These reasons cannot be avoided, since this is an old motorcycle and everything is done according to the old system. There is still a solution to this problem: you just need to dig it well and then warm it up for at least 15 minutes. And in winter, do this from time to time. Then it will start better
Problems with candles. There may be no spark or vice versa.
When there is no spark at the spark plug due to:
- Break the candle.
- Incorrect marking of the gap between the switch contacts, oily or burnt switch contacts.
- Lack of contact at the battery terminals.
- Dirty wire terminals.
- Ignition coil malfunction.
- Broken low voltage cable.
Many people wonder: the Ural won’t start, but is there a spark?!
- There is no play in the valve mechanism.
- Defective piston rings.
- Improper seating of the valves due to burning of the plates or the formation of carbon deposits on them.
- Incorrect fuel supply to the carburetor.
- The carburetor jets are clogged.
- Water getting into gasoline.
- The float needle valve is dirty or leaking fuel.
- The float is leaking.
- The carburetor jet is not tightened properly.
Also common problems:
- Low voltage at the battery terminals.
- Burnout or improper play of switch contacts.
- There is no contact or the capacitor is broken.
The reasons for this may be:
- Incorrect ignition.
- Motor overheating.
- Broken pins, cylinders, pistons, main bearings.
Therefore, if any of the above motorcycle failure problems occur, you should pay attention to the overall performance of the motorcycle. Indeed, as a result, technical problems can not only lead to difficulties in driving, but also affect the driver’s safety.
Why the Ural motorcycle does not start - compression problems
Most often, the compression on a Ural motorcycle is too low. It does not pump fuel into the cylinder, so the mixture does not ignite. There are many reasons for losses:
- — Air is coming out of the valve.
- — Air is escaping from the seal.
- — Air is coming out of the rings.
Pass the pad: Pour water over the ribs and bubbles will appear. In this case, it is enough to replace the seals with Ural ones. If not, we take a syringe of oil from the engine and pour it into the cylinder, working with a special tool. We put it on with our finger. Has compression improved? So the answer to the question of why the Ural motorcycle does not start well should be sought in the rings.
If not, unscrew the lid, placing a liner under it. Note that the valve is in because the stem is a little out and they are not aligned. The one above is clamped. To adjust the gap, you need to loosen the valves on both the right and left. Gently press the valve with your foot. The valves are relaxed.
Check the distances using feeler gauges. Find 0.05 mm and enter the location where the rocker arm connects to the valve. If it doesn't hold up, the gap is too big. Look further. Unscrew the bolts and take the dipstick. We fix it between the valve and the rocker arm and slightly tighten it so that it holds the dipstick. We tighten the bolt and tighten the nut.
Why the Ural motorcycle does not start - other possible problems
If there is still no compression on the Ural motorcycle, do the following.
- — Unscrew the carburetor.
- — We pull out the knee with a hammer (wooden hammer).
- — Unscrew the nuts from the studs.
- - Let's get out of our heads.
How to clean valves? We buy lapping paste and add oils. We smear it on the valve, after making a crack (you will need a drill and a flat nozzle). We put pasta in it and insert the valve. The paste should flow under the valve. To do this, the valve was turned and raised. Dry the pasta with a cloth. A golden frame should appear.
Check the seal with the valve. We install the springs, screw in the spark plug and fill with gasoline to the brim. Everything should be dry. We install the head and adjust the valve. When removing a head with an aluminum gasket, you need to buy a new one (the old one will be flat and air will pass through it). The new gasket is slightly convex, which ensures a tight seal.
This will improve compression on the Ural motorcycle. If the Ural does not start, check the ignition. Unscrew the lid and take a look. Nothing should dissolve. Ignition should be medium. If the foot comes back with a strong kick, the ignition is premature. To turn it on later, you need to move the tab slightly counterclockwise. If the ignition is delayed, the motorcycle may also not start. Then you need to move your leg clockwise.
