Manx Club

So I finally got the motor in and running (sort of). It is a 1904 (74×90.5) I have a new Weber progressive from aircooled.net and jetted by them as well. I also have a Magnaspark Digital from CB Performance. I don't know what else to do to make it idle. I can't really get to the idle mixture screw while it is running and it gets pretty hot after a while and I can't touch it. I am supposed to be at the Big Bear Bash this coming weekend and really need some advise. Where do I start to fix this? I do have pre-heat setup and working very well. Please help!

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try removing your pre heat set up. your motor sounds like it is overheating. be sure it is getting all available cooling air as possible. if the working pre heat set up removal changes nothing you can just put it back on. find a way to get to the adjustment screw, and adjust it.

Just because it is new out of the box does not mean it is set up right for your buggy.

Here are some Weber carb web sites to look over to help you tune it in.

https://www.racetep.com/manufacturer/ca ... -info.html

http://vw.zenseeker.net/WeberProgressive.htm

http://www.aircooled.net/making-weber-p ... vw-engine/

Keep in mind that Big Bear is around 7000' so it will run fat. I re-jet for the altitude, but others just bump up the timing to get it to run decently.

Worst case scenario is you get it up to Big Bear and there will be a bunch of people there more than willing to turn a wrench to get it running for your.

We run a Weber IDF 40 on our 1776 and it works great.

Assume carb set correct idel out from close 1.5-2 turns. Throutle plate shut then open say one turn. Now mess with timing. I think you are lean try advancing till it runs or bounces off starter. After you get it running dont go over 30 degress total advance

I wrote John at aircooled.net where I purchased the carb kit and he suggested that I check the intake casting for leaks between the pre-heat and the intake runner and sure enough there is a leak between the two. I will replace that section and try again. I really hope I can get this buggy running before the Big Bear Bash, I am really looking forward to it.


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Well I did what I could. Weber even overnighted me a new intake as it seems to me that the old one had a leak between the pre-heat and the intake side of things. Got it timed better but it is running too hot to drive up the mountain this time. We may see you all in the morning.

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Will any updates on your progress

was nice chatting with you in big bear sorry your buggy didn't make it

Mike

Nothing yet. I did get a replacement manifold from Redline Weber on Thursday and installed it Friday morning. It ran better but still too hot. I plan on having someone who is more able to jet this motor running right. I have a suggestion to have Jim at GEMVW work on it. Any other suggestions?

If anyone can get me in contact with Bill in the white buggy with the spare on top and chrome wheels that drove me around all day Saturday in the green group I would really appreciate it. I wanted to thank him but he left too soon and I didn't catch him before he left.


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did you check the warm up vanes to be sure they open ?

lastmanx wrote:did you check the warm up vanes to be sure they open ?

The thermostat and the flaps open up fully pretty quickly, probably within a minute or so. It sure pushes a lot of hot air out the back.


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When we put a new motor in our buggy (1776 with a Weber IDF 40), it ran hot for a thousand miles or so until it loosened up a bit. To combat the extra heat, I had an auxiliary oil cooler bolted to the bottom of the motor and put a finned aluminum sleeve around the oil filter. After running that setup for a couple of years, I ended up cracking the cooler bouncing through a river bed and had to remove it. By then, the motor was well broken in, and we don't need it anymore (averages 190* to 220*). It could be that the motor is just tight, which generates extra heat.

Ok so I've been ignoring it for two months and it was time to get back to it. I was able to get a new thermostat and a jet kit for the carb from Redline along with some tuning advice. I upped the idle jets 10 each and am able to get it to idle now. It pulls well enough after 1600-ish rpm but really any thing just off idle is very temperamental. Now I am still not sure where the problem lies, in the carb or in the timing.

Just triple checking here. I did a compression test and found 170, 170, 160, 165 1-4 respectively. This seems really high to me. Anybody want to weigh in?

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just a quick thought. you do realize you have a drag strip motor? that big of a motor is designed to go from zero to fast in seconds flat. you should not be comparing it to a stock 1600 cc motor built for reliability and ease of use. what you have is a race motor : so go race it, don't idle it.

Do you have the specs on engine other then the size of it?
Compression ratio?
What the specs are for the camshaft?
Cylinder heads, valve sizes?
Timing at idle and full advance?
Spark plugs you are using?
Exhaust size, that would be the size of the tubing?
Muffler, what type?
I know you are saying your engine is getting to hot at idle to work on which could be several things. One is to high of compression ratio for fuel grade you are using, another is to lean of idle mixture, and timing set incorrectly with being retarded or to much advance. A restrictive exhaust system can cause problems too.

The progressive type carburetor has never been the best type to use. As in any center mount carb it needs heat to work properly. Look at the a stock VW setup that use heat riser to use exhaust heat to heat the manifold and a hose from the heater box or a tube picking up the hot air of the cylinder head to the intake of the air cleaner/filter to heat the incoming air. Not having these can cause drivability problems.

The size of you engine does not make it a drag racing engine.

How do you use the buggy? Street, dirt, sand, or?

jsturtlebuggy wrote:Do you have the specs on engine other then the size of it?
Compression ratio?
What the specs are for the camshaft?
Cylinder heads, valve sizes?
Timing at idle and full advance?
Spark plugs you are using?
Exhaust size, that would be the size of the tubing?
Muffler, what type?
I know you are saying your engine is getting to hot at idle to work on which could be several things. One is to high of compression ratio for fuel grade you are using, another is to lean of idle mixture, and timing set incorrectly with being retarded or to much advance. A restrictive exhaust system can cause problems too.

The progressive type carburetor has never been the best type to use. As in any center mount carb it needs heat to work properly. Look at the a stock VW setup that use heat riser to use exhaust heat to heat the manifold and a hose from the heater box or a tube picking up the hot air of the cylinder head to the intake of the air cleaner/filter to heat the incoming air. Not having these can cause drivability problems.

The size of you engine does not make it a drag racing engine.

How do you use the buggy? Street, dirt, sand, or?

The motor has an Engle 110 cam
I do not know the compression ratio. I thought the pressures were a bit high on a cold motor. I have been given different opinions from gearheads my senior that I trust if it is high or not.
Stock heads and valves
14 degrees BTDC at idle
30-34 BTDC depending on manifold vacuum
Bosch WR8AC plugs
Muffler is a Trimill Bobtail with quiet pack muffler. 1-1/2"


The preheat set up works well. I am using the power off of #2 and returns into the center of the collector via stainless flex tubing.




Manifold is not cold. I do not have hot air going into the intake.

I believe I have solved the heat issue and the high idle issue. I have recently put in 55/65 from 45/55 idle jets and this allowed me to have it actually idle and run pretty well. It still has a hard time getting off idle (anything above idle to 1600) and am not sure what to touch next. I have pretty good control over the timing with the Magnaspark digital distributor but I was really hoping for better (any) tuning instructions with it. I can set the timing to just about any curve I want at any rpm and vacuum reference range, I'm just not sure what to change or what to change it to.

Above 1600 rpm it runs well, took it on a hour drive yesterday and it worked well, power was nice after having the tired 1600 in it for so long. It just seem to need more dialing in.

I wanted a street drivable buggy that will handle the mountain roads near me well. I am not a haul ass kind of off roader, at least not yet.

Thank you for any ideas.


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