What is it that is plugging my low speed jets?

I have had this issue since I purchased the car a couple years ago. Car is only driven in the summer a couple thousand miles.

The car starts to run crappy, wont pull at just off idle till it gets on the main. Check the 4 low speed jets and they have some thing restricting them, looks like eye buggers, but slightly more crusty, maybe like dried ones in the AM. I catch it when it is still thin and transparent, not fully blocked, but enough to cause it to cough and spit at 1500 rpm in 4th at about 35-40 mph. Drop it into third and bring up the revs, it gets better, but not right, put the petal down and it cleans up. Clean the low speed jets, and bingo, I start having thoughts about not doing the subbie swap before coming to my senses. This happens a couple time a year.

Their are 2 filters, one between the tank and the pump and one between the pump and the carbs.I was thinking it was the glue in the filters, but looking at the filters, they seem to be intact.

ACVW 1600cc, unknown internals, Empi HPMX 44 carbs, smallest jets listed on their site. Other than needed more HP it runs as good as I would expect from an ACVW when jets are clean.

Just weird, never seen this color of stuff before, brown - whats left of old gas, white whats left of the alcohol, green, whats left of what grew in the water in the alcohol, but what is this yellowish stuff ?

Planning on replacing both filters, but other thoughts appreciated.

Steve

It's the ethanol in the gas. Holly carbs do it too.

Say hello to corn ethanol! Seriously, this stuff is reeking havoc on carburetors everywhere. The only solution is to find and buy ethanol-free gas.

Ethanol, Belch !

Only 10% in my area now, hear in the future we will be going to 15%.

Thanks for letting me know so I am not chasing ghosts.

Steve

I still don't think its the ethanol. That stuff has been in the gas around these parts as long as I can remember. In the 80's and 90's it was labeled oxygenated fuel, but it was just ethanol.

Clean out the tank, and I mean really clean it, bare shiny metal. Replace any old rubber in the system and run a good quality 5 micron fuel filter. IF your car is old enough to be carbed it is old enough to require some serious fuel system maintenance

If the car sits for months at a time use a stabilizer. Put it in the tank and drive around for a day before storing the car. Long term storage is rough on fuel.

I deal with old carburetted cars every day in a professional environment. Some of our customers swear the ethanol is the problem and only run "clear" gas at twice the price. They have the same amount and frequency of issues as the folks like me who fill up at whatever pump happens to be nearby.

I normally don't blame ethanol, but that sounds like an ethanol problem. Do you run the blue stabil?

Some time ago I worked as a lawn and garden service tech. It seemed that there as a lot of crud plugging jets.

Yet in my experience, 40 miles away. I never got this.

I think a lot of this comes from the fuel supply. Get a large open filter and run some fuel trough it.

Ever since there has been ethanol I personally have not had a problem. My old units still have all of the original rubber and aluminum parts.

In reply to Kenny_McCormic:

I do not run stability during the summer but do when storing over the winter.

Was thinking of trying the Joe Gibbs stuff. Hoping it's more than just naphtha.

Steve.

In reply to lrrs:

Is this a spring issue or throughout the season? When you clean the jets are you checking out the bowl too?

AFAIK marine stabil (blue) is still the gold standard. Though for additional protection I like to pour 2 stroke oil down the bowl vent if it's going to sit a while, seems to help.

Jumper K. Balls wrote: *snip* Clean out the tank, and I mean really clean it, bare shiny metal. Replace any old rubber in the system and run a good quality 5 micron fuel filter. IF your car is old enough to be carbed it is old enough to require some serious fuel system maintenance *snip*

Worse case replace the tank with a new clean one. Looks like a Beetle tank is about $140.

In reply to Kenny_McCormic:

Depends on when last cleaned. Sat for a week went for a drive yesterday and was not sure I would make it home. Cleaned today went for the same drive, smooth, well as smooth as you can expect a acvw to run. Last cleaned before this time was June and before that last fall some time. I have not checked the bowls as the carbs are like down draft webber and the tops have to come off and I don't have a set of gaskets, probably a good idea to get a set of i don pick up a subaru enine soon. It does not look like crud, it looks like growth, like alge but yellowish.

I've seen that yellow stuff you speak of and I don't think it's growth, but some sort of precipitate you get when modern gas gets old or wet.

I'd probably run stabil year round if it's sitting for a week, or maybe just isoheet if you think it's exclusively a moisture issue. The modern fuel goes bad fast, both from the ethanol sucking up water in non sealed tanks and from the higher volatility of the modern stuff regardless of corn content.

I'm not in favor of ethanol but we have to live with it. I have no problems similar to what has been reported. My mower and snow blower will soon be called antiques. I use a little Stabil when I put them asleep for 6-7 months. Always start right up when awakened. Maybe it's the low humidity.

Jumper K. Balls wrote: I still don't think its the ethanol. That stuff has been in the gas around these parts as long as I can remember. In the 80's and 90's it was labeled oxygenated fuel, but it was just ethanol.

I know it's not the ethanol, because fuel here has been 10% ethanol for thirty years (at least) and these kind of problems just don't happen.

Knurled wrote:

Jumper K. Balls wrote: I still don't think its the ethanol. That stuff has been in the gas around these parts as long as I can remember. In the 80's and 90's it was labeled oxygenated fuel, but it was just ethanol.

I know it's not the ethanol, because fuel here has been 10% ethanol for thirty years (at least) and these kind of problems just don't happen.

In New England, at least MA and NH, we had MTBE in place of Ethanol, until the point about 5 -8 (maybe more) years ago when they could not figure out why they were finding MTBE in the water supply when there where said to be no leaking tanks in the vicinity.

So today's project, a riding mower at the GF's that quit while mowing last year and a lawn that was 8 inches tall, push mow, I think not. I knew what it was it was the anti backfire solenoid, while I was trying to figure out why it was not staying lit, and the float bowl was off I figured I would check the main jet. It to had the yellow stuff. This mower has a plastic tank and a filter between the tank and the carb. Tank was clean, but the jet had the same yellow film blocking the orifice, its weird, there is no sign of this stuff any where except in the brass jets. I am beginning to think it may be some sort of reaction with the brass.

Any way, anti backfire solenoid, arggg. Never needed one of these in the past, when did people become so lazy that they cant throttle down before turning off the key, if they did, there would be no need for this part and no wasted time trying to figure out why its not working. GRM'd it, it will never be the problem again.

Steve

In reply to lrrs:

I removed the anti backfire noid on one once, put in a normal bowl bolt off a parts carb, worked fine, no jet change or anything.

Kenny_McCormic wrote: In reply to lrrs: I removed the anti backfire noid on one once, put in a normal bowl bolt off a parts carb, worked fine, no jet change or anything.

Thought about that but clipped the needle instead and stuck it back on. I think the issue was with the connector, the solenoid had flat pins, the connector, round contacts. I squished them down to make a better connection however, it did not last, tired of messing with it and the lawn was not getting cut, I clip the needle and got to mowing.

Steve

Clean and etch the tank, flush the fuel system, replace all filters, add inline filters right before the carbs and rebuild those down to bare bodies.

See if 0% ethanol fuel is available near you, or run marine Sta-Bil, always.

Startron get my vote over Stabil. I run it in everything year round. Seems to work good, Have not had any problems in the past 5 years. So I stick with it. The heard of xr100's (dirt bikes) for winter storage get drained, then blown dry thru the gas line then filled up with Marvel Mystery Oil. I do this out of pure habit and the fact there's 6 of them and cleaning six carbs in the spring would be a big time hassle this way I drain the oil(they have drain screw)add some fresh gas and run it.

In reply to 44Dwarf:

I've been known to do something similar mothballing cars, once it's fogged, battery out, etc. I pour 2 stroke oil down the vent to overflowing.

So, today, a co-worker tells me his TR-6 is running again. Back in 2001 he drove it into his garage and parked it cause another co-worker that had just started (back in 2001) had one that was restored, and after seeing cw2's car he lost interest in his and started focusing on his V-Tech powered CRX. Drove the TR-6 into the garage, only storage prep, turning off the key.

This past weekend, he put a new battery in it, and turned the key, and after come cranking, its running, well enough that he registered and insured it, and is taking it for state inspection this weekend.

Asked what he found in the carbs and informed me they never came off the car and no carb cleaning took place, not only that it was same gas that was in the tank in 2001. MTBE oxygenated fuel, not Ethanol.

I am amazed.

I have never seen his TR-6 as I was doing the night shift at the time, should get to check it out next week.

Steve

The ethanol is reacting to something in the fuel system. My guess, based on repairing more than a couple of small engines that ran fine until they got e10 in them is that its one or all of these 3 things.

1. Ethanol is a solvent, its dissolving crud built up somewhere that true gasoline didn't.

2. Rubber fuel lines or other rubber bits in the system that are not compatible with e10.

3. Gaskets that are not compatible with e10. I saw this a lot on Briggs engines.