Fuel flow issue.

[Deuce57]

I let the bike sit too long, and when I went to start it, it tried and tried, but wouldn't. All 4 plugs were carbon fouled. I replaced the plugs and then fuel filter, and turned it on. It wouldn't start. I couldn't see fuel being pulled through the filter, so I ordered a new pump from Partzilla. It still won't start. I found a cracked fuel line (the curved one to the filter) and replaced it. Still nothing. The new plugs are completely dry. I pulled off the fuel line that goes into the tank right in front of the rubber housing for the fuel cap, and blew/sucked on it. Nothing. I'm getting the clicking noise as I should. I actually left the fuel lines off the pump and tried to start it. I couldn't feel suction from either port. Am I supposed to? If there's a fuse to check, where is it? The ones by the pump are good. I also noticed the coils are cracked the length of them, but I am getting a strong spark still. I'll replace them once I get it running.

There is a lack of decent shops around here, so I'm stuck with figuring it out myself. Of course, the learning experience will be worth it. I attached pics of the coils. I haven't checked the price, but I'm sure they're not cheap.

 

[Fire-medic]

Very likely the ignition coils are OK despite the cracks. See CaptainKyle's youtube video about VMax cracked coils and a dissection of one to show that the cracks in the case are usually superficial. You can also search under his screen name here, for the video.

Something is fundamentally wrong if the fuel pump cannot supply fuel to the carb block. Take off the gas cap, and disconnect the fuel line to the fuel filter. Use your air hose to blow backwards, into the fuel supply hose, and listen for the bubbling at the fuel tank neck. It should sound like a babbling brook, as the compressed air bubbles through the fuel hose, and into the tank.

If you don't hear the fuel passing the compressed air, either the tank is empty, or you have some issue.

Do you have fuel in the float bowls? The drain screw on the float bowl, seen at each outside edge at the bottom of the float bowls, should pee whatever fuel is in the float bowl. Capture each bowl in turn, until it's empty, to see what is coming out. Is it filled with debris, fine particulate material, like metal dust, or does it have water in it? The water separates from the gasoline and is easy to see, like a 'lens' floating on the gasoline.

I think it's unlikely that it worked OK before and now is totally-blocked, the gas supply pathway. The gas pump should be able to send fuel from the gas tank through the gas line, the gas filter, and then to the float bowls. You need to re-evaluate the delivery to see what is causing the non-delivery.

 

[Deuce57]

I blew back through the filter, and fuel came out at the gas cap. I also blew through this small line. Very small opening in it, and it just hissed out air. It's getting too dark and hot to check anything else. Possibly a bad fuel pump? It wouldn't be the first time a new part fails. I just think when connected to power and the bike is turned on, I should feel suction at one of the ports, but that's not the case. It is the Mitsubishi brand that came with the bike new.

I have been running ethanol free in it for a few years now and I did put fresh gas in it when I was trying to start it last week.

 

[Fire-medic]

The tiny hole is the pressure relief for the fuel tank.

"I blew back through the filter, and fuel came out at the gas cap" - Was the tank full into the fuel filler neck? Was the gas cap still latched?

 

[MaxMidnight]

Can we assume you are using the choke; what happens if you open the throttle as you are turning the engine over?
Can we assume that you don't have an alarm or immobiliser you haven't disabled? (Yes, I know, only an idiot would fall for that....OK, so I'm an idiot! )

Take the fuel hose off after the pump and put it into a container to catch the fuel. Turn the ignition on and you should hear (and feel) the pump working with fuel flowing into the container.
As Mr Medic suggests, you could also open the drain screws to check there is fuel in the float bowls and if there is any debris.
If the above checks out OK yo have fuel in the system.

You can also check that you have a spark; use an in-line spark tester which makes the process easy.

Lets assume you have spark and fuel and also assume you haven't spontaneously lost compression.

You may have excessive flooding from the aborted starts so remove the plugs and spin the engine over to eject any excess fuel.
Make sure the (new?) plugs are are dry and carbon free and try again.

 

[Deuce57]

Can we assume you are using the choke; what happens if you open the throttle as you are turning the engine over?
Can we assume that you don't have an alarm or immobiliser you haven't disabled? (Yes, I know, only an idiot would fall for that....OK, so I'm an idiot! )

Take the fuel hose off after the pump and put it into a container to catch the fuel. Turn the ignition on and you should hear (and feel) the pump working with fuel flowing into the container.
As Mr Medic suggests, you could also open the drain screws to check there is fuel in the float bowls and if there is any debris.
If the above checks out OK yo have fuel in the system.

You can also check that you have a spark; use an in-line spark tester which makes the process easy.

Lets assume you have spark and fuel and also assume you haven't spontaneously lost compression.

You may have excessive flooding from the aborted starts so remove the plugs and spin the engine over to eject any excess fuel.
Make sure the (new?) plugs are are dry and carbon free and try again.

I'm using the choke, but for some reason, when I went to start it after putting the new plugs in initially, it didn't move as smoothly as it did before. I had to really push down on it for it to engage. I haven't tried the throttle when trying to turn it. on. Like I mentioned, with the fuel lines off of the pump, I feel no suction at all when turning it over. That's why I'm thinking it's possibly a bad new fuel pump. When I get home, I'll check the bowls. I took the plugs out and their clean and dry. To test for spark, I pulled the caps off and using a metal punch, held it in my hand and tried to start it. It's getting spark, lol. I'm hoping Partzilla has good customer service. I don't know if they have a tech line, but I may just go ahead and order another pump. If this one works, then that will solve the problem.

 

[Deuce57]

The tiny hole is the pressure relief for the fuel tank.

"I blew back through the filter, and fuel came out at the gas cap" - Was the tank full into the fuel filler neck? Was the gas cap still latched?

Yes, the gas cap was off. I guess I didn't word that correctly. Fuel came out of the filler neck.

 

[Fire-medic]

Electronic ignitions want to fire sparks, attached to the plug in the engine or out of the engine. You should ground all plugs if you're trying to trouble-shoot. Simple alligator clips leads you can make yourself allow you to ground all the sparkplugs out of the cyl head. Make sure that you have a good ground to the frame or the engine and don't use a painted part for the ground. It's better to have something like a 2 ft double-alligator lead to use from the sparkplug to your choice of ground.

The problem with not having all the sparkplugs properly-grounded is that the TCI (transistor controlled ignition) will have 'made' high-tension energy via the coils, and that energy needs to be delivered either to a properly-grounded sparkplug in the cyl head or to a sparkplug off of the cyl head but grounded with alligator clips. Bottom line is that the ignition box can eventually fail if the energy doesn't have a proper ground.

If the fuel pump isn't working, test for + continuity at the power plug. The pump pressurizes the fuel bowls and then shuts-off, until the engine starts running, then it operates. If you have + something close-to 12VDC with the fuel pump attached, and the pump isn't pumping, something's up with it. Try hot-wiring it from its leads to the battery. It should turn over. If it doesn't, the pump is not working.

 

[brian hicks]

If a working pump tries to run when dry then you should hear an alarming sort of screeching noise from under the seat.

 

[MaxMidnight]

I'm using the choke...it didn't move as smoothly as it did before. I had to really push down on it for it to engage.

Would be worthwhile checking for free movement of the plungers

I haven't tried the throttle when trying to turn it. on. Like I mentioned, with the fuel lines off of the pump, I feel no suction at all when turning it over. That's why I'm thinking it's possibly a bad new fuel pump

Not sure if that is a reasonable test as I doubt that the degree of negative pressure will be that great.
As suggested in my previous post a more reliable check would be to see how much fuel is being delivered.

 

[Deuce57]

Thanks everyone! I have a whole weekend now to aggravate myself, but hopefully get it resolved.

My cousin used to be a service manager for various bike shops. He also suggested checking the plungers on the carbs. Since the choke didn't feel right when I was using it, I will start there, and then move on to checking for correct spark and voltages. Those cracked coils bother me a bit, but I don't think they cracked between the time I last rode it and when I tried to start it again last weekend. I'll search out that video that was mentioned at the beginning of this thread. I may search around for used coils on this site. Question: The coils I do see for sale only have one plug wire attached. I haven't taken them off yet, but is there one coil per plug or do they operate differently than other 4 cylinder bikes? I'm thinking there is another one under the ones I can see.

Sorry for my lack of knowledge on these, but I've always had inline 4s in the past (and still do.) I also downloaded a PDF of the manual, so that should be helpful.

 

[Big"A"]

I let the bike sit too long, and when I went to start it, it tried and tried, but wouldn't. All 4 plugs were carbon fouled. I replaced the plugs and then fuel filter, and turned it on. It wouldn't start. I couldn't see fuel being pulled through the filter, so I ordered a new pump from Partzilla. It still won't start. I found a cracked fuel line (the curved one to the filter) and replaced it. Still nothing. The new plugs are completely dry. I pulled off the fuel line that goes into the tank right in front of the rubber housing for the fuel cap, and blew/sucked on it. Nothing. I'm getting the clicking noise as I should. I actually left the fuel lines off the pump and tried to start it. I couldn't feel suction from either port. Am I supposed to? If there's a fuse to check, where is it? The ones by the pump are good. I also noticed the coils are cracked the length of them, but I am getting a strong spark still. I'll replace them once I get it running.

There is a lack of decent shops around here, so I'm stuck with figuring it out myself. Of course, the learning experience will be worth it. I attached pics of the coils. I haven't checked the price, but I'm sure they're not cheap.

Start with a see thru auto glass filter. It will tell you if you are getting gas from the tank. If no gas you have a problem in tank or fuel pump

 

[Fire-medic]

He also suggested checking the plungers on the carbs

The carburetor enricheners operate via the 'choke lever' on the left front. You can see the movement of the shafts as you thumb-down the lever. If the lever for the enricheners isn't adjusted properly, the lever won't stay in the full-enrichment 'down' position. There is a screw with a nylon washer which can be adjusted to allow the lever to stay-down, and not to slip-upwards partially if you let-go of the enrichenment lever.

You can also see the plungers (part #23, 'starter plunger assembly' on the diagram) attach to the forked stamped-steel 'fingers' which ride on a shaft (part #15, 'starter lever shaft') going across two carburetor bodies. There are two shafts, one for each pair of carburetors. There are four forked 'fingers to actuate the #23 starter plunger assemblies. Be careful with those, their price last time I checked was ~$64. Each.

I use Ron Ayres Yamaha for parts. https://www.ronayers.com/oemparts/c/yamaha_motorcycle/parts
Sean Morley also stocks many OEM Yamaha parts [email protected]

Several things to pay attention to:

• those shafts have small indentations where the set screws for the forked 'fingers' are supposed to fasten-to. If you do a complete stripping of the carbs into four individual components/bodies, those shafts will come-out. You better take lots of pictures to ensure that your carbs go back together properly!
• You need to separate all four carb bodies to get easy access to the enrichment diaphragms. To access the coasting enrichment diaphragms (part #19 'coasting enrichment valve assembly) you do need to separate the carbs into four bodies. Be very careful, as some of the carb bodies are no-longer available, and that goes for some of the parts, like #24, the 'starter body.'

I expect you're either going to find a problem with the electric to the pump, or a bad pump. Clean carburetors adjusted properly are also necessary to work the best they can so pay attention to the carburetor section of the service manual. Proper float levels and clear, open pilot jets are areas often found to cause issues when they aren't adjusted properly (gas float levels) or are plugged-up (pilot jets).

Again, take lots of pictures at every stage of work, to help you do things. I use lots of zip-lock bags labelled with writing on masking tape to keep things sorted. My best results are using an ultra-sonic cleaner. Once in awhile, if an issue persists, it's another trip into the ultra-sonic bath to open a stubborn blockage.

 

[Deuce57]

Well, the short time I spent right now determined I am getting fuel to the carb inlets, but it's not making it any further than that. It's got good flow. I sprayed some carb cleaner in the carbs, and it started, then died. Obviously, my issue is with the carbs. I also want to drain the tank and see what comes out.

I'm trying not to take too many parts off as I'm not comfortable with my memory and reassembly skills. I have been taking pics as I go along. I have to take breaks. It's about 105 degrees out, and probably higher in my garage. My garage faces west, so I may have to wait till the sun goes down to continue.

 

[Deuce57]

It seems my choke plungers are frozen shut (in) with one of the little nibs that catch the choke controller broken off. So, off come the carbs! The problem is where I live, I'm not aware of any reputable shops I can take them to. I tried rebuilding carbs once, and I hated it, and had to take them to a mechanic anyway.

 

[CaptainKyle]

It seems my choke plungers are frozen shut (in) with one of the little nibs that catch the choke controller broken off. So, off come the carbs! The problem is where I live, I'm not aware of any reputable shops I can take them to. I tried rebuilding carbs once, and I hated it, and had to take them to a mechanic anyway.

You can always mail them off to one of us that builds them.

 

[Fire-medic]

CaptainKyle spoke first [email protected]

dannymax is a carburetor specialist withh the VMax constant-velocity (CV) carburetors [email protected]

Sean Morley for all things VMax [email protected]

I've done business with all these guys and you should contact them and see which one you want to fettle those CV mixers.

Be aware that those enrichment plunger assemblies are ~$60 apiece last time I checked with ronayresyamaha.com


https://www.ronayers.com/oemparts/a/yam/50045c0ef8700209bc7942f3/carburetor
Part #20
Starter Set

1GR-1410A-00-00

Retail Price: $73.99

Your Price: $56.00

Be very careful working with your frozen starter pistons as replacing four will cost you $224 not including labor. The starter piston die-cast piece in-which the starter pistons move up/down, are unavailable now from Yamaha. This unavailability is all the more reason to permit one of our recognized VMax specialists with constant velocity carburetors to address your needs. If you aren't 'up' to safely rebuilding your carburetors, save-up your $ and use one of these guys.

The only reason that the Gen. 1 is still on the road is that Yanaha has supported the Gen. 1 far-beyond the federal regulation to do it. We who own them benefit from Yamaha's largesse.

 

[putin]

CaptainKyle spoke first [email protected]

dannymax is a carburetor specialist withh the VMax constant-velocity (CV) carburetors [email protected]

Sean Morley for all things VMax [email protected]

I've done business with all these guys and you should contact them and see which one you want to fettle those CV mixers.

Be aware that those enrichment plunger assemblies are ~$60 apiece last time I checked with ronayresyamaha.com

View attachment 95236
https://www.ronayers.com/oemparts/a/yam/50045c0ef8700209bc7942f3/carburetor
Part #20
Starter Set

1GR-1410A-00-00

Retail Price: $73.99

Your Price: $56.00

Be very careful working with your frozen starter pistons as replacing four will cost you $224 not including labor. The starter piston die-cast piece in-which the starter pistons move up/down, are unavailable now from Yamaha. This unavailability is all the more reason to permit one of our recognized VMax specialists with constant velocity carburetors to address your needs. If you aren't 'up' to safely rebuilding your carburetors, save-up your $ and use one of these guys.

The only reason that the Gen. 1 is still on the road is that Yanaha has supported the Gen. 1 far-beyond the federal regulation to do it. We who own them benefit from Yamaha's largesse.

Just received my carbs from CaptainKyle. Works great.