The sled has speed gear kit and clutch mod., gov. mod, and velocity plate. (As far as I know all Recmotor Parts/kits) Sled starts right up with choke, idles good with choke off, , goes good when moving, however when starting out she has to hold it wide open and bounce on it to get it to start rolling. The sled seems to just BLAAAAAAAH out of the gate, almost like it has no power at take off. Anyone have info on carb, settings that might help? The stock settings for the carb would be great, giving me a place to start. Maybe a diagram of the carb and what screws are what as well??? Any assistance would be very helpful. Cleaned the carb twice for haha's.
Post by Regan Vehring on Jan 4, 2011 16:59:28 GMT -5
To start off we need to figure weather the problem is a motor/carb issue or if it is a clutch and gearing issue. Lift the back of the sled of the ground and rev up the motor, does it sound crisp and clean, if not adj the needles in or out mainly the bottom needle to make the motor run well. know see if the sled has the same preformance when the girl rides it as before. What scares me is that you have a "speed gear kit" if you change the gear for more speed it will have less acceleration, also the other concern is the clutch mod that has been done, if the clutch slip is to high for the maxium torque of the engine it will have a slower acceleration. I'm leaning towards one of these two things that may be causing the problems.
With no weight on it, I wouldnt say its crisp, but it seems to do what it is supposed to. I'm suspecting its carb adjustment. Is there base line settings to go by to start with as far as air mixture and main setting. It does have the adjustable Main jet in the bottom. I have adjusted the main the best it seems I can, I was wondering about maybe the other mixing/adjusting needles?? How do I lower the clutch slip?? It does seem like it could use a little bit more rpm before engagment. almost imediat engagment. I did take the clutch apart last year and cleaned up the dust. I am planning on doing it again this week. Im not convinced clutch cleaning will do much it had the same issue last year after cleaning. When it gets up to speed it does scoot.
This is the clutch set up (www.recmotor.com/products/454/ ), with 35 chain and sprockets, not sure on what the aluminum driven sprocket has for teeth Ill find out that and clutch spring color and shoe setting.
Post by Bob Vehring on Jan 5, 2011 14:54:24 GMT -5
Regan will be back in later, I will make sure he see's this.
Carbs on these are primative at best there is a main on the botom and an ajustment for the idle mixture. There is no real baseline because temp will make it vary. When we ajust them in the shop to dyno, its most often different when it goes outside. If you haven't taken it completely apart this year, I would guess the problem could be the dirt or grunge thae forms in the bowl from sitting durring storage. It only takes a very small bit to plug up the idle circut. The problem is very common with the alky now in most pump gas. Take off the carb, drop the bowl and clean the jets, besure you can see through them, also blow out the passages in the carb. Be sure that the inlet needle and seat are clear. That should e;iminate the carb as a problem. If this doesn't fix it, then we can look at the clutch Bob
Post by Bob Vehring on Jan 5, 2011 17:47:28 GMT -5
Ok, Which clutch do you have, Now, REC has several ,untill lately they pushed something called the Grippster Which is either a copy or a slightly different form of the clutch Noram has made for the karting world from, well at least the early 80's when we started. It is a two shoe design with two big springs on them By todays standards it is a very basic design and IMO not as good as the OEM stock clutch. Tell us in the clutch section which clutch you have, and Jim will come in, he is the clutch expert
Thanks Bob I posted in the clutch forum. The Carb set up I have I have attached a picture of for clearification, and a pic of the plug I pulled last night. Not sure what compression should be but it seems to be about 50-60lbs.
Regan, I stabil and drain and clean carb every year on all my stuff. What is the base setting for the pilot air screw? I think I may be running hot, when I pulled the plug after a couple test runs the tip of the plug went from sooty black (last pic I posted) to brown/light tan whitish and I did change the pilot air screw setting.
Post by Bob Vehring on Jan 10, 2011 10:10:13 GMT -5
I'm sure Regan will answer when he gets in, but something to think about. The biggest thing that effects carb tunning is the temp of the air coming in. To have it "right", means tunning it in a 70 deg shop is going to be differnt then taking it outside where its 30 deg, or -30. Also remember these things do not have an airbox that draws in cold outside air as the engine warms, so does the temp under the hood. Carb settings will vary.
I look forward to any and all responces. I hear that. I have been running it outside right around 30 Deg... Also, what is the effect of High (92) or low (87) fuel octane on these sleds? I saw a coment someplace to only run low octane fuel. Is this true? for all 4 strokes?
Post by Bob Vehring on Jan 11, 2011 10:53:13 GMT -5
Depends, basicly most of what we have followed for decades in terms of fuel (gas) goes out the window with much of todays Alchy enriched fuel. A high octane rated fuel simply resists deto better then a lower grade. Contrary to what some people think, the gas itself does not make more power, actuly less because a a high oct. burns slower, but very little reall power loss. A higher octane fuel allows the engine to be built with more compression, more timing ect, and that is what makes more power. The slower burn of the gas simply lets it resist detonation and live. To your question, a stock or near stock engine should run fine on 87. More of the problem today is with alky added, which draws mosture what you get out of the pump is sometime questionable. Some stations pump alot of fuel and get fresh fuel every week, some puhaps further out, much less often
Post by burningmonk on Dec 5, 2011 21:41:26 GMT -5
hello everyone im new to this site i also no im probably in the wrong sections to ask this but i have a vintage sled and it runs it was parked for ten years and was a pain to clean up, i clean everything off to see what i was working with and there was alot motor was seized so dismantled everything cleaned everything up. anyway i have it run with in two days its a 1977 artic cat el tigre with a 500 cc free air . when idle runs on 2 cylinders but when under load only one? there is fuel going to both carbs and new plugs and gaskets all around so i dont know what the problem was. can someone maybe give me a idea what i could be looking for to fix this problem thanks Ryan