Frontier 650 sluggish throttle

  1. Welcome to 6x6 World.

    You are currently viewing our boards as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

    If you have any problems with the registration process or your account login, please contact us. Looking forward to seeing you in the forums and talking about AATVs!
+ Reply to Thread
Results 1 to 7 of 7

Thread: Frontier 650 sluggish throttle

  1. #1

    Frontier 650 sluggish throttle

    Hi, just purchased an Argo 2012 Frontier 650. 40 hours. It sat in a shed for 5 years. Previous owner couldn’t start it so bought new carb to get it running. He changed fuel filter, blew out the lines with air. Put in new fuel then sold it to me. I’ve changed air filter, replaced all fluids and oil filter. I changed the plugs, they were carboned up but not caked.

    Starts straight up and idles quicker and better than before I did all this.
    Down side is opening up throttle their is a lag in revs increasing. It can stall as well. I’ve got it parked where I can’t take it for a run at present. Before any of this it would almost die going up small hills then slowly pick up revs.

    I still need to check the fuel tank vent and fuel line for kinks.

    I assume I’ll have to look at the carb. I’m not familiar with carbies but learn quick I’m a visual learner so pictures help lots.

    Thanks.

  2. #2
    Following this thread. I am having the exact same issue with my Max II which has a B&S Vanguard V-Twin 16hp. I would appreciate any updates you might find, and Ill do the same. I will add, my buddy made some adjustments to the governor in an effort to fix a wavering idle/stalling issue. The engine still wavers on idle and has the same issues you mentioned, but I noticed the sluggish throttle AFTER those adjustments. Throttle response appears good in neutral, but very sluggish under load.

  3. #3
    I’ve just had the carby cleaned. I have fixed jets in my carby so only idle adjustment. Engine is being pulled out to replace crankcase seal so I’ll have to wait till seal kit arrives next week. It will all go back together then and I can test more. Nearby workshop said he often has people come in with fuel filters not OEM and they don’t let enough fuel through under load when partially clogged, so present with similar symptoms. Other possibilities are blocked or restricted fuel line and fuel breather tube. Also possible only one cylinder running so when under load cannot produce enough ooomph! You may be aware of all these possibilities. Will update when I have more feedback. Good luck!

  4. #4
    Since I have had my issues, I changed out my fuel filter for one I ordered online. I'm pretty sure its Chinese. I have an actual B&S filter now, so I may switch it out just to see if that helps, but I'm not holding my breath. I also replaced my main fuel line since the old line had oddly swelled up and collapsed itself nearly the entire length of the line, so there is some truth to what your local workshop told you. Now that I think about it, I did not check the line from the filter to the pump... I will check that line as well. I will just pull that filter/line section out and temporarily run the main fuel line to the pump just to eliminate the fuel filter/old line as the problem. While your waiting on your seal kit to arrive, you should still be able to test your line for clogs by hanging a couple feet of line over the tub into a bucket, and then filling the gas tank with compressed air to push the fuel through the line. Once it starts to flow out the end into a bucket, gravity should keep the flow going. If you have constant flow, you know your line is good.

    I ran the max yesterday and adjusted the idle screw as well, and that seemed to eliminate the sluggish throttle. She sounded better and ran good, but when I left her sitting at idle, I could still hear the engine wavering. I am going to work on this machine until I figure out the problem, but I really hope I do not have to pull the engine. I hope your crankcase seal replacement resolves your issue. I hate it for you that you cant ride for a week. I'm anxious to hear your updates. Ill be sure to post any updates I have and good luck to you too.

  5. #5
    So I ran the max again today, and she ran great. She still wavers some at idle, but Im beginning to think that its not affecting the engine and that its simply the natural idle rythym. Last Sunday it definitely had a sluggish throttle response and much stronger engine surging, including stalling out on the trail, but the idle screw adjustment that I made yesterday appears to have fixed that issue. I may need to take it up an incline to see if it affects the throttle response, but today I took her through mudholes, rough terrain and ran her full throttle with 2 full grown men inside and the throttle response was great. The most she did was waver a little on idle. I can live with that as long as she doesnt die on the trail. She starts on the first crank and she has mostly clean new parts, so maybe Im just being overly concerned.

  6. #6
    Good to hear mate. Enjoy!

  7. #7
    Engine had a sticky valve and a bent rod. Suggestion was probably stuck valve therefore rod bent and only running one cylinder as suggested. Waiting for time to put it back in.

+ Reply to Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts